diff --git a/.gitignore b/.gitignore
index 503b769..0517ac2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,8 +12,12 @@
 teststore2
 dev1
 dev2
+dev3
+dev4
 derby.log
 hadoop-conf-tmp
 metastore_db
 teststore
 output
+tmp
+dist
diff --git a/algebricks/algebricks-common/pom.xml b/algebricks/algebricks-common/pom.xml
index 87f7004..a6279b9 100644
--- a/algebricks/algebricks-common/pom.xml
+++ b/algebricks/algebricks-common/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>algebricks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -41,7 +41,7 @@
   <dependency>
   	<groupId>edu.uci.ics.hyracks</groupId>
   	<artifactId>hyracks-api</artifactId>
-  	<version>0.2.7-SNAPSHOT</version>
+  	<version>0.2.10-SNAPSHOT</version>
   </dependency>
   </dependencies>
 </project>
diff --git a/algebricks/algebricks-compiler/pom.xml b/algebricks/algebricks-compiler/pom.xml
index dbacd2f..f276439 100644
--- a/algebricks/algebricks-compiler/pom.xml
+++ b/algebricks/algebricks-compiler/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>algebricks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -41,12 +41,12 @@
   <dependency>
   	<groupId>edu.uci.ics.hyracks</groupId>
   	<artifactId>algebricks-rewriter</artifactId>
-  	<version>0.2.7-SNAPSHOT</version>
+  	<version>0.2.10-SNAPSHOT</version>
   </dependency>
   <dependency>
   	<groupId>edu.uci.ics.hyracks</groupId>
   	<artifactId>algebricks-core</artifactId>
-  	<version>0.2.7-SNAPSHOT</version>
+  	<version>0.2.10-SNAPSHOT</version>
   </dependency>
   </dependencies>
 </project>
diff --git a/algebricks/algebricks-core/pom.xml b/algebricks/algebricks-core/pom.xml
index 0fd538e..ac8cd89 100644
--- a/algebricks/algebricks-core/pom.xml
+++ b/algebricks/algebricks-core/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>algebricks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -41,27 +41,27 @@
   <dependency>
   	<groupId>edu.uci.ics.hyracks</groupId>
   	<artifactId>hyracks-storage-am-btree</artifactId>
-  	<version>0.2.7-SNAPSHOT</version>
+  	<version>0.2.10-SNAPSHOT</version>
   </dependency>
   <dependency>
   	<groupId>edu.uci.ics.hyracks</groupId>
   	<artifactId>hyracks-storage-am-rtree</artifactId>
-  	<version>0.2.7-SNAPSHOT</version>
+  	<version>0.2.10-SNAPSHOT</version>
   </dependency>
   <dependency>
   	<groupId>edu.uci.ics.hyracks</groupId>
   	<artifactId>hyracks-dataflow-std</artifactId>
-  	<version>0.2.7-SNAPSHOT</version>
+  	<version>0.2.10-SNAPSHOT</version>
   </dependency>
   <dependency>
   	<groupId>edu.uci.ics.hyracks</groupId>
   	<artifactId>algebricks-runtime</artifactId>
-  	<version>0.2.7-SNAPSHOT</version>
+  	<version>0.2.10-SNAPSHOT</version>
   </dependency>
   <dependency>
   	<groupId>edu.uci.ics.hyracks</groupId>
   	<artifactId>algebricks-common</artifactId>
-  	<version>0.2.7-SNAPSHOT</version>
+  	<version>0.2.10-SNAPSHOT</version>
   </dependency>
   </dependencies>
 </project>
diff --git a/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/algebra/operators/physical/AssignPOperator.java b/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/algebra/operators/physical/AssignPOperator.java
index aea04b2..55da00e 100644
--- a/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/algebra/operators/physical/AssignPOperator.java
+++ b/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/algebra/operators/physical/AssignPOperator.java
@@ -38,6 +38,8 @@
 
 public class AssignPOperator extends AbstractPhysicalOperator {
 
+    private boolean flushFramesRapidly;
+
     @Override
     public PhysicalOperatorTag getOperatorTag() {
         return PhysicalOperatorTag.ASSIGN;
@@ -76,7 +78,8 @@
         // TODO push projections into the operator
         int[] projectionList = JobGenHelper.projectAllVariables(opSchema);
 
-        AssignRuntimeFactory runtime = new AssignRuntimeFactory(outColumns, evalFactories, projectionList);
+        AssignRuntimeFactory runtime = new AssignRuntimeFactory(outColumns, evalFactories, projectionList,
+                flushFramesRapidly);
 
         // contribute one Asterix framewriter
         RecordDescriptor recDesc = JobGenHelper.mkRecordDescriptor(context.getTypeEnvironment(op), opSchema, context);
@@ -92,4 +95,8 @@
         return true;
     }
 
+    public void setRapidFrameFlush(boolean flushFramesRapidly) {
+        this.flushFramesRapidly = flushFramesRapidly;
+    }
+
 }
diff --git a/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/algebra/operators/physical/IndexInsertDeletePOperator.java b/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/algebra/operators/physical/IndexInsertDeletePOperator.java
index 2f9417b..879f2a9 100644
--- a/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/algebra/operators/physical/IndexInsertDeletePOperator.java
+++ b/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/algebra/operators/physical/IndexInsertDeletePOperator.java
@@ -83,6 +83,7 @@
         scanVariables.add(new LogicalVariable(-1));
         IPhysicalPropertiesVector r = dataSourceIndex.getDataSource().getPropertiesProvider()
                 .computePropertiesVector(scanVariables);
+        r.getLocalProperties().clear();
         IPhysicalPropertiesVector[] requirements = new IPhysicalPropertiesVector[1];
         requirements[0] = r;
         return new PhysicalRequirements(requirements, IPartitioningRequirementsCoordinator.NO_COORDINATION);
diff --git a/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/algebra/operators/physical/InsertDeletePOperator.java b/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/algebra/operators/physical/InsertDeletePOperator.java
index d8b7c33..c85bfb9 100644
--- a/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/algebra/operators/physical/InsertDeletePOperator.java
+++ b/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/algebra/operators/physical/InsertDeletePOperator.java
@@ -73,6 +73,7 @@
         scanVariables.addAll(keys);
         scanVariables.add(new LogicalVariable(-1));
         IPhysicalPropertiesVector r = dataSource.getPropertiesProvider().computePropertiesVector(scanVariables);
+        r.getLocalProperties().clear();
         IPhysicalPropertiesVector[] requirements = new IPhysicalPropertiesVector[1];
         requirements[0] = r;
         return new PhysicalRequirements(requirements, IPartitioningRequirementsCoordinator.NO_COORDINATION);
diff --git a/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/algebra/prettyprint/LogicalOperatorPrettyPrintVisitor.java b/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/algebra/prettyprint/LogicalOperatorPrettyPrintVisitor.java
index 9c5de9c..49ec269 100644
--- a/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/algebra/prettyprint/LogicalOperatorPrettyPrintVisitor.java
+++ b/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/algebra/prettyprint/LogicalOperatorPrettyPrintVisitor.java
@@ -349,7 +349,7 @@
     @Override
     public String visitExtensionOperator(ExtensionOperator op, Integer indent) throws AlgebricksException {
         StringBuilder buffer = new StringBuilder();
-        addIndent(buffer, indent).append("statistics collection");
+        addIndent(buffer, indent).append(op.toString());
         return buffer.toString();
     }
 
diff --git a/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/algebra/properties/AsterixNodeGroupDomain.java b/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/algebra/properties/DefaultNodeGroupDomain.java
similarity index 75%
rename from algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/algebra/properties/AsterixNodeGroupDomain.java
rename to algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/algebra/properties/DefaultNodeGroupDomain.java
index ab2cde2..226f02c 100644
--- a/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/algebra/properties/AsterixNodeGroupDomain.java
+++ b/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/algebra/properties/DefaultNodeGroupDomain.java
@@ -14,21 +14,17 @@
  */
 package edu.uci.ics.hyracks.algebricks.core.algebra.properties;
 
-public class AsterixNodeGroupDomain implements INodeDomain {
+public class DefaultNodeGroupDomain implements INodeDomain {
 
     private String groupName;
 
-    public AsterixNodeGroupDomain(String groupName) {
+    public DefaultNodeGroupDomain(String groupName) {
         this.groupName = groupName;
     }
 
     @Override
     public boolean sameAs(INodeDomain domain) {
-        if (!(domain instanceof AsterixNodeGroupDomain)) {
-            return false;
-        }
-        AsterixNodeGroupDomain dom2 = (AsterixNodeGroupDomain) domain;
-        return groupName.equals(dom2.groupName);
+        return true;
     }
 
     @Override
diff --git a/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/jobgen/impl/JobBuilder.java b/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/jobgen/impl/JobBuilder.java
index eb1e99c..1fe6b15 100644
--- a/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/jobgen/impl/JobBuilder.java
+++ b/algebricks/algebricks-core/src/main/java/edu/uci/ics/hyracks/algebricks/core/jobgen/impl/JobBuilder.java
@@ -26,6 +26,8 @@
 import edu.uci.ics.hyracks.algebricks.common.utils.Pair;
 import edu.uci.ics.hyracks.algebricks.core.algebra.base.IHyracksJobBuilder;
 import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.AbstractLogicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.AbstractLogicalOperator.ExecutionMode;
 import edu.uci.ics.hyracks.algebricks.runtime.base.IPushRuntimeFactory;
 import edu.uci.ics.hyracks.algebricks.runtime.operators.meta.AlgebricksMetaOperatorDescriptor;
 import edu.uci.ics.hyracks.api.dataflow.ConnectorDescriptorId;
@@ -73,6 +75,11 @@
         if (pc != null) {
             pcForMicroOps.put(op, pc);
         }
+        AbstractLogicalOperator logicalOp = (AbstractLogicalOperator) op;
+        if (logicalOp.getExecutionMode() == ExecutionMode.UNPARTITIONED && pc == null) {
+            AlgebricksPartitionConstraint apc = new AlgebricksCountPartitionConstraint(1);
+            pcForMicroOps.put(logicalOp, apc);
+        }
     }
 
     @Override
diff --git a/algebricks/algebricks-data/pom.xml b/algebricks/algebricks-data/pom.xml
index 613d692..b61a701 100644
--- a/algebricks/algebricks-data/pom.xml
+++ b/algebricks/algebricks-data/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>algebricks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -41,12 +41,12 @@
   <dependency>
   	<groupId>edu.uci.ics.hyracks</groupId>
   	<artifactId>algebricks-common</artifactId>
-  	<version>0.2.7-SNAPSHOT</version>
+  	<version>0.2.10-SNAPSHOT</version>
   </dependency>
   <dependency>
   	<groupId>edu.uci.ics.hyracks</groupId>
   	<artifactId>hyracks-data-std</artifactId>
-  	<version>0.2.7-SNAPSHOT</version>
+  	<version>0.2.10-SNAPSHOT</version>
   </dependency>
   </dependencies>
 </project>
diff --git a/algebricks/algebricks-examples/piglet-example/pom.xml b/algebricks/algebricks-examples/piglet-example/pom.xml
index 3c1588d..8297f4d 100644
--- a/algebricks/algebricks-examples/piglet-example/pom.xml
+++ b/algebricks/algebricks-examples/piglet-example/pom.xml
@@ -20,7 +20,7 @@
 	<parent>
 		<groupId>edu.uci.ics.hyracks</groupId>
 		<artifactId>algebricks-examples</artifactId>
-		<version>0.2.7-SNAPSHOT</version>
+		<version>0.2.10-SNAPSHOT</version>
 	</parent>
 
 	<build>
@@ -121,7 +121,7 @@
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>algebricks-compiler</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 		</dependency>
 		<dependency>
 			<groupId>junit</groupId>
diff --git a/algebricks/algebricks-examples/pom.xml b/algebricks/algebricks-examples/pom.xml
index 0376c13..31b7f2c 100644
--- a/algebricks/algebricks-examples/pom.xml
+++ b/algebricks/algebricks-examples/pom.xml
@@ -21,7 +21,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>algebricks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <modules>
diff --git a/algebricks/algebricks-rewriter/pom.xml b/algebricks/algebricks-rewriter/pom.xml
index d81a479..e66486f 100644
--- a/algebricks/algebricks-rewriter/pom.xml
+++ b/algebricks/algebricks-rewriter/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>algebricks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -41,7 +41,7 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>algebricks-core</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   	</dependency>
   </dependencies>
 </project>
diff --git a/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/EliminateGroupByEmptyKeyRule.java b/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/EliminateGroupByEmptyKeyRule.java
new file mode 100644
index 0000000..e93fdd1
--- /dev/null
+++ b/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/EliminateGroupByEmptyKeyRule.java
@@ -0,0 +1,86 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.algebricks.rewriter.rules;
+
+import java.util.List;
+
+import org.apache.commons.lang3.mutable.Mutable;
+
+import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalPlan;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.IOptimizationContext;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalOperatorTag;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalVariable;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.AbstractLogicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.GroupByOperator;
+import edu.uci.ics.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule;
+
+/**
+ * This rule lift out the aggregate operator out from a group-by operator
+ * if the gby operator groups-by on empty key, e.g., the group-by variables are empty.
+ * 
+ * @author yingyib
+ */
+public class EliminateGroupByEmptyKeyRule implements IAlgebraicRewriteRule {
+
+    @Override
+    public boolean rewritePre(Mutable<ILogicalOperator> opRef, IOptimizationContext context) throws AlgebricksException {
+        return false;
+    }
+
+    @Override
+    public boolean rewritePost(Mutable<ILogicalOperator> opRef, IOptimizationContext context)
+            throws AlgebricksException {
+        AbstractLogicalOperator op = (AbstractLogicalOperator) opRef.getValue();
+        if (op.getOperatorTag() != LogicalOperatorTag.GROUP) {
+            return false;
+        }
+        GroupByOperator groupOp = (GroupByOperator) op;
+        List<LogicalVariable> groupVars = groupOp.getGbyVarList();
+        if (groupVars.size() > 0) {
+            return false;
+        }
+        List<ILogicalPlan> nestedPlans = groupOp.getNestedPlans();
+        if (nestedPlans.size() > 1) {
+            return false;
+        }
+        ILogicalPlan nestedPlan = nestedPlans.get(0);
+        if (nestedPlan.getRoots().size() > 1) {
+            return false;
+        }
+        Mutable<ILogicalOperator> topOpRef = nestedPlan.getRoots().get(0);
+        ILogicalOperator topOp = nestedPlan.getRoots().get(0).getValue();
+        Mutable<ILogicalOperator> nestedTupleSourceRef = getNestedTupleSourceReference(topOpRef);
+        /**
+         * connect nested top op into the plan
+         */
+        opRef.setValue(topOp);
+        /**
+         * connect child op into the plan
+         */
+        nestedTupleSourceRef.setValue(groupOp.getInputs().get(0).getValue());
+        return true;
+    }
+
+    private Mutable<ILogicalOperator> getNestedTupleSourceReference(Mutable<ILogicalOperator> nestedTopOperatorRef) {
+        Mutable<ILogicalOperator> currentOpRef = nestedTopOperatorRef;
+        while (currentOpRef.getValue().getInputs() != null && currentOpRef.getValue().getInputs().size() > 0) {
+            currentOpRef = currentOpRef.getValue().getInputs().get(0);
+        }
+        return currentOpRef;
+    }
+
+}
diff --git a/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/EnforceStructuralPropertiesRule.java b/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/EnforceStructuralPropertiesRule.java
index 9292e07..98606f1 100644
--- a/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/EnforceStructuralPropertiesRule.java
+++ b/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/EnforceStructuralPropertiesRule.java
@@ -59,7 +59,7 @@
 import edu.uci.ics.hyracks.algebricks.core.algebra.operators.physical.StableSortPOperator;
 import edu.uci.ics.hyracks.algebricks.core.algebra.prettyprint.LogicalOperatorPrettyPrintVisitor;
 import edu.uci.ics.hyracks.algebricks.core.algebra.prettyprint.PlanPrettyPrinter;
-import edu.uci.ics.hyracks.algebricks.core.algebra.properties.AsterixNodeGroupDomain;
+import edu.uci.ics.hyracks.algebricks.core.algebra.properties.DefaultNodeGroupDomain;
 import edu.uci.ics.hyracks.algebricks.core.algebra.properties.FunctionalDependency;
 import edu.uci.ics.hyracks.algebricks.core.algebra.properties.ILocalStructuralProperty;
 import edu.uci.ics.hyracks.algebricks.core.algebra.properties.ILocalStructuralProperty.PropertyType;
@@ -85,7 +85,7 @@
 
 public class EnforceStructuralPropertiesRule implements IAlgebraicRewriteRule {
 
-    private static final INodeDomain DEFAULT_DOMAIN = new AsterixNodeGroupDomain("__DEFAULT");
+    private static final INodeDomain DEFAULT_DOMAIN = new DefaultNodeGroupDomain("__DEFAULT");
 
     private PhysicalOptimizationConfig physicalOptimizationConfig;
 
diff --git a/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/LeftOuterJoinToInnerJoinRule.java b/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/LeftOuterJoinToInnerJoinRule.java
new file mode 100644
index 0000000..247c10d
--- /dev/null
+++ b/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/LeftOuterJoinToInnerJoinRule.java
@@ -0,0 +1,118 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.algebricks.rewriter.rules;
+
+import org.apache.commons.lang3.mutable.Mutable;
+
+import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
+import edu.uci.ics.hyracks.algebricks.common.utils.ListSet;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.IOptimizationContext;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalExpressionTag;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalOperatorTag;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalVariable;
+import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.ScalarFunctionCallExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.VariableReferenceExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.functions.AlgebricksBuiltinFunctions;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.AbstractLogicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.InnerJoinOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.LeftOuterJoinOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.SelectOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.visitors.VariableUtilities;
+import edu.uci.ics.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule;
+
+/**
+ * This rule is to convert an outer join into an inner join when possible.
+ * 
+ * The specific pattern this rule will invoke for is:
+ * select not(is-null($v)) // $v is from the right branch of the left outer join below
+ *   left-outer-join
+ * 
+ * The pattern will be rewritten to:
+ * inner-join
+ * 
+ * @author yingyib
+ */
+public class LeftOuterJoinToInnerJoinRule implements IAlgebraicRewriteRule {
+
+    @Override
+    public boolean rewritePre(Mutable<ILogicalOperator> opRef, IOptimizationContext context) throws AlgebricksException {
+        return false;
+    }
+
+    @Override
+    public boolean rewritePost(Mutable<ILogicalOperator> opRef, IOptimizationContext context)
+            throws AlgebricksException {
+        AbstractLogicalOperator op = (AbstractLogicalOperator) opRef.getValue();
+        if (op.getOperatorTag() != LogicalOperatorTag.SELECT) {
+            return false;
+        }
+        Mutable<ILogicalOperator> op2Ref = op.getInputs().get(0);
+        AbstractLogicalOperator op2 = (AbstractLogicalOperator) op2Ref.getValue();
+        if (op2.getOperatorTag() != LogicalOperatorTag.LEFTOUTERJOIN) {
+            return false;
+        }
+        SelectOperator selectOp = (SelectOperator) op;
+        LeftOuterJoinOperator joinOp = (LeftOuterJoinOperator) op2;
+        ILogicalExpression condition = selectOp.getCondition().getValue();
+        if (condition.getExpressionTag() != LogicalExpressionTag.FUNCTION_CALL) {
+            return false;
+        }
+        ScalarFunctionCallExpression func = (ScalarFunctionCallExpression) condition;
+        /** check if the filter condition on top of the LOJ is not(is-null($v)), where $v is from the right child of LOJ */
+        if (!convertable(func, joinOp)) {
+            return false;
+        }
+        ILogicalOperator newJoin = new InnerJoinOperator(joinOp.getCondition(), joinOp.getInputs().get(0), joinOp
+                .getInputs().get(1));
+        opRef.setValue(newJoin);
+        context.computeAndSetTypeEnvironmentForOperator(newJoin);
+        return true;
+    }
+
+    /**
+     * check if the condition is not(is-null(var)) and var is from the right branch of the join
+     */
+    private boolean convertable(ScalarFunctionCallExpression func, LeftOuterJoinOperator join)
+            throws AlgebricksException {
+        if (func.getFunctionIdentifier() != AlgebricksBuiltinFunctions.NOT) {
+            return false;
+        }
+        ILogicalExpression arg = func.getArguments().get(0).getValue();
+        if (arg.getExpressionTag() != LogicalExpressionTag.FUNCTION_CALL) {
+            return false;
+        }
+        ScalarFunctionCallExpression func2 = (ScalarFunctionCallExpression) arg;
+        if (func2.getFunctionIdentifier() != AlgebricksBuiltinFunctions.IS_NULL) {
+            return false;
+        }
+        ILogicalExpression arg2 = func2.getArguments().get(0).getValue();
+        if (arg2.getExpressionTag() != LogicalExpressionTag.VARIABLE) {
+            return false;
+        }
+        VariableReferenceExpression varExpr = (VariableReferenceExpression) arg2;
+        LogicalVariable var = varExpr.getVariableReference();
+        ListSet<LogicalVariable> leftVars = new ListSet<LogicalVariable>();
+        ListSet<LogicalVariable> rightVars = new ListSet<LogicalVariable>();
+        VariableUtilities.getLiveVariables(join.getInputs().get(0).getValue(), leftVars);
+        VariableUtilities.getLiveVariables(join.getInputs().get(1).getValue(), rightVars);
+        if (!rightVars.contains(var)) {
+            return false;
+        }
+        return true;
+    }
+
+}
diff --git a/algebricks/algebricks-runtime/pom.xml b/algebricks/algebricks-runtime/pom.xml
index 31b25be..570afb4 100644
--- a/algebricks/algebricks-runtime/pom.xml
+++ b/algebricks/algebricks-runtime/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>algebricks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -41,27 +41,27 @@
   <dependency>
   	<groupId>edu.uci.ics.hyracks</groupId>
   	<artifactId>hyracks-storage-am-btree</artifactId>
-  	<version>0.2.7-SNAPSHOT</version>
+  	<version>0.2.10-SNAPSHOT</version>
   </dependency>
   <dependency>
   	<groupId>edu.uci.ics.hyracks</groupId>
   	<artifactId>hyracks-storage-am-rtree</artifactId>
-  	<version>0.2.7-SNAPSHOT</version>
+  	<version>0.2.10-SNAPSHOT</version>
   </dependency>
   <dependency>
   	<groupId>edu.uci.ics.hyracks</groupId>
   	<artifactId>hyracks-dataflow-std</artifactId>
-  	<version>0.2.7-SNAPSHOT</version>
+  	<version>0.2.10-SNAPSHOT</version>
   </dependency>
   <dependency>
   	<groupId>edu.uci.ics.hyracks</groupId>
   	<artifactId>algebricks-common</artifactId>
-  	<version>0.2.7-SNAPSHOT</version>
+  	<version>0.2.10-SNAPSHOT</version>
   </dependency>
   <dependency>
   	<groupId>edu.uci.ics.hyracks</groupId>
   	<artifactId>algebricks-data</artifactId>
-  	<version>0.2.7-SNAPSHOT</version>
+  	<version>0.2.10-SNAPSHOT</version>
   </dependency>
   </dependencies>
 </project>
diff --git a/algebricks/algebricks-runtime/src/main/java/edu/uci/ics/hyracks/algebricks/runtime/operators/base/AbstractOneInputOneOutputOneFramePushRuntime.java b/algebricks/algebricks-runtime/src/main/java/edu/uci/ics/hyracks/algebricks/runtime/operators/base/AbstractOneInputOneOutputOneFramePushRuntime.java
index 082e98a..6c1dd5e 100644
--- a/algebricks/algebricks-runtime/src/main/java/edu/uci/ics/hyracks/algebricks/runtime/operators/base/AbstractOneInputOneOutputOneFramePushRuntime.java
+++ b/algebricks/algebricks-runtime/src/main/java/edu/uci/ics/hyracks/algebricks/runtime/operators/base/AbstractOneInputOneOutputOneFramePushRuntime.java
@@ -43,6 +43,10 @@
     }
 
     protected void appendToFrameFromTupleBuilder(ArrayTupleBuilder tb) throws HyracksDataException {
+        appendToFrameFromTupleBuilder(tb, false);
+    }
+
+    protected void appendToFrameFromTupleBuilder(ArrayTupleBuilder tb, boolean flushFrame) throws HyracksDataException {
         if (!appender.append(tb.getFieldEndOffsets(), tb.getByteArray(), 0, tb.getSize())) {
             FrameUtils.flushFrame(frame, writer);
             appender.reset(frame, true);
@@ -51,6 +55,10 @@
                         "Could not write frame (AbstractOneInputOneOutputOneFramePushRuntime.appendToFrameFromTupleBuilder).");
             }
         }
+        if (flushFrame) {
+            FrameUtils.flushFrame(frame, writer);
+            appender.reset(frame, true);
+        }
     }
 
     protected void appendProjectionToFrame(int tIndex, int[] projectionList) throws HyracksDataException {
diff --git a/algebricks/algebricks-runtime/src/main/java/edu/uci/ics/hyracks/algebricks/runtime/operators/std/AssignRuntimeFactory.java b/algebricks/algebricks-runtime/src/main/java/edu/uci/ics/hyracks/algebricks/runtime/operators/std/AssignRuntimeFactory.java
index fa99c15..fb889ea 100644
--- a/algebricks/algebricks-runtime/src/main/java/edu/uci/ics/hyracks/algebricks/runtime/operators/std/AssignRuntimeFactory.java
+++ b/algebricks/algebricks-runtime/src/main/java/edu/uci/ics/hyracks/algebricks/runtime/operators/std/AssignRuntimeFactory.java
@@ -36,6 +36,7 @@
 
     private int[] outColumns;
     private IScalarEvaluatorFactory[] evalFactories;
+    private final boolean flushFramesRapidly;
 
     /**
      * @param outColumns
@@ -46,9 +47,15 @@
      */
 
     public AssignRuntimeFactory(int[] outColumns, IScalarEvaluatorFactory[] evalFactories, int[] projectionList) {
+        this(outColumns, evalFactories, projectionList, false);
+    }
+
+    public AssignRuntimeFactory(int[] outColumns, IScalarEvaluatorFactory[] evalFactories, int[] projectionList,
+            boolean flushFramesRapidly) {
         super(projectionList);
         this.outColumns = outColumns;
         this.evalFactories = evalFactories;
+        this.flushFramesRapidly = flushFramesRapidly;
     }
 
     @Override
@@ -107,9 +114,22 @@
             public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
                 tAccess.reset(buffer);
                 int nTuple = tAccess.getTupleCount();
-                for (int t = 0; t < nTuple; t++) {
-                    tRef.reset(tAccess, t);
-                    produceTuple(tupleBuilder, tAccess, t, tRef);
+                int t = 0;
+                if (nTuple > 1) {
+                    for (; t < nTuple - 1; t++) {
+                        tRef.reset(tAccess, t);
+                        produceTuple(tupleBuilder, tAccess, t, tRef);
+                        appendToFrameFromTupleBuilder(tupleBuilder);
+                    }
+                }
+
+                tRef.reset(tAccess, t);
+                produceTuple(tupleBuilder, tAccess, t, tRef);
+                if (flushFramesRapidly) {
+                    // Whenever all the tuples in the incoming frame have been consumed, the assign operator 
+                    // will push its frame to the next operator; i.e., it won't wait until the frame gets full. 
+                    appendToFrameFromTupleBuilder(tupleBuilder, true);
+                } else {
                     appendToFrameFromTupleBuilder(tupleBuilder);
                 }
             }
diff --git a/algebricks/algebricks-runtime/src/main/java/edu/uci/ics/hyracks/algebricks/runtime/operators/std/StreamProjectRuntimeFactory.java b/algebricks/algebricks-runtime/src/main/java/edu/uci/ics/hyracks/algebricks/runtime/operators/std/StreamProjectRuntimeFactory.java
index 7f10948..3e87f31 100644
--- a/algebricks/algebricks-runtime/src/main/java/edu/uci/ics/hyracks/algebricks/runtime/operators/std/StreamProjectRuntimeFactory.java
+++ b/algebricks/algebricks-runtime/src/main/java/edu/uci/ics/hyracks/algebricks/runtime/operators/std/StreamProjectRuntimeFactory.java
@@ -34,8 +34,7 @@
     }
 
     public StreamProjectRuntimeFactory(int[] projectionList) {
-        super(projectionList);
-        this.flushFramesRapidly = false;
+        this(projectionList, false);
     }
 
     @Override
@@ -66,8 +65,10 @@
                 int nTuple = tAccess.getTupleCount();
 
                 int t = 0;
-                for (; t < nTuple - 1; t++) {
-                    appendProjectionToFrame(t, projectionList);
+                if (nTuple > 1) {
+                    for (; t < nTuple - 1; t++) {
+                        appendProjectionToFrame(t, projectionList);
+                    }
                 }
                 if (flushFramesRapidly) {
                     // Whenever all the tuples in the incoming frame have been consumed, the project operator 
@@ -76,10 +77,8 @@
                 } else {
                     appendProjectionToFrame(t, projectionList);
                 }
-
             }
 
         };
     }
-
 }
diff --git a/algebricks/algebricks-tests/pom.xml b/algebricks/algebricks-tests/pom.xml
index 271083d..4d7abad 100644
--- a/algebricks/algebricks-tests/pom.xml
+++ b/algebricks/algebricks-tests/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>algebricks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -99,7 +99,7 @@
   <dependency>
   	<groupId>edu.uci.ics.hyracks</groupId>
   	<artifactId>algebricks-compiler</artifactId>
-  	<version>0.2.7-SNAPSHOT</version>
+  	<version>0.2.10-SNAPSHOT</version>
   </dependency>
   <dependency>
   	<groupId>junit</groupId>
@@ -110,17 +110,17 @@
   <dependency>
   	<groupId>edu.uci.ics.hyracks</groupId>
   	<artifactId>hyracks-control-cc</artifactId>
-  	<version>0.2.7-SNAPSHOT</version>
+  	<version>0.2.10-SNAPSHOT</version>
   </dependency>
   <dependency>
   	<groupId>edu.uci.ics.hyracks</groupId>
   	<artifactId>hyracks-control-nc</artifactId>
-  	<version>0.2.7-SNAPSHOT</version>
+  	<version>0.2.10-SNAPSHOT</version>
   </dependency>
   <dependency>
   	<groupId>edu.uci.ics.hyracks</groupId>
   	<artifactId>hyracks-data-std</artifactId>
-  	<version>0.2.7-SNAPSHOT</version>
+  	<version>0.2.10-SNAPSHOT</version>
   </dependency>
   </dependencies>
 </project>
diff --git a/algebricks/pom.xml b/algebricks/pom.xml
index 774b07d..427e29b 100644
--- a/algebricks/pom.xml
+++ b/algebricks/pom.xml
@@ -16,7 +16,7 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>edu.uci.ics.hyracks</groupId>
   <artifactId>algebricks</artifactId>
-  <version>0.2.7-SNAPSHOT</version>
+  <version>0.2.10-SNAPSHOT</version>
   <packaging>pom</packaging>
   <name>algebricks</name>
 
diff --git a/hivesterix/build.sh b/hivesterix/build.sh
new file mode 100644
index 0000000..8f61559
--- /dev/null
+++ b/hivesterix/build.sh
@@ -0,0 +1,12 @@
+rm -rf dist
+mkdir dist
+
+hadoop_versions=(0.20.2 0.23.1 0.23.6 1.0.4 cdh-4.1 cdh-4.2)
+cd ../
+for v in ${hadoop_versions[@]}
+do
+   #echo mvn clean package -DskipTests=true -Dhadoop=${v}
+   mvn clean package -DskipTests=true -Dhadoop=${v}
+   #echo mv hivesterix/hivesterix-dist/target/hivesterix-dist-*-binary-assembly.zip hivesterix/dist/hivesterix-dist-binary-assembley-hdfs-${v}.zip
+   mv hivesterix/hivesterix-dist/target/hivesterix-dist-*-binary-assembly.zip hivesterix/dist/hivesterix-dist-binary-assembley-hdfs-${v}.zip
+done
diff --git a/hivesterix/hivesterix-common/pom.xml b/hivesterix/hivesterix-common/pom.xml
index 7741193..fe9271b 100644
--- a/hivesterix/hivesterix-common/pom.xml
+++ b/hivesterix/hivesterix-common/pom.xml
@@ -1,18 +1,13 @@
 <?xml version="1.0"?>
-<!--
- ! Copyright 2009-2013 by The Regents of the University of California
- ! Licensed under the Apache License, Version 2.0 (the "License");
- ! you may not use this file except in compliance with the License.
- ! you may obtain a copy of the License from
- ! 
- !     http://www.apache.org/licenses/LICENSE-2.0
- ! 
- ! Unless required by applicable law or agreed to in writing, software
- ! distributed under the License is distributed on an "AS IS" BASIS,
- ! WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- ! See the License for the specific language governing permissions and
- ! limitations under the License.
- !-->
+<!-- ! Copyright 2009-2013 by The Regents of the University of California 
+	! Licensed under the Apache License, Version 2.0 (the "License"); ! you may 
+	not use this file except in compliance with the License. ! you may obtain 
+	a copy of the License from ! ! http://www.apache.org/licenses/LICENSE-2.0 
+	! ! Unless required by applicable law or agreed to in writing, software ! 
+	distributed under the License is distributed on an "AS IS" BASIS, ! WITHOUT 
+	WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. ! See the 
+	License for the specific language governing permissions and ! limitations 
+	under the License. ! -->
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<artifactId>hivesterix-common</artifactId>
@@ -21,7 +16,7 @@
 	<parent>
 		<artifactId>hivesterix</artifactId>
 		<groupId>edu.uci.ics.hyracks</groupId>
-		<version>0.2.7-SNAPSHOT</version>
+		<version>0.2.10-SNAPSHOT</version>
 	</parent>
 
 	<build>
@@ -44,30 +39,54 @@
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-api</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>algebricks-compiler</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-hdfs-core</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
-			<groupId>org.apache.hadoop.hive</groupId>
+			<groupId>org.apache.hive</groupId>
 			<artifactId>hive-exec</artifactId>
-			<version>0.7.0</version>
+			<version>0.11.0</version>
+			<type>jar</type>
+			<scope>compile</scope>
+		</dependency>
+		<dependency>
+			<groupId>edu.uci.ics.hyracks</groupId>
+			<artifactId>hivesterix-serde</artifactId>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 	</dependencies>
+
+	<repositories>
+		<repository>
+			<releases>
+				<enabled>true</enabled>
+				<updatePolicy>always</updatePolicy>
+				<checksumPolicy>warn</checksumPolicy>
+			</releases>
+			<snapshots>
+				<enabled>true</enabled>
+				<updatePolicy>always</updatePolicy>
+				<checksumPolicy>fail</checksumPolicy>
+			</snapshots>
+			<id>cdh-build</id>
+			<url>https://repository.cloudera.com/content/groups/cdh-build</url>
+		</repository>
+	</repositories>
 </project>
diff --git a/hivesterix/hivesterix-common/src/main/java/edu/uci/ics/hivesterix/logical/expression/ExpressionTranslator.java b/hivesterix/hivesterix-common/src/main/java/edu/uci/ics/hivesterix/logical/expression/ExpressionTranslator.java
index 783004c..2ec3811 100644
--- a/hivesterix/hivesterix-common/src/main/java/edu/uci/ics/hivesterix/logical/expression/ExpressionTranslator.java
+++ b/hivesterix/hivesterix-common/src/main/java/edu/uci/ics/hivesterix/logical/expression/ExpressionTranslator.java
@@ -12,212 +12,217 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package edu.uci.ics.hivesterix.logical.expression;
-
-import java.util.ArrayList;
-import java.util.List;
-
-import org.apache.commons.lang3.mutable.Mutable;
-import org.apache.hadoop.hive.ql.exec.FunctionInfo;
-import org.apache.hadoop.hive.ql.exec.FunctionRegistry;
-import org.apache.hadoop.hive.ql.plan.AggregationDesc;
-import org.apache.hadoop.hive.ql.plan.ExprNodeColumnDesc;
-import org.apache.hadoop.hive.ql.plan.ExprNodeConstantDesc;
-import org.apache.hadoop.hive.ql.plan.ExprNodeDesc;
-import org.apache.hadoop.hive.ql.plan.ExprNodeFieldDesc;
-import org.apache.hadoop.hive.ql.plan.ExprNodeGenericFuncDesc;
-import org.apache.hadoop.hive.ql.plan.ExprNodeNullDesc;
-import org.apache.hadoop.hive.ql.plan.UDTFDesc;
-import org.apache.hadoop.hive.ql.udf.generic.GenericUDAFEvaluator;
-import org.apache.hadoop.hive.ql.udf.generic.GenericUDF;
-import org.apache.hadoop.hive.ql.udf.generic.GenericUDTF;
-import org.apache.hadoop.hive.serde2.typeinfo.StructTypeInfo;
-import org.apache.hadoop.hive.serde2.typeinfo.TypeInfo;
-import org.apache.hadoop.hive.serde2.typeinfo.TypeInfoFactory;
-
-import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
-import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalExpression;
-import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalExpressionTag;
-import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalVariable;
-import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.AbstractFunctionCallExpression;
-import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.AggregateFunctionCallExpression;
-import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.ConstantExpression;
-import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.IVariableTypeEnvironment;
-import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.ScalarFunctionCallExpression;
-import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.UnnestingFunctionCallExpression;
-import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.VariableReferenceExpression;
-import edu.uci.ics.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
-import edu.uci.ics.hyracks.algebricks.core.algebra.functions.IFunctionInfo;
-
-public class ExpressionTranslator {
-
-    public static Object getHiveExpression(ILogicalExpression expr, IVariableTypeEnvironment env) throws Exception {
-        if (expr.getExpressionTag() == LogicalExpressionTag.FUNCTION_CALL) {
-            /**
-             * function expression
-             */
-            AbstractFunctionCallExpression funcExpr = (AbstractFunctionCallExpression) expr;
-            IFunctionInfo funcInfo = funcExpr.getFunctionInfo();
-            FunctionIdentifier fid = funcInfo.getFunctionIdentifier();
-
-            if (fid.getName().equals(ExpressionConstant.FIELDACCESS)) {
-                Object info = ((HiveFunctionInfo) funcInfo).getInfo();
-                ExprNodeFieldDesc desc = (ExprNodeFieldDesc) info;
-                return new ExprNodeFieldDesc(desc.getTypeInfo(), desc.getDesc(), desc.getFieldName(), desc.getIsList());
-            }
-
-            if (fid.getName().equals(ExpressionConstant.NULL)) {
-                return new ExprNodeNullDesc();
-            }
-
-            /**
-             * argument expressions: translate argument expressions recursively
-             * first, this logic is shared in scalar, aggregation and unnesting
-             * function
-             */
-            List<Mutable<ILogicalExpression>> arguments = funcExpr.getArguments();
-            List<ExprNodeDesc> parameters = new ArrayList<ExprNodeDesc>();
-            for (Mutable<ILogicalExpression> argument : arguments) {
-                /**
-                 * parameters could not be aggregate function desc
-                 */
-                ExprNodeDesc parameter = (ExprNodeDesc) getHiveExpression(argument.getValue(), env);
-                parameters.add(parameter);
-            }
-
-            /**
-             * get expression
-             */
-            if (funcExpr instanceof ScalarFunctionCallExpression) {
-                String udfName = HiveAlgebricksBuiltInFunctionMap.INSTANCE.getHiveFunctionName(fid);
-                GenericUDF udf;
-                if (udfName != null) {
-                    /**
-                     * get corresponding function info for built-in functions
-                     */
-                    FunctionInfo fInfo = FunctionRegistry.getFunctionInfo(udfName);
-                    udf = fInfo.getGenericUDF();
-
-                    int inputSize = parameters.size();
-                    List<ExprNodeDesc> currentDescs = new ArrayList<ExprNodeDesc>();
-
-                    // generate expression tree if necessary
-                    while (inputSize > 2) {
-                        int pairs = inputSize / 2;
-                        for (int i = 0; i < pairs; i++) {
-                            List<ExprNodeDesc> descs = new ArrayList<ExprNodeDesc>();
-                            descs.add(parameters.get(2 * i));
-                            descs.add(parameters.get(2 * i + 1));
-                            ExprNodeDesc desc = ExprNodeGenericFuncDesc.newInstance(udf, descs);
-                            currentDescs.add(desc);
-                        }
-
-                        if (inputSize % 2 != 0) {
-                            // List<ExprNodeDesc> descs = new
-                            // ArrayList<ExprNodeDesc>();
-                            // ExprNodeDesc lastExpr =
-                            // currentDescs.remove(currentDescs.size() - 1);
-                            // descs.add(lastExpr);
-                            currentDescs.add(parameters.get(inputSize - 1));
-                            // ExprNodeDesc desc =
-                            // ExprNodeGenericFuncDesc.newInstance(udf, descs);
-                            // currentDescs.add(desc);
-                        }
-                        inputSize = currentDescs.size();
-                        parameters.clear();
-                        parameters.addAll(currentDescs);
-                        currentDescs.clear();
-                    }
-
-                } else {
-                    Object secondInfo = ((HiveFunctionInfo) funcInfo).getInfo();
-                    if (secondInfo != null) {
-
-                        /**
-                         * for GenericUDFBridge: we should not call get type of
-                         * this hive expression, because parameters may have
-                         * been changed!
-                         */
-                        ExprNodeGenericFuncDesc hiveExpr = (ExprNodeGenericFuncDesc) ((HiveFunctionInfo) funcInfo)
-                                .getInfo();
-                        udf = hiveExpr.getGenericUDF();
-                    } else {
-                        /**
-                         * for other generic UDF
-                         */
-                        Class<?> udfClass;
-                        try {
-                            udfClass = Class.forName(fid.getName());
-                            udf = (GenericUDF) udfClass.newInstance();
-                        } catch (Exception e) {
-                            e.printStackTrace();
-                            throw new AlgebricksException(e.getMessage());
-                        }
-                    }
-                }
-                /**
-                 * get hive generic function expression
-                 */
-                ExprNodeDesc desc = ExprNodeGenericFuncDesc.newInstance(udf, parameters);
-                return desc;
-            } else if (funcExpr instanceof AggregateFunctionCallExpression) {
-                /**
-                 * hive aggregation info
-                 */
-                AggregationDesc aggregateDesc = (AggregationDesc) ((HiveFunctionInfo) funcExpr.getFunctionInfo())
-                        .getInfo();
-                /**
-                 * set parameters
-                 */
-                aggregateDesc.setParameters((ArrayList<ExprNodeDesc>) parameters);
-
-                List<TypeInfo> originalParameterTypeInfos = new ArrayList<TypeInfo>();
-                for (ExprNodeDesc parameter : parameters) {
-                    if (parameter.getTypeInfo() instanceof StructTypeInfo) {
-                        originalParameterTypeInfos.add(TypeInfoFactory.doubleTypeInfo);
-                    } else
-                        originalParameterTypeInfos.add(parameter.getTypeInfo());
-                }
-
-                GenericUDAFEvaluator eval = FunctionRegistry.getGenericUDAFEvaluator(
-                        aggregateDesc.getGenericUDAFName(), originalParameterTypeInfos, aggregateDesc.getDistinct(),
-                        false);
-
-                AggregationDesc newAggregateDesc = new AggregationDesc(aggregateDesc.getGenericUDAFName(), eval,
-                        aggregateDesc.getParameters(), aggregateDesc.getDistinct(), aggregateDesc.getMode());
-                return newAggregateDesc;
-            } else if (funcExpr instanceof UnnestingFunctionCallExpression) {
-                /**
-                 * type inference for UDTF function
-                 */
-                UDTFDesc hiveDesc = (UDTFDesc) ((HiveFunctionInfo) funcExpr.getFunctionInfo()).getInfo();
-                String funcName = hiveDesc.getUDTFName();
-                FunctionInfo fi = FunctionRegistry.getFunctionInfo(funcName);
-                GenericUDTF udtf = fi.getGenericUDTF();
-                UDTFDesc desc = new UDTFDesc(udtf);
-                return desc;
-            } else {
-                throw new IllegalStateException("unrecognized function expression " + expr.getClass().getName());
-            }
-        } else if ((expr.getExpressionTag() == LogicalExpressionTag.VARIABLE)) {
-            /**
-             * get type for variable in the environment
-             */
-            VariableReferenceExpression varExpr = (VariableReferenceExpression) expr;
-            LogicalVariable var = varExpr.getVariableReference();
-            TypeInfo typeInfo = (TypeInfo) env.getVarType(var);
-            ExprNodeDesc desc = new ExprNodeColumnDesc(typeInfo, var.toString(), "", false);
-            return desc;
-        } else if ((expr.getExpressionTag() == LogicalExpressionTag.CONSTANT)) {
-            /**
-             * get expression for constant in the environment
-             */
-            ConstantExpression varExpr = (ConstantExpression) expr;
-            Object value = ((HivesterixConstantValue) varExpr.getValue()).getObject();
-            ExprNodeDesc desc = new ExprNodeConstantDesc(value);
-            return desc;
-        } else {
-            throw new IllegalStateException("illegal expressions " + expr.getClass().getName());
-        }
-    }
-}
+package edu.uci.ics.hivesterix.logical.expression;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.commons.lang3.mutable.Mutable;
+import org.apache.hadoop.hive.ql.exec.FunctionInfo;
+import org.apache.hadoop.hive.ql.exec.FunctionRegistry;
+import org.apache.hadoop.hive.ql.plan.AggregationDesc;
+import org.apache.hadoop.hive.ql.plan.ExprNodeColumnDesc;
+import org.apache.hadoop.hive.ql.plan.ExprNodeConstantDesc;
+import org.apache.hadoop.hive.ql.plan.ExprNodeDesc;
+import org.apache.hadoop.hive.ql.plan.ExprNodeFieldDesc;
+import org.apache.hadoop.hive.ql.plan.ExprNodeGenericFuncDesc;
+import org.apache.hadoop.hive.ql.plan.ExprNodeNullDesc;
+import org.apache.hadoop.hive.ql.plan.UDTFDesc;
+import org.apache.hadoop.hive.ql.udf.generic.GenericUDAFEvaluator;
+import org.apache.hadoop.hive.ql.udf.generic.GenericUDF;
+import org.apache.hadoop.hive.ql.udf.generic.GenericUDTF;
+import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
+import org.apache.hadoop.hive.serde2.typeinfo.StructTypeInfo;
+import org.apache.hadoop.hive.serde2.typeinfo.TypeInfo;
+import org.apache.hadoop.hive.serde2.typeinfo.TypeInfoFactory;
+
+import edu.uci.ics.hivesterix.serde.lazy.LazyUtils;
+import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalExpressionTag;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalVariable;
+import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.AbstractFunctionCallExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.AggregateFunctionCallExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.ConstantExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.IVariableTypeEnvironment;
+import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.ScalarFunctionCallExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.UnnestingFunctionCallExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.VariableReferenceExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
+import edu.uci.ics.hyracks.algebricks.core.algebra.functions.IFunctionInfo;
+
+public class ExpressionTranslator {
+
+    public static Object getHiveExpression(ILogicalExpression expr, IVariableTypeEnvironment env) throws Exception {
+        if (expr.getExpressionTag() == LogicalExpressionTag.FUNCTION_CALL) {
+            /**
+             * function expression
+             */
+            AbstractFunctionCallExpression funcExpr = (AbstractFunctionCallExpression) expr;
+            IFunctionInfo funcInfo = funcExpr.getFunctionInfo();
+            FunctionIdentifier fid = funcInfo.getFunctionIdentifier();
+
+            if (fid.getName().equals(ExpressionConstant.FIELDACCESS)) {
+                Object info = ((HiveFunctionInfo) funcInfo).getInfo();
+                ExprNodeFieldDesc desc = (ExprNodeFieldDesc) info;
+                return new ExprNodeFieldDesc(desc.getTypeInfo(), desc.getDesc(), desc.getFieldName(), desc.getIsList());
+            }
+
+            if (fid.getName().equals(ExpressionConstant.NULL)) {
+                return new ExprNodeNullDesc();
+            }
+
+            /**
+             * argument expressions: translate argument expressions recursively
+             * first, this logic is shared in scalar, aggregation and unnesting
+             * function
+             */
+            List<Mutable<ILogicalExpression>> arguments = funcExpr.getArguments();
+            List<ExprNodeDesc> parameters = new ArrayList<ExprNodeDesc>();
+            for (Mutable<ILogicalExpression> argument : arguments) {
+                /**
+                 * parameters could not be aggregate function desc
+                 */
+                ExprNodeDesc parameter = (ExprNodeDesc) getHiveExpression(argument.getValue(), env);
+                parameters.add(parameter);
+            }
+
+            /**
+             * get expression
+             */
+            if (funcExpr instanceof ScalarFunctionCallExpression) {
+                String udfName = HiveAlgebricksBuiltInFunctionMap.INSTANCE.getHiveFunctionName(fid);
+                GenericUDF udf;
+                if (udfName != null) {
+                    /**
+                     * get corresponding function info for built-in functions
+                     */
+                    FunctionInfo fInfo = FunctionRegistry.getFunctionInfo(udfName);
+                    udf = fInfo.getGenericUDF();
+
+                    int inputSize = parameters.size();
+                    List<ExprNodeDesc> currentDescs = new ArrayList<ExprNodeDesc>();
+
+                    // generate expression tree if necessary
+                    while (inputSize > 2) {
+                        int pairs = inputSize / 2;
+                        for (int i = 0; i < pairs; i++) {
+                            List<ExprNodeDesc> descs = new ArrayList<ExprNodeDesc>();
+                            descs.add(parameters.get(2 * i));
+                            descs.add(parameters.get(2 * i + 1));
+                            ExprNodeDesc desc = ExprNodeGenericFuncDesc.newInstance(udf, descs);
+                            currentDescs.add(desc);
+                        }
+
+                        if (inputSize % 2 != 0) {
+                            // List<ExprNodeDesc> descs = new
+                            // ArrayList<ExprNodeDesc>();
+                            // ExprNodeDesc lastExpr =
+                            // currentDescs.remove(currentDescs.size() - 1);
+                            // descs.add(lastExpr);
+                            currentDescs.add(parameters.get(inputSize - 1));
+                            // ExprNodeDesc desc =
+                            // ExprNodeGenericFuncDesc.newInstance(udf, descs);
+                            // currentDescs.add(desc);
+                        }
+                        inputSize = currentDescs.size();
+                        parameters.clear();
+                        parameters.addAll(currentDescs);
+                        currentDescs.clear();
+                    }
+
+                } else {
+                    Object secondInfo = ((HiveFunctionInfo) funcInfo).getInfo();
+                    if (secondInfo != null) {
+
+                        /**
+                         * for GenericUDFBridge: we should not call get type of
+                         * this hive expression, because parameters may have
+                         * been changed!
+                         */
+                        ExprNodeGenericFuncDesc hiveExpr = (ExprNodeGenericFuncDesc) ((HiveFunctionInfo) funcInfo)
+                                .getInfo();
+                        udf = hiveExpr.getGenericUDF();
+                    } else {
+                        /**
+                         * for other generic UDF
+                         */
+                        Class<?> udfClass;
+                        try {
+                            udfClass = Class.forName(fid.getName());
+                            udf = (GenericUDF) udfClass.newInstance();
+                        } catch (Exception e) {
+                            e.printStackTrace();
+                            throw new AlgebricksException(e.getMessage());
+                        }
+                    }
+                }
+                /**
+                 * get hive generic function expression
+                 */
+                ExprNodeDesc desc = ExprNodeGenericFuncDesc.newInstance(udf, parameters);
+                return desc;
+            } else if (funcExpr instanceof AggregateFunctionCallExpression) {
+                /**
+                 * hive aggregation info
+                 */
+                AggregationDesc aggregateDesc = (AggregationDesc) ((HiveFunctionInfo) funcExpr.getFunctionInfo())
+                        .getInfo();
+                /**
+                 * set parameters
+                 */
+                aggregateDesc.setParameters((ArrayList<ExprNodeDesc>) parameters);
+
+                List<TypeInfo> originalParameterTypeInfos = new ArrayList<TypeInfo>();
+                for (ExprNodeDesc parameter : parameters) {
+                    if (parameter.getTypeInfo() instanceof StructTypeInfo) {
+                        originalParameterTypeInfos.add(TypeInfoFactory.doubleTypeInfo);
+                    } else
+                        originalParameterTypeInfos.add(parameter.getTypeInfo());
+                }
+
+                List<ObjectInspector> originalParameterOIs = new ArrayList<ObjectInspector>();
+                for (TypeInfo type : originalParameterTypeInfos) {
+                    originalParameterOIs.add(LazyUtils.getLazyObjectInspectorFromTypeInfo(type, false));
+                }
+                GenericUDAFEvaluator eval = FunctionRegistry.getGenericUDAFEvaluator(
+                        aggregateDesc.getGenericUDAFName(), originalParameterOIs, aggregateDesc.getDistinct(), false);
+
+                AggregationDesc newAggregateDesc = new AggregationDesc(aggregateDesc.getGenericUDAFName(), eval,
+                        aggregateDesc.getParameters(), aggregateDesc.getDistinct(), aggregateDesc.getMode());
+                return newAggregateDesc;
+            } else if (funcExpr instanceof UnnestingFunctionCallExpression) {
+                /**
+                 * type inference for UDTF function
+                 */
+                UDTFDesc hiveDesc = (UDTFDesc) ((HiveFunctionInfo) funcExpr.getFunctionInfo()).getInfo();
+                String funcName = hiveDesc.getUDTFName();
+                FunctionInfo fi = FunctionRegistry.getFunctionInfo(funcName);
+                GenericUDTF udtf = fi.getGenericUDTF();
+                UDTFDesc desc = new UDTFDesc(udtf);
+                return desc;
+            } else {
+                throw new IllegalStateException("unrecognized function expression " + expr.getClass().getName());
+            }
+        } else if ((expr.getExpressionTag() == LogicalExpressionTag.VARIABLE)) {
+            /**
+             * get type for variable in the environment
+             */
+            VariableReferenceExpression varExpr = (VariableReferenceExpression) expr;
+            LogicalVariable var = varExpr.getVariableReference();
+            TypeInfo typeInfo = (TypeInfo) env.getVarType(var);
+            ExprNodeDesc desc = new ExprNodeColumnDesc(typeInfo, var.toString(), "", false);
+            return desc;
+        } else if ((expr.getExpressionTag() == LogicalExpressionTag.CONSTANT)) {
+            /**
+             * get expression for constant in the environment
+             */
+            ConstantExpression varExpr = (ConstantExpression) expr;
+            Object value = ((HivesterixConstantValue) varExpr.getValue()).getObject();
+            ExprNodeDesc desc = new ExprNodeConstantDesc(value);
+            return desc;
+        } else {
+            throw new IllegalStateException("illegal expressions " + expr.getClass().getName());
+        }
+    }
+}
diff --git a/hivesterix/hivesterix-dist/pom.xml b/hivesterix/hivesterix-dist/pom.xml
index 8ecdfe1..917487f 100644
--- a/hivesterix/hivesterix-dist/pom.xml
+++ b/hivesterix/hivesterix-dist/pom.xml
@@ -1,27 +1,22 @@
-<!--
- ! Copyright 2009-2013 by The Regents of the University of California
- ! Licensed under the Apache License, Version 2.0 (the "License");
- ! you may not use this file except in compliance with the License.
- ! you may obtain a copy of the License from
- ! 
- !     http://www.apache.org/licenses/LICENSE-2.0
- ! 
- ! Unless required by applicable law or agreed to in writing, software
- ! distributed under the License is distributed on an "AS IS" BASIS,
- ! WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- ! See the License for the specific language governing permissions and
- ! limitations under the License.
- !-->
+<!-- ! Copyright 2009-2013 by The Regents of the University of California 
+	! Licensed under the Apache License, Version 2.0 (the "License"); ! you may 
+	not use this file except in compliance with the License. ! you may obtain 
+	a copy of the License from ! ! http://www.apache.org/licenses/LICENSE-2.0 
+	! ! Unless required by applicable law or agreed to in writing, software ! 
+	distributed under the License is distributed on an "AS IS" BASIS, ! WITHOUT 
+	WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. ! See the 
+	License for the specific language governing permissions and ! limitations 
+	under the License. ! -->
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<artifactId>hivesterix-dist</artifactId>
 	<name>hivesterix-dist</name>
 
 	<parent>
-                <groupId>edu.uci.ics.hyracks</groupId>
-                <artifactId>hivesterix</artifactId>
-                <version>0.2.7-SNAPSHOT</version>
-        </parent>
+		<groupId>edu.uci.ics.hyracks</groupId>
+		<artifactId>hivesterix</artifactId>
+		<version>0.2.10-SNAPSHOT</version>
+	</parent>
 
 	<dependencies>
 		<dependency>
@@ -32,298 +27,37 @@
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
-			<groupId>junit</groupId>
-			<artifactId>junit</artifactId>
-			<version>4.8.1</version>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>args4j</groupId>
-			<artifactId>args4j</artifactId>
-			<version>2.0.12</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.json</groupId>
-			<artifactId>json</artifactId>
-			<version>20090211</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.eclipse.jetty</groupId>
-			<artifactId>jetty-server</artifactId>
-			<version>8.0.0.M1</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.eclipse.jetty</groupId>
-			<artifactId>jetty-servlet</artifactId>
-			<version>8.0.0.M1</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>jline</groupId>
-			<artifactId>jline</artifactId>
-			<version>0.9.94</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.datanucleus</groupId>
-			<artifactId>datanucleus-core</artifactId>
-			<version>2.0.3</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.datanucleus</groupId>
-			<artifactId>datanucleus-connectionpool</artifactId>
-			<version>2.0.3</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.datanucleus</groupId>
-			<artifactId>datanucleus-enhancer</artifactId>
-			<version>2.0.3</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.datanucleus</groupId>
-			<artifactId>datanucleus-rdbms</artifactId>
-			<version>2.0.3</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>commons-dbcp</groupId>
-			<artifactId>commons-dbcp</artifactId>
-			<version>1.4</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>commons-pool</groupId>
-			<artifactId>commons-pool</artifactId>
-			<version>1.5.4</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>commons-collections</groupId>
-			<artifactId>commons-collections</artifactId>
-			<version>3.2.1</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>commons-lang</groupId>
-			<artifactId>commons-lang</artifactId>
-			<version>2.4</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>javax</groupId>
-			<artifactId>jdo2-api</artifactId>
-			<version>2.3-ec</version>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>com.facebook</groupId>
-			<artifactId>libfb303</artifactId>
-			<version>0.5.0</version>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.thrift</groupId>
-			<artifactId>libthrift</artifactId>
-			<version>0.5.0</version>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.commons</groupId>
-			<artifactId>cli</artifactId>
-			<version>1.2</version>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.apache</groupId>
-			<artifactId>log4j</artifactId>
-			<version>1.2.15</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.antlr</groupId>
-			<artifactId>antlr-runtime</artifactId>
-			<version>3.0.1</version>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.hadoop.hive</groupId>
-			<artifactId>hive-cli</artifactId>
-			<version>0.7.0</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.hadoop.hive</groupId>
-			<artifactId>hive-common</artifactId>
-			<version>0.7.0</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.hadoop.hive</groupId>
-			<artifactId>hive-exec</artifactId>
-			<version>0.7.0</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.hadoop.hive</groupId>
-			<artifactId>hive-hwi</artifactId>
-			<version>0.7.0</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.hadoop.hive</groupId>
-			<artifactId>hive-jdbc</artifactId>
-			<version>0.7.0</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.hadoop.hive</groupId>
-			<artifactId>hive-metastore</artifactId>
-			<version>0.7.0</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.hadoop.hive</groupId>
-			<artifactId>hive-service</artifactId>
-			<version>0.7.0</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.hadoop.hive</groupId>
-			<artifactId>hive-shims</artifactId>
-			<version>0.7.0</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.hadoop.hive</groupId>
-			<artifactId>hive-serde</artifactId>
-			<version>0.7.0</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.slf4j</groupId>
-			<artifactId>slf4j-api</artifactId>
-			<version>1.6.1</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>commons-cli</groupId>
-			<artifactId>commons-cli</artifactId>
-			<version>1.2</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.slf4j</groupId>
-			<artifactId>slf4j-log4j12</artifactId>
-			<version>1.6.1</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>commons-logging</groupId>
-			<artifactId>commons-logging</artifactId>
-			<version>1.1.1</version>
-			<type>jar</type>
-			<classifier>api</classifier>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>com.google.guava</groupId>
-			<artifactId>guava</artifactId>
-			<version>r06</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.antlr</groupId>
-			<artifactId>stringtemplate</artifactId>
-			<version>3.2</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.derby</groupId>
-			<artifactId>derby</artifactId>
-			<version>10.8.1.2</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.hadoop</groupId>
-			<artifactId>hadoop-core</artifactId>
-			<version>0.20.2</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hivesterix-translator</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hivesterix-optimizer</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.hbase</groupId>
-			<artifactId>hbase</artifactId>
-			<version>0.90.3</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>algebricks-compiler</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-control-cc</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-control-nc</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
@@ -474,6 +208,23 @@
 				</executions>
 			</plugin>
 			<plugin>
+				<artifactId>maven-assembly-plugin</artifactId>
+				<version>2.2-beta-5</version>
+				<executions>
+					<execution>
+						<configuration>
+							<descriptors>
+								<descriptor>src/main/assembly/binary-assembly.xml</descriptor>
+							</descriptors>
+						</configuration>
+						<phase>package</phase>
+						<goals>
+							<goal>attached</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
+			<plugin>
 				<artifactId>maven-clean-plugin</artifactId>
 				<version>2.5</version>
 				<configuration>
diff --git a/hivesterix/hivesterix-dist/src/main/assembly/binary-assembly.xml b/hivesterix/hivesterix-dist/src/main/assembly/binary-assembly.xml
index aeb3fb4..e2da26a 100755
--- a/hivesterix/hivesterix-dist/src/main/assembly/binary-assembly.xml
+++ b/hivesterix/hivesterix-dist/src/main/assembly/binary-assembly.xml
@@ -1,17 +1,12 @@
-<!--
- ! Copyright 2009-2013 by The Regents of the University of California
- ! Licensed under the Apache License, Version 2.0 (the "License");
- ! you may not use this file except in compliance with the License.
- ! you may obtain a copy of the License from
- ! 
- !     http://www.apache.org/licenses/LICENSE-2.0
- ! 
- ! Unless required by applicable law or agreed to in writing, software
- ! distributed under the License is distributed on an "AS IS" BASIS,
- ! WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- ! See the License for the specific language governing permissions and
- ! limitations under the License.
- !-->
+<!-- ! Copyright 2009-2013 by The Regents of the University of California 
+	! Licensed under the Apache License, Version 2.0 (the "License"); ! you may 
+	not use this file except in compliance with the License. ! you may obtain 
+	a copy of the License from ! ! http://www.apache.org/licenses/LICENSE-2.0 
+	! ! Unless required by applicable law or agreed to in writing, software ! 
+	distributed under the License is distributed on an "AS IS" BASIS, ! WITHOUT 
+	WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. ! See the 
+	License for the specific language governing permissions and ! limitations 
+	under the License. ! -->
 <assembly>
 	<id>binary-assembly</id>
 	<formats>
@@ -21,20 +16,30 @@
 	<includeBaseDirectory>false</includeBaseDirectory>
 	<fileSets>
 		<fileSet>
-			<directory>target/appassembler/bin</directory>
+			<directory>src/main/resources/conf</directory>
+			<outputDirectory>conf</outputDirectory>
+			<fileMode>0755</fileMode>
+		</fileSet>
+		<fileSet>
+			<directory>src/main/resources/scripts</directory>
 			<outputDirectory>bin</outputDirectory>
 			<fileMode>0755</fileMode>
 		</fileSet>
 		<fileSet>
 			<directory>target/appassembler/lib</directory>
 			<outputDirectory>lib</outputDirectory>
+			<includes>
+				<include>*.jar</include>
+			</includes>
+			<fileMode>0755</fileMode>
 		</fileSet>
 		<fileSet>
 			<directory>target</directory>
 			<outputDirectory>lib</outputDirectory>
 			<includes>
-				<include>*.jar</include>
+				<include>a-hive-patch.jar</include>
 			</includes>
+			<fileMode>0755</fileMode>
 		</fileSet>
 	</fileSets>
-</assembly>
+</assembly>
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/main/java/edu/uci/ics/hivesterix/runtime/exec/HyracksExecutionEngine.java b/hivesterix/hivesterix-dist/src/main/java/edu/uci/ics/hivesterix/runtime/exec/HyracksExecutionEngine.java
index d3bcaca..7b88de4 100644
--- a/hivesterix/hivesterix-dist/src/main/java/edu/uci/ics/hivesterix/runtime/exec/HyracksExecutionEngine.java
+++ b/hivesterix/hivesterix-dist/src/main/java/edu/uci/ics/hivesterix/runtime/exec/HyracksExecutionEngine.java
@@ -36,16 +36,20 @@
 import org.apache.hadoop.hive.ql.exec.ConditionalTask;
 import org.apache.hadoop.hive.ql.exec.FileSinkOperator;
 import org.apache.hadoop.hive.ql.exec.MapRedTask;
+import org.apache.hadoop.hive.ql.exec.MoveTask;
 import org.apache.hadoop.hive.ql.exec.Operator;
 import org.apache.hadoop.hive.ql.exec.TableScanOperator;
 import org.apache.hadoop.hive.ql.exec.Task;
+import org.apache.hadoop.hive.ql.exec.Utilities;
 import org.apache.hadoop.hive.ql.plan.DynamicPartitionCtx;
 import org.apache.hadoop.hive.ql.plan.FetchWork;
 import org.apache.hadoop.hive.ql.plan.FileSinkDesc;
 import org.apache.hadoop.hive.ql.plan.MapredLocalWork;
 import org.apache.hadoop.hive.ql.plan.MapredWork;
+import org.apache.hadoop.hive.ql.plan.OperatorDesc;
 import org.apache.hadoop.hive.ql.plan.PartitionDesc;
 import org.apache.hadoop.hive.ql.plan.TableScanDesc;
+import org.apache.hadoop.mapred.Reporter;
 
 import edu.uci.ics.hivesterix.common.config.ConfUtil;
 import edu.uci.ics.hivesterix.logical.expression.HiveExpressionTypeComputer;
@@ -214,7 +218,6 @@
 
         // get all leave Ops
         getLeaves(rootOps, leaveOps);
-
         HiveAlgebricksTranslator translator = new HiveAlgebricksTranslator();
         try {
             translator.translate(rootOps, null, aliasToPath);
@@ -222,7 +225,7 @@
             ILogicalPlan plan = translator.genLogicalPlan();
 
             if (plan.getRoots() != null && plan.getRoots().size() > 0 && plan.getRoots().get(0).getValue() != null) {
-                translator.printOperators();
+                //translator.printOperators();
                 ILogicalPlanAndMetadata planAndMetadata = new HiveLogicalPlanAndMetaData(plan,
                         translator.getMetadataProvider());
 
@@ -238,7 +241,7 @@
                 StringBuilder buffer = new StringBuilder();
                 PlanPrettyPrinter.printPlan(plan, buffer, pvisitor, 0);
                 String planStr = buffer.toString();
-                System.out.println(planStr);
+                LOG.info(planStr);
 
                 if (planPrinter != null)
                     planPrinter.print(planStr);
@@ -377,6 +380,12 @@
                 // remove map-reduce branches in condition task
                 ConditionalTask condition = (ConditionalTask) task;
                 List<Task<? extends Serializable>> branches = condition.getListTasks();
+                for (Task branch : branches) {
+                    if (branch instanceof MoveTask) {
+                        //return articulateMapReduceOperators(branch, rootOps, aliasToPath, rootTasks);
+                        return null;
+                    }
+                }
                 for (int i = branches.size() - 1; i >= 0; i--) {
                     Task branch = branches.get(i);
                     if (branch instanceof MapRedTask) {
@@ -396,7 +405,7 @@
 
         MapRedTask mrtask = (MapRedTask) task;
         MapredWork work = (MapredWork) mrtask.getWork();
-        HashMap<String, Operator<? extends Serializable>> operators = work.getAliasToWork();
+        HashMap<String, Operator<? extends OperatorDesc>> operators = work.getAliasToWork();
 
         Set entries = operators.entrySet();
         Iterator<Entry<String, Operator>> iterator = entries.iterator();
@@ -414,7 +423,7 @@
         // get map local work
         MapredLocalWork localWork = work.getMapLocalWork();
         if (localWork != null) {
-            HashMap<String, Operator<? extends Serializable>> localOperators = localWork.getAliasToWork();
+            HashMap<String, Operator<? extends OperatorDesc>> localOperators = localWork.getAliasToWork();
 
             Set localEntries = localOperators.entrySet();
             Iterator<Entry<String, Operator>> localIterator = localEntries.iterator();
@@ -479,9 +488,9 @@
                 for (Operator childMap : childMapOps) {
                     if (childMap instanceof TableScanOperator) {
                         TableScanDesc topDesc = (TableScanDesc) childMap.getConf();
-                        if (topDesc == null)
+                        if (topDesc == null || topDesc.getAlias() == null) {
                             mapChildren.add(childMap);
-                        else {
+                        } else {
                             rootOps.add(childMap);
                         }
                     } else {
@@ -501,9 +510,14 @@
                 }
                 i = 0;
                 for (Operator child : mapChildren) {
-                    if (child.getParentOperators() == null || child.getParentOperators().size() == 0)
+                    if (child.getParentOperators() == null || child.getParentOperators().size() == 0) {
                         child.setParentOperators(new ArrayList<Operator>());
-                    child.getParentOperators().add(leafs.get(i));
+                    }
+                    if (i < leafs.size()) {
+                        if (child.getParentOperators().size()==0) {
+                            child.getParentOperators().add(leafs.get(i));
+                        }
+                    }
                     i++;
                 }
             }
@@ -603,10 +617,10 @@
             String specPath = desc.getDirName();
             DynamicPartitionCtx dpCtx = desc.getDynPartCtx();
             // for 0.7.0
-            fsOp.mvFileToFinalPath(specPath, conf, true, LOG, dpCtx);
+            //fsOp.mvFileToFinalPath(specPath, conf, true, LOG, dpCtx);
             // for 0.8.0
-            // Utilities.mvFileToFinalPath(specPath, conf, true, LOG, dpCtx,
-            // desc);
+            //Utilities.mvFileToFinalPath(specPath, conf, true, LOG, dpCtx, desc);
+            Utilities.mvFileToFinalPath(specPath, conf, true, LOG, dpCtx, desc, Reporter.NULL);
         }
     }
 }
diff --git a/hivesterix/hivesterix-dist/src/main/java/org/apache/hadoop/hive/ql/Driver.java b/hivesterix/hivesterix-dist/src/main/java/org/apache/hadoop/hive/ql/Driver.java
index 4ef74e9..64a3f12 100644
--- a/hivesterix/hivesterix-dist/src/main/java/org/apache/hadoop/hive/ql/Driver.java
+++ b/hivesterix/hivesterix-dist/src/main/java/org/apache/hadoop/hive/ql/Driver.java
@@ -1,17 +1,3 @@
-/*
- * Copyright 2009-2013 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
 /**
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
@@ -42,11 +28,13 @@
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
+import java.util.LinkedHashMap;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Queue;
 import java.util.Set;
+import java.util.concurrent.ConcurrentLinkedQueue;
 
 import org.apache.commons.lang.StringUtils;
 import org.apache.commons.logging.Log;
@@ -62,6 +50,7 @@
 import org.apache.hadoop.hive.ql.exec.ExecDriver;
 import org.apache.hadoop.hive.ql.exec.FetchTask;
 import org.apache.hadoop.hive.ql.exec.MapRedTask;
+import org.apache.hadoop.hive.ql.exec.MoveTask;
 import org.apache.hadoop.hive.ql.exec.Operator;
 import org.apache.hadoop.hive.ql.exec.StatsTask;
 import org.apache.hadoop.hive.ql.exec.TableScanOperator;
@@ -86,23 +75,22 @@
 import org.apache.hadoop.hive.ql.lockmgr.HiveLockObject;
 import org.apache.hadoop.hive.ql.lockmgr.HiveLockObject.HiveLockObjectData;
 import org.apache.hadoop.hive.ql.lockmgr.LockException;
+import org.apache.hadoop.hive.ql.log.PerfLogger;
 import org.apache.hadoop.hive.ql.metadata.AuthorizationException;
 import org.apache.hadoop.hive.ql.metadata.DummyPartition;
 import org.apache.hadoop.hive.ql.metadata.Hive;
 import org.apache.hadoop.hive.ql.metadata.HiveException;
-import org.apache.hadoop.hive.ql.metadata.HiveUtils;
 import org.apache.hadoop.hive.ql.metadata.Partition;
 import org.apache.hadoop.hive.ql.metadata.Table;
 import org.apache.hadoop.hive.ql.optimizer.ppr.PartitionPruner;
 import org.apache.hadoop.hive.ql.parse.ASTNode;
 import org.apache.hadoop.hive.ql.parse.AbstractSemanticAnalyzerHook;
 import org.apache.hadoop.hive.ql.parse.BaseSemanticAnalyzer;
-import org.apache.hadoop.hive.ql.parse.ErrorMsg;
 import org.apache.hadoop.hive.ql.parse.HiveSemanticAnalyzerHookContext;
 import org.apache.hadoop.hive.ql.parse.HiveSemanticAnalyzerHookContextImpl;
+import org.apache.hadoop.hive.ql.parse.ImportSemanticAnalyzer;
 import org.apache.hadoop.hive.ql.parse.ParseContext;
 import org.apache.hadoop.hive.ql.parse.ParseDriver;
-import org.apache.hadoop.hive.ql.parse.ParseException;
 import org.apache.hadoop.hive.ql.parse.ParseUtils;
 import org.apache.hadoop.hive.ql.parse.PrunedPartitionList;
 import org.apache.hadoop.hive.ql.parse.SemanticAnalyzer;
@@ -112,6 +100,7 @@
 import org.apache.hadoop.hive.ql.plan.ConditionalResolver;
 import org.apache.hadoop.hive.ql.plan.ConditionalResolverMergeFiles;
 import org.apache.hadoop.hive.ql.plan.HiveOperation;
+import org.apache.hadoop.hive.ql.plan.OperatorDesc;
 import org.apache.hadoop.hive.ql.plan.TableDesc;
 import org.apache.hadoop.hive.ql.processors.CommandProcessor;
 import org.apache.hadoop.hive.ql.processors.CommandProcessorResponse;
@@ -127,15 +116,18 @@
 import edu.uci.ics.hivesterix.runtime.exec.HyracksExecutionEngine;
 import edu.uci.ics.hivesterix.runtime.exec.IExecutionEngine;
 
-@SuppressWarnings({ "deprecation", "unused" })
+@SuppressWarnings({ "deprecation", "unchecked", "rawtypes" })
 public class Driver implements CommandProcessor {
 
+    // hivesterix
+    private IExecutionEngine engine;
+    private boolean hivesterix = false;
+    private Set<Task> executedConditionalTsks = new HashSet<Task>();
+
     static final private Log LOG = LogFactory.getLog(Driver.class.getName());
     static final private LogHelper console = new LogHelper(LOG);
 
-    // hive-sterix
-    private IExecutionEngine engine;
-    private boolean hivesterix = false;
+    private static final Object compileMonitor = new Object();
 
     private int maxRows = 100;
     ByteStream.Output bos = new ByteStream.Output();
@@ -152,23 +144,57 @@
 
     // A limit on the number of threads that can be launched
     private int maxthreads;
-    private final int sleeptime = 2000;
-
+    private static final int SLEEP_TIME = 2000;
     protected int tryCount = Integer.MAX_VALUE;
 
-    private int checkLockManager() {
+    /**
+     * for backwards compatibility with current tests
+     */
+    public Driver(HiveConf conf) {
+        this.conf = conf;
+
+    }
+
+    public Driver() {
+        if (SessionState.get() != null) {
+            conf = SessionState.get().getConf();
+        }
+
+        // hivesterix
+        engine = new HyracksExecutionEngine(conf);
+    }
+
+    // hivesterix: plan printer
+    public Driver(HiveConf conf, PrintWriter planPrinter) {
+        this.conf = conf;
+        engine = new HyracksExecutionEngine(conf, planPrinter);
+    }
+
+    public void clear() {
+        this.hivesterix = false;
+        this.executedConditionalTsks.clear();
+    }
+
+    private boolean checkLockManager() {
         boolean supportConcurrency = conf.getBoolVar(HiveConf.ConfVars.HIVE_SUPPORT_CONCURRENCY);
-        if (supportConcurrency && (hiveLockMgr == null)) {
+        if (!supportConcurrency) {
+            return false;
+        }
+        if ((hiveLockMgr == null)) {
             try {
                 setLockManager();
             } catch (SemanticException e) {
                 errorMessage = "FAILED: Error in semantic analysis: " + e.getMessage();
                 SQLState = ErrorMsg.findSQLState(e.getMessage());
                 console.printError(errorMessage, "\n" + org.apache.hadoop.util.StringUtils.stringifyException(e));
-                return (12);
+                return false;
             }
         }
-        return (0);
+        // the reason that we set the lock manager for the cxt here is because each
+        // query has its own ctx object. The hiveLockMgr is shared accross the
+        // same instance of Driver, which can run multiple queries.
+        ctx.setHiveLockMgr(hiveLockMgr);
+        return hiveLockMgr != null;
     }
 
     private void setLockManager() throws SemanticException {
@@ -183,6 +209,16 @@
                 hiveLockMgr = (HiveLockManager) ReflectionUtils.newInstance(conf.getClassByName(lockMgr), conf);
                 hiveLockMgr.setContext(new HiveLockManagerCtx(conf));
             } catch (Exception e) {
+                // set hiveLockMgr to null just in case this invalid manager got set to
+                // next query's ctx.
+                if (hiveLockMgr != null) {
+                    try {
+                        hiveLockMgr.close();
+                    } catch (LockException e1) {
+                        //nothing can do here
+                    }
+                    hiveLockMgr = null;
+                }
                 throw new SemanticException(ErrorMsg.LOCKMGR_NOT_INITIALIZED.getMsg() + e.getMessage());
             }
         }
@@ -230,10 +266,8 @@
         } else if (sem.getFetchTask() != null) {
             FetchTask ft = sem.getFetchTask();
             TableDesc td = ft.getTblDesc();
-            // partitioned tables don't have tableDesc set on the FetchTask.
-            // Instead
-            // they have a list of PartitionDesc objects, each with a table
-            // desc.
+            // partitioned tables don't have tableDesc set on the FetchTask. Instead
+            // they have a list of PartitionDesc objects, each with a table desc.
             // Let's
             // try to fetch the desc for the first partition and use it's
             // deserializer.
@@ -320,59 +354,102 @@
     }
 
     /**
-     * for backwards compatibility with current tests
-     */
-    public Driver(HiveConf conf) {
-        this.conf = conf;
-
-        // hivesterix
-        engine = new HyracksExecutionEngine(conf);
-    }
-
-    public Driver() {
-        if (SessionState.get() != null) {
-            conf = SessionState.get().getConf();
-        }
-
-        // hivesterix
-        engine = new HyracksExecutionEngine(conf);
-    }
-
-    // hivesterix: plan printer
-    public Driver(HiveConf conf, PrintWriter planPrinter) {
-        this.conf = conf;
-        engine = new HyracksExecutionEngine(conf, planPrinter);
-    }
-
-    public void clear() {
-        this.hivesterix = false;
-    }
-
-    /**
-     * Compile a new query. Any currently-planned query associated with this
-     * Driver is discarded.
+     * Compile a new query. Any currently-planned query associated with this Driver is discarded.
      * 
      * @param command
      *            The SQL query to compile.
      */
     public int compile(String command) {
+        return compile(command, true);
+    }
+
+    /**
+     * Hold state variables specific to each query being executed, that may not
+     * be consistent in the overall SessionState
+     */
+    private static class QueryState {
+        private HiveOperation op;
+        private String cmd;
+        private boolean init = false;
+
+        /**
+         * Initialize the queryState with the query state variables
+         */
+        public void init(HiveOperation op, String cmd) {
+            this.op = op;
+            this.cmd = cmd;
+            this.init = true;
+        }
+
+        public boolean isInitialized() {
+            return this.init;
+        }
+
+        public HiveOperation getOp() {
+            return this.op;
+        }
+
+        public String getCmd() {
+            return this.cmd;
+        }
+    }
+
+    public void saveSession(QueryState qs) {
+        SessionState oldss = SessionState.get();
+        if (oldss != null && oldss.getHiveOperation() != null) {
+            qs.init(oldss.getHiveOperation(), oldss.getCmd());
+        }
+    }
+
+    public void restoreSession(QueryState qs) {
+        SessionState ss = SessionState.get();
+        if (ss != null && qs != null && qs.isInitialized()) {
+            ss.setCmd(qs.getCmd());
+            ss.setCommandType(qs.getOp());
+        }
+    }
+
+    /**
+     * Compile a new query, but potentially reset taskID counter. Not resetting task counter
+     * is useful for generating re-entrant QL queries.
+     * 
+     * @param command
+     *            The HiveQL query to compile
+     * @param resetTaskIds
+     *            Resets taskID counter if true.
+     * @return 0 for ok
+     */
+    public int compile(String command, boolean resetTaskIds) {
+        PerfLogger perfLogger = PerfLogger.getPerfLogger();
+        perfLogger.PerfLogBegin(LOG, PerfLogger.COMPILE);
+
+        //holder for parent command type/string when executing reentrant queries
+        QueryState queryState = new QueryState();
+
         if (plan != null) {
             close();
             plan = null;
         }
 
-        TaskFactory.resetId();
+        if (resetTaskIds) {
+            TaskFactory.resetId();
+        }
+        saveSession(queryState);
 
         try {
             command = new VariableSubstitution().substitute(conf, command);
             ctx = new Context(conf);
+            ctx.setTryCount(getTryCount());
+            ctx.setCmd(command);
+            ctx.setHDFSCleanup(true);
 
             ParseDriver pd = new ParseDriver();
             ASTNode tree = pd.parse(command, ctx);
             tree = ParseUtils.findRootNonNullToken(tree);
 
             BaseSemanticAnalyzer sem = SemanticAnalyzerFactory.get(conf, tree);
-            List<AbstractSemanticAnalyzerHook> saHooks = getSemanticAnalyzerHooks();
+            List<AbstractSemanticAnalyzerHook> saHooks = getHooks(HiveConf.ConfVars.SEMANTIC_ANALYZER_HOOK,
+                    AbstractSemanticAnalyzerHook.class);
 
             // Do semantic analysis and plan generation
             if (saHooks != null) {
@@ -382,6 +459,7 @@
                     tree = hook.preAnalyze(hookCtx, tree);
                 }
                 sem.analyze(tree, ctx);
+                hookCtx.update(sem);
                 for (AbstractSemanticAnalyzerHook hook : saHooks) {
                     hook.postAnalyze(hookCtx, sem.getRootTasks());
                 }
@@ -394,19 +472,10 @@
             // validate the plan
             sem.validate();
 
-            plan = new QueryPlan(command, sem);
-            // initialize FetchTask right here
-            if (plan.getFetchTask() != null) {
-                plan.getFetchTask().initialize(conf, plan, null);
-            }
-
-            // get the output schema
-            schema = getSchema(sem, conf);
+            plan = new QueryPlan(command, sem, perfLogger.getStartTime(PerfLogger.DRIVER_RUN));
 
             // test Only - serialize the query plan and deserialize it
-            if (sem instanceof SemanticAnalyzer && command.toLowerCase().indexOf("create") < 0) {
-
-                Thread.currentThread().setContextClassLoader(this.getClass().getClassLoader());
+            if ("true".equalsIgnoreCase(System.getProperty("test.serialize.qplan"))) {
 
                 String queryPlanFileName = ctx.getLocalScratchDir(true) + Path.SEPARATOR_CHAR + "queryplan.xml";
                 LOG.info("query plan = " + queryPlanFileName);
@@ -431,17 +500,24 @@
                 plan.getFetchTask().initialize(conf, plan, null);
             }
 
-            // do the authorization check
+            // get the output schema
+            schema = getSchema(sem, conf);
+
+            //do the authorization check
             if (HiveConf.getBoolVar(conf, HiveConf.ConfVars.HIVE_AUTHORIZATION_ENABLED)) {
                 try {
-                    // doAuthorization(sem);
+                    perfLogger.PerfLogBegin(LOG, PerfLogger.DO_AUTHORIZATION);
+                    doAuthorization(sem);
                 } catch (AuthorizationException authExp) {
                     console.printError("Authorization failed:" + authExp.getMessage()
                             + ". Use show grant to get more details.");
                     return 403;
+                } finally {
+                    perfLogger.PerfLogEnd(LOG, PerfLogger.DO_AUTHORIZATION);
                 }
             }
 
+            //restore state after we're done executing a specific query
             // hyracks run
             if (sem instanceof SemanticAnalyzer && command.toLowerCase().indexOf("create") < 0) {
                 int engineRet = engine.compileJob(sem.getRootTasks());
@@ -450,21 +526,19 @@
                 }
             }
             return 0;
-        } catch (SemanticException e) {
-            errorMessage = "FAILED: Error in semantic analysis: " + e.getMessage();
-            SQLState = ErrorMsg.findSQLState(e.getMessage());
-            console.printError(errorMessage, "\n" + org.apache.hadoop.util.StringUtils.stringifyException(e));
-            return (10);
-        } catch (ParseException e) {
-            errorMessage = "FAILED: Parse Error: " + e.getMessage();
-            SQLState = ErrorMsg.findSQLState(e.getMessage());
-            console.printError(errorMessage, "\n" + org.apache.hadoop.util.StringUtils.stringifyException(e));
-            return (11);
         } catch (Exception e) {
-            errorMessage = "FAILED: Hive Internal Error: " + Utilities.getNameMessage(e);
-            SQLState = ErrorMsg.findSQLState(e.getMessage());
-            console.printError(errorMessage + "\n" + org.apache.hadoop.util.StringUtils.stringifyException(e));
-            return (12);
+            ErrorMsg error = ErrorMsg.getErrorMsg(e.getMessage());
+            errorMessage = "FAILED: " + e.getClass().getSimpleName();
+            if (error != ErrorMsg.GENERIC_ERROR) {
+                errorMessage += " [Error " + error.getErrorCode() + "]:";
+            }
+            errorMessage += " " + e.getMessage();
+            SQLState = error.getSQLState();
+            console.printError(errorMessage, "\n" + org.apache.hadoop.util.StringUtils.stringifyException(e));
+            return error.getErrorCode();
+        } finally {
+            perfLogger.PerfLogEnd(LOG, PerfLogger.COMPILE);
+            restoreSession(queryState);
         }
     }
 
@@ -479,13 +553,13 @@
                 ss.getAuthorizer().authorize(db.getDatabase(db.getCurrentDatabase()), null,
                         HiveOperation.CREATETABLE_AS_SELECT.getOutputRequiredPrivileges());
             } else {
-                // if (op.equals(HiveOperation.IMPORT)) {
-                // ImportSemanticAnalyzer isa = (ImportSemanticAnalyzer) sem;
-                // if (!isa.existsTable()) {
-                ss.getAuthorizer().authorize(db.getDatabase(db.getCurrentDatabase()), null,
-                        HiveOperation.CREATETABLE_AS_SELECT.getOutputRequiredPrivileges());
-                // }
-                // }
+                if (op.equals(HiveOperation.IMPORT)) {
+                    ImportSemanticAnalyzer isa = (ImportSemanticAnalyzer) sem;
+                    if (!isa.existsTable()) {
+                        ss.getAuthorizer().authorize(db.getDatabase(db.getCurrentDatabase()), null,
+                                HiveOperation.CREATETABLE_AS_SELECT.getOutputRequiredPrivileges());
+                    }
+                }
             }
             if (outputs != null && outputs.size() > 0) {
                 for (WriteEntity write : outputs) {
@@ -513,8 +587,8 @@
 
             Map<String, Boolean> tableUsePartLevelAuth = new HashMap<String, Boolean>();
             for (ReadEntity read : inputs) {
-                if (read.getPartition() != null) {
-                    Table tbl = read.getTable();
+                Table tbl = read.getTable();
+                if ((read.getPartition() != null) || (tbl.isPartitioned())) {
                     String tblName = tbl.getTableName();
                     if (tableUsePartLevelAuth.get(tblName) == null) {
                         boolean usePartLevelPriv = (tbl.getParameters().get("PARTITION_LEVEL_PRIVILEGE") != null && ("TRUE"
@@ -533,9 +607,9 @@
                 ParseContext parseCtx = querySem.getParseContext();
                 Map<TableScanOperator, Table> tsoTopMap = parseCtx.getTopToTable();
 
-                for (Map.Entry<String, Operator<? extends Serializable>> topOpMap : querySem.getParseContext()
+                for (Map.Entry<String, Operator<? extends OperatorDesc>> topOpMap : querySem.getParseContext()
                         .getTopOps().entrySet()) {
-                    Operator<? extends Serializable> topOp = topOpMap.getValue();
+                    Operator<? extends OperatorDesc> topOp = topOpMap.getValue();
                     if (topOp instanceof TableScanOperator && tsoTopMap.containsKey(topOp)) {
                         TableScanOperator tableScanOp = (TableScanOperator) topOp;
                         Table tbl = tsoTopMap.get(tableScanOp);
@@ -551,7 +625,10 @@
                                 cols.add(columns.get(i).getName());
                             }
                         }
-                        if (tbl.isPartitioned() && tableUsePartLevelAuth.get(tbl.getTableName())) {
+                        //map may not contain all sources, since input list may have been optimized out
+                        //or non-existent tho such sources may still be referenced by the TableScanOperator
+                        //if it's null then the partition probably doesn't exist so let's use table permission
+                        if (tbl.isPartitioned() && tableUsePartLevelAuth.get(tbl.getTableName()) == Boolean.TRUE) {
                             String alias_id = topOpMap.getKey();
                             PrunedPartitionList partsList = PartitionPruner.prune(parseCtx.getTopToTable().get(topOp),
                                     parseCtx.getOpToPartPruner().get(topOp), parseCtx.getConf(), alias_id,
@@ -582,30 +659,28 @@
             // cache the results for table authorization
             Set<String> tableAuthChecked = new HashSet<String>();
             for (ReadEntity read : inputs) {
-                Table tbl = null;
+                Table tbl = read.getTable();
                 if (read.getPartition() != null) {
-                    tbl = read.getPartition().getTable();
+                    Partition partition = read.getPartition();
+                    tbl = partition.getTable();
                     // use partition level authorization
-                    if (tableUsePartLevelAuth.get(tbl.getTableName())) {
-                        List<String> cols = part2Cols.get(read.getPartition());
+                    if (tableUsePartLevelAuth.get(tbl.getTableName()) == Boolean.TRUE) {
+                        List<String> cols = part2Cols.get(partition);
                         if (cols != null && cols.size() > 0) {
-                            ss.getAuthorizer().authorize(read.getPartition().getTable(), read.getPartition(), cols,
+                            ss.getAuthorizer().authorize(partition.getTable(), partition, cols,
                                     op.getInputRequiredPrivileges(), null);
                         } else {
-                            ss.getAuthorizer().authorize(read.getPartition(), op.getInputRequiredPrivileges(), null);
+                            ss.getAuthorizer().authorize(partition, op.getInputRequiredPrivileges(), null);
                         }
                         continue;
                     }
-                } else if (read.getTable() != null) {
-                    tbl = read.getTable();
                 }
 
-                // if we reach here, it means it needs to do a table
-                // authorization
-                // check, and the table authorization may already happened
-                // because of other
+                // if we reach here, it means it needs to do a table authorization
+                // check, and the table authorization may already happened because of other
                 // partitions
-                if (tbl != null && !tableAuthChecked.contains(tbl.getTableName())) {
+                if (tbl != null && !tableAuthChecked.contains(tbl.getTableName())
+                        && !(tableUsePartLevelAuth.get(tbl.getTableName()) == Boolean.TRUE)) {
                     List<String> cols = tab2Cols.get(tbl);
                     if (cols != null && cols.size() > 0) {
                         ss.getAuthorizer().authorize(tbl, null, cols, op.getInputRequiredPrivileges(), null);
@@ -632,16 +707,15 @@
      * @param p
      *            The partition to be locked
      * @param mode
-     *            The mode of the lock (SHARED/EXCLUSIVE) Get the list of
-     *            objects to be locked. If a partition needs to be locked (in
-     *            any mode), all its parents should also be locked in SHARED
-     *            mode.
+     *            The mode of the lock (SHARED/EXCLUSIVE) Get the list of objects to be locked. If a
+     *            partition needs to be locked (in any mode), all its parents should also be locked in
+     *            SHARED mode.
      **/
     private List<HiveLockObj> getLockObjects(Table t, Partition p, HiveLockMode mode) throws SemanticException {
         List<HiveLockObj> locks = new LinkedList<HiveLockObj>();
 
         HiveLockObjectData lockData = new HiveLockObjectData(plan.getQueryId(), String.valueOf(System
-                .currentTimeMillis()), "IMPLICIT");
+                .currentTimeMillis()), "IMPLICIT", plan.getQueryStr());
 
         if (t != null) {
             locks.add(new HiveLockObj(new HiveLockObject(t, lockData), mode));
@@ -665,16 +739,20 @@
                 name = p.getName().split("@")[2];
             }
 
-            String partName = name;
             String partialName = "";
             String[] partns = name.split("/");
             int len = p instanceof DummyPartition ? partns.length : partns.length - 1;
+            Map<String, String> partialSpec = new LinkedHashMap<String, String>();
             for (int idx = 0; idx < len; idx++) {
                 String partn = partns[idx];
                 partialName += partn;
+                String[] nameValue = partn.split("=");
+                assert (nameValue.length == 2);
+                partialSpec.put(nameValue[0], nameValue[1]);
                 try {
                     locks.add(new HiveLockObj(new HiveLockObject(new DummyPartition(p.getTable(), p.getTable()
-                            .getDbName() + "/" + p.getTable().getTableName() + "/" + partialName), lockData), mode));
+                            .getDbName() + "/" + p.getTable().getTableName() + "/" + partialName, partialSpec),
+                            lockData), mode));
                     partialName += "/";
                 } catch (HiveException e) {
                     throw new SemanticException(e.getMessage());
@@ -688,17 +766,16 @@
     }
 
     /**
-     * Acquire read and write locks needed by the statement. The list of objects
-     * to be locked are obtained from he inputs and outputs populated by the
-     * compiler. The lock acuisition scheme is pretty simple. If all the locks
-     * cannot be obtained, error out. Deadlock is avoided by making sure that
-     * the locks are lexicographically sorted.
+     * Acquire read and write locks needed by the statement. The list of objects to be locked are
+     * obtained from he inputs and outputs populated by the compiler. The lock acuisition scheme is
+     * pretty simple. If all the locks cannot be obtained, error out. Deadlock is avoided by making
+     * sure that the locks are lexicographically sorted.
      **/
     public int acquireReadWriteLocks() {
-        try {
-            int sleepTime = conf.getIntVar(HiveConf.ConfVars.HIVE_LOCK_SLEEP_BETWEEN_RETRIES) * 1000;
-            int numRetries = conf.getIntVar(HiveConf.ConfVars.HIVE_LOCK_NUMRETRIES);
+        PerfLogger perfLogger = PerfLogger.getPerfLogger();
+        perfLogger.PerfLogBegin(LOG, PerfLogger.ACQUIRE_READ_WRITE_LOCKS);
 
+        try {
             boolean supportConcurrency = conf.getBoolVar(HiveConf.ConfVars.HIVE_SUPPORT_CONCURRENCY);
             if (!supportConcurrency) {
                 return 0;
@@ -707,8 +784,7 @@
             List<HiveLockObj> lockObjects = new ArrayList<HiveLockObj>();
 
             // Sort all the inputs, outputs.
-            // If a lock needs to be acquired on any partition, a read lock
-            // needs to be acquired on all
+            // If a lock needs to be acquired on any partition, a read lock needs to be acquired on all
             // its parents also
             for (ReadEntity input : plan.getInputs()) {
                 if (input.getType() == ReadEntity.Type.TABLE) {
@@ -719,16 +795,21 @@
             }
 
             for (WriteEntity output : plan.getOutputs()) {
+                List<HiveLockObj> lockObj = null;
                 if (output.getTyp() == WriteEntity.Type.TABLE) {
-                    lockObjects.addAll(getLockObjects(output.getTable(), null,
-                            output.isComplete() ? HiveLockMode.EXCLUSIVE : HiveLockMode.SHARED));
+                    lockObj = getLockObjects(output.getTable(), null, output.isComplete() ? HiveLockMode.EXCLUSIVE
+                            : HiveLockMode.SHARED);
                 } else if (output.getTyp() == WriteEntity.Type.PARTITION) {
-                    lockObjects.addAll(getLockObjects(null, output.getPartition(), HiveLockMode.EXCLUSIVE));
+                    lockObj = getLockObjects(null, output.getPartition(), HiveLockMode.EXCLUSIVE);
                 }
-                // In case of dynamic queries, it is possible to have incomplete
-                // dummy partitions
+                // In case of dynamic queries, it is possible to have incomplete dummy partitions
                 else if (output.getTyp() == WriteEntity.Type.DUMMYPARTITION) {
-                    lockObjects.addAll(getLockObjects(null, output.getPartition(), HiveLockMode.SHARED));
+                    lockObj = getLockObjects(null, output.getPartition(), HiveLockMode.SHARED);
+                }
+
+                if (lockObj != null) {
+                    lockObjects.addAll(lockObj);
+                    ctx.getOutputLockObjects().put(output, lockObj);
                 }
             }
 
@@ -736,13 +817,8 @@
                 return 0;
             }
 
-            int ret = checkLockManager();
-            if (ret != 0) {
-                return ret;
-            }
-
             HiveLockObjectData lockData = new HiveLockObjectData(plan.getQueryId(), String.valueOf(System
-                    .currentTimeMillis()), "IMPLICIT");
+                    .currentTimeMillis()), "IMPLICIT", plan.getQueryStr());
 
             // Lock the database also
             try {
@@ -753,25 +829,7 @@
                 throw new SemanticException(e.getMessage());
             }
 
-            ctx.setHiveLockMgr(hiveLockMgr);
-            List<HiveLock> hiveLocks = null;
-
-            int tryNum = 1;
-            do {
-
-                // ctx.getHiveLockMgr();
-                // hiveLocks = ctx.getHiveLockMgr().lock(lockObjects, false);
-
-                if (hiveLocks != null) {
-                    break;
-                }
-
-                tryNum++;
-                try {
-                    Thread.sleep(sleepTime);
-                } catch (InterruptedException e) {
-                }
-            } while (tryNum < numRetries);
+            List<HiveLock> hiveLocks = ctx.getHiveLockMgr().lock(lockObjects, false);
 
             if (hiveLocks == null) {
                 throw new SemanticException(ErrorMsg.LOCK_CANNOT_BE_ACQUIRED.getMsg());
@@ -785,138 +843,207 @@
             SQLState = ErrorMsg.findSQLState(e.getMessage());
             console.printError(errorMessage, "\n" + org.apache.hadoop.util.StringUtils.stringifyException(e));
             return (10);
-        } catch (Exception e) {
+        } catch (LockException e) {
             errorMessage = "FAILED: Error in acquiring locks: " + e.getMessage();
             SQLState = ErrorMsg.findSQLState(e.getMessage());
             console.printError(errorMessage, "\n" + org.apache.hadoop.util.StringUtils.stringifyException(e));
             return (10);
-        }
-    }
-
-    /**
-     * Release all the locks acquired implicitly by the statement. Note that the
-     * locks acquired with 'keepAlive' set to True are not released.
-     **/
-    private void releaseLocks() {
-        if (ctx != null && ctx.getHiveLockMgr() != null) {
-            try {
-                ctx.getHiveLockMgr().close();
-                ctx.setHiveLocks(null);
-            } catch (LockException e) {
-            }
+        } finally {
+            perfLogger.PerfLogEnd(LOG, PerfLogger.ACQUIRE_READ_WRITE_LOCKS);
         }
     }
 
     /**
      * @param hiveLocks
-     *            list of hive locks to be released Release all the locks
-     *            specified. If some of the locks have already been released,
-     *            ignore them
+     *            list of hive locks to be released Release all the locks specified. If some of the
+     *            locks have already been released, ignore them
      **/
     private void releaseLocks(List<HiveLock> hiveLocks) {
+        PerfLogger perfLogger = PerfLogger.getPerfLogger();
+        perfLogger.PerfLogBegin(LOG, PerfLogger.RELEASE_LOCKS);
+
         if (hiveLocks != null) {
             ctx.getHiveLockMgr().releaseLocks(hiveLocks);
         }
         ctx.setHiveLocks(null);
+
+        perfLogger.PerfLogEnd(LOG, PerfLogger.RELEASE_LOCKS);
     }
 
-    public CommandProcessorResponse run(String command) {
+    public CommandProcessorResponse run(String command) throws CommandNeedRetryException {
         errorMessage = null;
         SQLState = null;
 
-        int ret = compile(command);
+        if (!validateConfVariables()) {
+            return new CommandProcessorResponse(12, errorMessage, SQLState);
+        }
+
+        HiveDriverRunHookContext hookContext = new HiveDriverRunHookContextImpl(conf, command);
+        // Get all the driver run hooks and pre-execute them.
+        List<HiveDriverRunHook> driverRunHooks;
+        try {
+            driverRunHooks = getHooks(HiveConf.ConfVars.HIVE_DRIVER_RUN_HOOKS, HiveDriverRunHook.class);
+            for (HiveDriverRunHook driverRunHook : driverRunHooks) {
+                driverRunHook.preDriverRun(hookContext);
+            }
+        } catch (Exception e) {
+            errorMessage = "FAILED: Hive Internal Error: " + Utilities.getNameMessage(e);
+            SQLState = ErrorMsg.findSQLState(e.getMessage());
+            console.printError(errorMessage + "\n" + org.apache.hadoop.util.StringUtils.stringifyException(e));
+            return new CommandProcessorResponse(12, errorMessage, SQLState);
+        }
+
+        // Reset the perf logger
+        PerfLogger perfLogger = PerfLogger.getPerfLogger(true);
+        perfLogger.PerfLogBegin(LOG, PerfLogger.DRIVER_RUN);
+        perfLogger.PerfLogBegin(LOG, PerfLogger.TIME_TO_SUBMIT);
+
+        int ret;
+        synchronized (compileMonitor) {
+            ret = compile(command);
+        }
         if (ret != 0) {
-            // releaseLocks(ctx.getHiveLocks());
+            releaseLocks(ctx.getHiveLocks());
             return new CommandProcessorResponse(ret, errorMessage, SQLState);
         }
 
-        // ret = acquireReadWriteLocks();
-        if (ret != 0) {
-            // releaseLocks(ctx.getHiveLocks());
-            return new CommandProcessorResponse(ret, errorMessage, SQLState);
+        boolean requireLock = false;
+        boolean ckLock = checkLockManager();
+
+        if (ckLock) {
+            boolean lockOnlyMapred = HiveConf.getBoolVar(conf, HiveConf.ConfVars.HIVE_LOCK_MAPRED_ONLY);
+            if (lockOnlyMapred) {
+                Queue<Task<? extends Serializable>> taskQueue = new LinkedList<Task<? extends Serializable>>();
+                taskQueue.addAll(plan.getRootTasks());
+                while (taskQueue.peek() != null) {
+                    Task<? extends Serializable> tsk = taskQueue.remove();
+                    requireLock = requireLock || tsk.requireLock();
+                    if (requireLock) {
+                        break;
+                    }
+                    if (tsk instanceof ConditionalTask) {
+                        taskQueue.addAll(((ConditionalTask) tsk).getListTasks());
+                    }
+                    if (tsk.getChildTasks() != null) {
+                        taskQueue.addAll(tsk.getChildTasks());
+                    }
+                    // does not add back up task here, because back up task should be the same
+                    // type of the original task.
+                }
+            } else {
+                requireLock = true;
+            }
+        }
+
+        if (requireLock) {
+            ret = acquireReadWriteLocks();
+            if (ret != 0) {
+                releaseLocks(ctx.getHiveLocks());
+                return new CommandProcessorResponse(ret, errorMessage, SQLState);
+            }
         }
 
         ret = execute();
         if (ret != 0) {
-            // releaseLocks(ctx.getHiveLocks());
+            //if needRequireLock is false, the release here will do nothing because there is no lock
+            releaseLocks(ctx.getHiveLocks());
             return new CommandProcessorResponse(ret, errorMessage, SQLState);
         }
 
-        // releaseLocks(ctx.getHiveLocks());
+        //if needRequireLock is false, the release here will do nothing because there is no lock
+        releaseLocks(ctx.getHiveLocks());
+
+        perfLogger.PerfLogEnd(LOG, PerfLogger.DRIVER_RUN);
+        perfLogger.close(LOG, plan);
+
+        // Take all the driver run hooks and post-execute them.
+        try {
+            for (HiveDriverRunHook driverRunHook : driverRunHooks) {
+                driverRunHook.postDriverRun(hookContext);
+            }
+        } catch (Exception e) {
+            errorMessage = "FAILED: Hive Internal Error: " + Utilities.getNameMessage(e);
+            SQLState = ErrorMsg.findSQLState(e.getMessage());
+            console.printError(errorMessage + "\n" + org.apache.hadoop.util.StringUtils.stringifyException(e));
+            return new CommandProcessorResponse(12, errorMessage, SQLState);
+        }
+
         return new CommandProcessorResponse(ret);
     }
 
-    private List<AbstractSemanticAnalyzerHook> getSemanticAnalyzerHooks() throws Exception {
-        ArrayList<AbstractSemanticAnalyzerHook> saHooks = new ArrayList<AbstractSemanticAnalyzerHook>();
-        String pestr = conf.getVar(HiveConf.ConfVars.SEMANTIC_ANALYZER_HOOK);
-        if (pestr == null) {
-            return saHooks;
+    /**
+     * Validate configuration variables.
+     * 
+     * @return
+     */
+    private boolean validateConfVariables() {
+        boolean valid = true;
+        if ((!conf.getBoolVar(HiveConf.ConfVars.HIVE_HADOOP_SUPPORTS_SUBDIRECTORIES))
+                && ((conf.getBoolVar(HiveConf.ConfVars.HADOOPMAPREDINPUTDIRRECURSIVE))
+                        || (conf.getBoolVar(HiveConf.ConfVars.HIVEOPTLISTBUCKETING)) || ((conf
+                            .getBoolVar(HiveConf.ConfVars.HIVE_OPTIMIZE_UNION_REMOVE))))) {
+            errorMessage = "FAILED: Hive Internal Error: " + ErrorMsg.SUPPORT_DIR_MUST_TRUE_FOR_LIST_BUCKETING.getMsg();
+            SQLState = ErrorMsg.findSQLState(errorMessage);
+            console.printError(errorMessage + "\n");
+            valid = false;
         }
-        pestr = pestr.trim();
-        if (pestr.equals("")) {
-            return saHooks;
-        }
-
-        String[] peClasses = pestr.split(",");
-
-        for (String peClass : peClasses) {
-            try {
-                AbstractSemanticAnalyzerHook hook = HiveUtils.getSemanticAnalyzerHook(conf, peClass);
-                saHooks.add(hook);
-            } catch (HiveException e) {
-                console.printError("Pre Exec Hook Class not found:" + e.getMessage());
-                throw e;
-            }
-        }
-
-        return saHooks;
+        return valid;
     }
 
-    private List<Hook> getPreExecHooks() throws Exception {
-        ArrayList<Hook> pehooks = new ArrayList<Hook>();
-        String pestr = conf.getVar(HiveConf.ConfVars.PREEXECHOOKS);
-        pestr = pestr.trim();
-        if (pestr.equals("")) {
-            return pehooks;
+    /**
+     * Returns a set of hooks specified in a configuration variable.
+     * See getHooks(HiveConf.ConfVars hookConfVar, Class<T> clazz)
+     * 
+     * @param hookConfVar
+     * @return
+     * @throws Exception
+     */
+    private List<Hook> getHooks(HiveConf.ConfVars hookConfVar) throws Exception {
+        return getHooks(hookConfVar, Hook.class);
+    }
+
+    /**
+     * Returns the hooks specified in a configuration variable. The hooks are returned in a list in
+     * the order they were specified in the configuration variable.
+     * 
+     * @param hookConfVar
+     *            The configuration variable specifying a comma separated list of the hook
+     *            class names.
+     * @param clazz
+     *            The super type of the hooks.
+     * @return A list of the hooks cast as the type specified in clazz, in the order
+     *         they are listed in the value of hookConfVar
+     * @throws Exception
+     */
+    private <T extends Hook> List<T> getHooks(HiveConf.ConfVars hookConfVar, Class<T> clazz) throws Exception {
+
+        List<T> hooks = new ArrayList<T>();
+        String csHooks = conf.getVar(hookConfVar);
+        if (csHooks == null) {
+            return hooks;
         }
 
-        String[] peClasses = pestr.split(",");
+        csHooks = csHooks.trim();
+        if (csHooks.equals("")) {
+            return hooks;
+        }
 
-        for (String peClass : peClasses) {
+        String[] hookClasses = csHooks.split(",");
+
+        for (String hookClass : hookClasses) {
             try {
-                pehooks.add((Hook) Class.forName(peClass.trim(), true, JavaUtils.getClassLoader()).newInstance());
+                T hook = (T) Class.forName(hookClass.trim(), true, JavaUtils.getClassLoader()).newInstance();
+                hooks.add(hook);
             } catch (ClassNotFoundException e) {
-                console.printError("Pre Exec Hook Class not found:" + e.getMessage());
+                console.printError(hookConfVar.varname + " Class not found:" + e.getMessage());
                 throw e;
             }
         }
 
-        return pehooks;
+        return hooks;
     }
 
-    private List<Hook> getPostExecHooks() throws Exception {
-        ArrayList<Hook> pehooks = new ArrayList<Hook>();
-        String pestr = conf.getVar(HiveConf.ConfVars.POSTEXECHOOKS);
-        pestr = pestr.trim();
-        if (pestr.equals("")) {
-            return pehooks;
-        }
-
-        String[] peClasses = pestr.split(",");
-
-        for (String peClass : peClasses) {
-            try {
-                pehooks.add((Hook) Class.forName(peClass.trim(), true, JavaUtils.getClassLoader()).newInstance());
-            } catch (ClassNotFoundException e) {
-                console.printError("Post Exec Hook Class not found:" + e.getMessage());
-                throw e;
-            }
-        }
-
-        return pehooks;
-    }
-
-    public int execute() {
+    public int execute() throws CommandNeedRetryException {
         // execute hivesterix plan
         if (hivesterix) {
             hivesterix = false;
@@ -925,6 +1052,9 @@
                 return ret;
         }
 
+        PerfLogger perfLogger = PerfLogger.getPerfLogger();
+        perfLogger.PerfLogBegin(LOG, PerfLogger.DRIVER_EXECUTE);
+
         boolean noName = StringUtils.isEmpty(conf.getVar(HiveConf.ConfVars.HADOOPJOBNAME));
         int maxlen = conf.getIntVar(HiveConf.ConfVars.HIVEJOBNAMELENGTH);
 
@@ -933,6 +1063,10 @@
 
         conf.setVar(HiveConf.ConfVars.HIVEQUERYID, queryId);
         conf.setVar(HiveConf.ConfVars.HIVEQUERYSTRING, queryStr);
+
+        conf.set("mapreduce.workflow.id", "hive_" + queryId);
+        conf.set("mapreduce.workflow.name", queryStr);
+
         maxthreads = HiveConf.getIntVar(conf, HiveConf.ConfVars.EXECPARALLETHREADNUMBER);
 
         try {
@@ -946,14 +1080,23 @@
             }
             resStream = null;
 
-            HookContext hookContext = new HookContext(plan, conf);
+            HookContext hookContext = new HookContext(plan, conf, ctx.getPathToCS());
+            hookContext.setHookType(HookContext.HookType.PRE_EXEC_HOOK);
 
-            for (Hook peh : getPreExecHooks()) {
+            for (Hook peh : getHooks(HiveConf.ConfVars.PREEXECHOOKS)) {
                 if (peh instanceof ExecuteWithHookContext) {
+                    perfLogger.PerfLogBegin(LOG, PerfLogger.PRE_HOOK + peh.getClass().getName());
+
                     ((ExecuteWithHookContext) peh).run(hookContext);
+
+                    perfLogger.PerfLogEnd(LOG, PerfLogger.PRE_HOOK + peh.getClass().getName());
                 } else if (peh instanceof PreExecute) {
+                    perfLogger.PerfLogBegin(LOG, PerfLogger.PRE_HOOK + peh.getClass().getName());
+
                     ((PreExecute) peh).run(SessionState.get(), plan.getInputs(), plan.getOutputs(), ShimLoader
                             .getHadoopShims().getUGIForConf(conf));
+
+                    perfLogger.PerfLogEnd(LOG, PerfLogger.PRE_HOOK + peh.getClass().getName());
                 }
             }
 
@@ -968,32 +1111,36 @@
             }
             String jobname = Utilities.abbreviate(queryStr, maxlen - 6);
 
-            // A runtime that launches runnable tasks as separate Threads
-            // through
+            // A runtime that launches runnable tasks as separate Threads through
             // TaskRunners
             // As soon as a task isRunnable, it is put in a queue
             // At any time, at most maxthreads tasks can be running
-            // The main thread polls the TaskRunners to check if they have
-            // finished.
+            // The main thread polls the TaskRunners to check if they have finished.
 
-            Queue<Task<? extends Serializable>> runnable = new LinkedList<Task<? extends Serializable>>();
+            Queue<Task<? extends Serializable>> runnable = new ConcurrentLinkedQueue<Task<? extends Serializable>>();
             Map<TaskResult, TaskRunner> running = new HashMap<TaskResult, TaskRunner>();
 
             DriverContext driverCxt = new DriverContext(runnable, ctx);
+            ctx.setHDFSCleanup(true);
+
+            SessionState.get().setLastMapRedStatsList(new ArrayList<MapRedStats>());
+            SessionState.get().setStackTraces(new HashMap<String, List<List<String>>>());
+            SessionState.get().setLocalMapRedErrors(new HashMap<String, List<String>>());
 
             // Add root Tasks to runnable
-
             for (Task<? extends Serializable> tsk : plan.getRootTasks()) {
+                // This should never happen, if it does, it's a bug with the potential to produce
+                // incorrect results.
+                assert tsk.getParentTasks() == null || tsk.getParentTasks().isEmpty();
                 driverCxt.addToRunnable(tsk);
             }
 
+            perfLogger.PerfLogEnd(LOG, PerfLogger.TIME_TO_SUBMIT);
             // Loop while you either have tasks running, or tasks queued up
-
             while (running.size() != 0 || runnable.peek() != null) {
                 // Launch upto maxthreads tasks
                 while (runnable.peek() != null && running.size() < maxthreads) {
                     Task<? extends Serializable> tsk = runnable.remove();
-                    console.printInfo("executing task " + tsk.getName());
                     launchTask(tsk, queryId, noName, running, jobname, jobs, driverCxt);
                 }
 
@@ -1005,12 +1152,24 @@
 
                 int exitVal = tskRes.getExitVal();
                 if (exitVal != 0) {
+                    if (tsk.ifRetryCmdWhenFail()) {
+                        if (!running.isEmpty()) {
+                            taskCleanup(running);
+                        }
+                        // in case we decided to run everything in local mode, restore the
+                        // the jobtracker setting to its initial value
+                        ctx.restoreOriginalTracker();
+                        throw new CommandNeedRetryException();
+                    }
                     Task<? extends Serializable> backupTask = tsk.getAndInitBackupTask();
                     if (backupTask != null) {
                         errorMessage = "FAILED: Execution Error, return code " + exitVal + " from "
                                 + tsk.getClass().getName();
+                        ErrorMsg em = ErrorMsg.getErrorMsg(exitVal);
+                        if (em != null) {
+                            errorMessage += ". " + em.getMsg();
+                        }
                         console.printError(errorMessage);
-
                         errorMessage = "ATTEMPT: Execute BackupTask: " + backupTask.getClass().getName();
                         console.printError(errorMessage);
 
@@ -1021,20 +1180,31 @@
                         continue;
 
                     } else {
-                        // TODO: This error messaging is not very informative.
-                        // Fix that.
+                        hookContext.setHookType(HookContext.HookType.ON_FAILURE_HOOK);
+                        // Get all the failure execution hooks and execute them.
+                        for (Hook ofh : getHooks(HiveConf.ConfVars.ONFAILUREHOOKS)) {
+                            perfLogger.PerfLogBegin(LOG, PerfLogger.FAILURE_HOOK + ofh.getClass().getName());
+
+                            ((ExecuteWithHookContext) ofh).run(hookContext);
+
+                            perfLogger.PerfLogEnd(LOG, PerfLogger.FAILURE_HOOK + ofh.getClass().getName());
+                        }
+
                         errorMessage = "FAILED: Execution Error, return code " + exitVal + " from "
                                 + tsk.getClass().getName();
+                        ErrorMsg em = ErrorMsg.getErrorMsg(exitVal);
+                        if (em != null) {
+                            errorMessage += ". " + em.getMsg();
+                        }
                         SQLState = "08S01";
                         console.printError(errorMessage);
-                        if (running.size() != 0) {
-                            taskCleanup();
+                        if (!running.isEmpty()) {
+                            taskCleanup(running);
                         }
-                        // in case we decided to run everything in local mode,
-                        // restore the
+                        // in case we decided to run everything in local mode, restore the
                         // the jobtracker setting to its initial value
                         ctx.restoreOriginalTracker();
-                        return 9;
+                        return exitVal;
                     }
                 }
 
@@ -1047,9 +1217,9 @@
                 if (tsk.getChildTasks() != null) {
                     for (Task<? extends Serializable> child : tsk.getChildTasks()) {
                         // hivesterix: don't check launchable condition
-                        // if (DriverContext.isLaunchable(child)) {
+                        //if(DriverContext.isLaunchable(tsk)){
                         driverCxt.addToRunnable(child);
-                        // }
+                        //}
                     }
                 }
             }
@@ -1059,8 +1229,7 @@
             ctx.restoreOriginalTracker();
 
             // remove incomplete outputs.
-            // Some incomplete outputs may be added at the beginning, for eg:
-            // for dynamic partitions.
+            // Some incomplete outputs may be added at the beginning, for eg: for dynamic partitions.
             // remove them
             HashSet<WriteEntity> remOutputs = new HashSet<WriteEntity>();
             for (WriteEntity output : plan.getOutputs()) {
@@ -1073,15 +1242,24 @@
                 plan.getOutputs().remove(output);
             }
 
+            hookContext.setHookType(HookContext.HookType.POST_EXEC_HOOK);
             // Get all the post execution hooks and execute them.
-            for (Hook peh : getPostExecHooks()) {
+            for (Hook peh : getHooks(HiveConf.ConfVars.POSTEXECHOOKS)) {
                 if (peh instanceof ExecuteWithHookContext) {
+                    perfLogger.PerfLogBegin(LOG, PerfLogger.POST_HOOK + peh.getClass().getName());
+
                     ((ExecuteWithHookContext) peh).run(hookContext);
+
+                    perfLogger.PerfLogEnd(LOG, PerfLogger.POST_HOOK + peh.getClass().getName());
                 } else if (peh instanceof PostExecute) {
+                    perfLogger.PerfLogBegin(LOG, PerfLogger.POST_HOOK + peh.getClass().getName());
+
                     ((PostExecute) peh)
                             .run(SessionState.get(), plan.getInputs(), plan.getOutputs(),
                                     (SessionState.get() != null ? SessionState.get().getLineageState().getLineageInfo()
                                             : null), ShimLoader.getHadoopShims().getUGIForConf(conf));
+
+                    perfLogger.PerfLogEnd(LOG, PerfLogger.POST_HOOK + peh.getClass().getName());
                 }
             }
 
@@ -1089,7 +1267,10 @@
                 SessionState.get().getHiveHistory().setQueryProperty(queryId, Keys.QUERY_RET_CODE, String.valueOf(0));
                 SessionState.get().getHiveHistory().printRowCount(queryId);
             }
+        } catch (CommandNeedRetryException e) {
+            throw e;
         } catch (Exception e) {
+            ctx.restoreOriginalTracker();
             if (SessionState.get() != null) {
                 SessionState.get().getHiveHistory().setQueryProperty(queryId, Keys.QUERY_RET_CODE, String.valueOf(12));
             }
@@ -1105,6 +1286,18 @@
             if (noName) {
                 conf.setVar(HiveConf.ConfVars.HADOOPJOBNAME, "");
             }
+            perfLogger.PerfLogEnd(LOG, PerfLogger.DRIVER_EXECUTE);
+
+            if (SessionState.get().getLastMapRedStatsList() != null
+                    && SessionState.get().getLastMapRedStatsList().size() > 0) {
+                long totalCpu = 0;
+                console.printInfo("MapReduce Jobs Launched: ");
+                for (int i = 0; i < SessionState.get().getLastMapRedStatsList().size(); i++) {
+                    console.printInfo("Job " + i + ": " + SessionState.get().getLastMapRedStatsList().get(i));
+                    totalCpu += SessionState.get().getLastMapRedStatsList().get(i).getCpuMSec();
+                }
+                console.printInfo("Total MapReduce CPU Time Spent: " + Utilities.formatMsecToStr(totalCpu));
+            }
         }
         plan.setDone();
 
@@ -1134,14 +1327,12 @@
      *            name of the task, if it is a map-reduce job
      * @param jobs
      *            number of map-reduce jobs
-     * @param curJobNo
-     *            the sequential number of the next map-reduce job
-     * @return the updated number of last the map-reduce job launched
+     * @param cxt
+     *            the driver context
      */
 
     public void launchTask(Task<? extends Serializable> tsk, String queryId, boolean noName,
             Map<TaskResult, TaskRunner> running, String jobname, int jobs, DriverContext cxt) {
-
         if (SessionState.get() != null) {
             SessionState.get().getHiveHistory().startTask(queryId, tsk, tsk.getClass().getName());
         }
@@ -1149,6 +1340,8 @@
             if (noName) {
                 conf.setVar(HiveConf.ConfVars.HADOOPJOBNAME, jobname + "(" + tsk.getId() + ")");
             }
+            conf.set("mapreduce.workflow.node.name", tsk.getId());
+            Utilities.setWorkflowAdjacencies(conf, plan);
             cxt.incCurJobNo(1);
             console.printInfo("Launching Job " + cxt.getCurJobNo() + " out of " + jobs);
         }
@@ -1156,7 +1349,13 @@
         TaskResult tskRes = new TaskResult();
         TaskRunner tskRun = new TaskRunner(tsk, tskRes);
 
-        // HiveConf.getBoolVar(conf, HiveConf.ConfVars.EXECPARALLEL) &&
+        // Launch Task
+        //if (HiveConf.getBoolVar(conf, HiveConf.ConfVars.EXECPARALLEL) && tsk.isMapRedTask()) {
+        // Launch it in the parallel mode, as a separate thread only for MR tasks
+        //  tskRun.start();
+        //} else {
+        //  tskRun.runSequential();
+        //}
         // Launch Task: hivesterix tweak
         if (tsk instanceof MapRedTask || tsk instanceof StatsTask) {
             // Launch it in the parallel mode, as a separate thread only for MR
@@ -1169,11 +1368,27 @@
             if (crs instanceof ConditionalResolverMergeFiles) {
                 tskRes.setRunning(false);
                 tskRes.setExitVal(0);
-
-                List<Task<? extends Serializable>> children = condTask.getListTasks();
-                for (Task<? extends Serializable> child : children)
-                    if (child instanceof MapRedTask)
-                        cxt.addToRunnable(child);
+                if (!executedConditionalTsks.contains(tsk)) {
+                    List<Task<? extends Serializable>> children = condTask.getListTasks();
+                    Task<? extends Serializable> selectedBranch = null;
+                    for (Task<? extends Serializable> branch : children) {
+                        if (branch instanceof MoveTask) {
+                            selectedBranch = branch;
+                            break;
+                        }
+                    }
+                    if (selectedBranch == null) {
+                        for (int i = children.size() - 1; i >= 0; i--) {
+                            Task<? extends Serializable> child = children.get(i);
+                            if (child instanceof MapRedTask) {
+                                selectedBranch = child;
+                                break;
+                            }
+                        }
+                    }
+                    executedConditionalTsks.add(tsk);
+                    cxt.addToRunnable(selectedBranch);
+                }
             }
         } else {
             tskRun.runSequential();
@@ -1185,12 +1400,18 @@
     /**
      * Cleans up remaining tasks in case of failure
      */
-
-    public void taskCleanup() {
-        // The currently existing Shutdown hooks will be automatically called,
-        // killing the map-reduce processes.
-        // The non MR processes will be killed as well.
-        System.exit(9);
+    public void taskCleanup(Map<TaskResult, TaskRunner> running) {
+        for (Map.Entry<TaskResult, TaskRunner> entry : running.entrySet()) {
+            if (entry.getKey().isRunning()) {
+                Task<?> task = entry.getValue().getTask();
+                try {
+                    task.shutdown();
+                } catch (Exception e) {
+                    console.printError("Exception on shutting down task " + task.getId() + ": " + e);
+                }
+            }
+        }
+        running.clear();
     }
 
     /**
@@ -1214,7 +1435,7 @@
             // In this loop, nothing was found
             // Sleep 10 seconds and restart
             try {
-                Thread.sleep(sleeptime);
+                Thread.sleep(SLEEP_TIME);
             } catch (InterruptedException ie) {
                 // Do Nothing
                 ;
@@ -1223,7 +1444,7 @@
         }
     }
 
-    public boolean getResults(ArrayList<String> res) throws IOException {
+    public boolean getResults(ArrayList<String> res) throws IOException, CommandNeedRetryException {
         if (plan != null && plan.getFetchTask() != null) {
             FetchTask ft = plan.getFetchTask();
             ft.setMaxRows(maxRows);
@@ -1276,6 +1497,14 @@
         return true;
     }
 
+    public int getTryCount() {
+        return tryCount;
+    }
+
+    public void setTryCount(int tryCount) {
+        this.tryCount = tryCount;
+    }
+
     public int close() {
         try {
             if (plan != null) {
@@ -1308,18 +1537,21 @@
     }
 
     public void destroy() {
-        releaseLocks();
+        if (ctx != null) {
+            releaseLocks(ctx.getHiveLocks());
+        }
+
+        if (hiveLockMgr != null) {
+            try {
+                hiveLockMgr.close();
+            } catch (LockException e) {
+                LOG.warn("Exception in closing hive lock manager. "
+                        + org.apache.hadoop.util.StringUtils.stringifyException(e));
+            }
+        }
     }
 
     public org.apache.hadoop.hive.ql.plan.api.Query getQueryPlan() throws IOException {
         return plan.getQueryPlan();
     }
-
-    public int getTryCount() {
-        return tryCount;
-    }
-
-    public void setTryCount(int tryCount) {
-        this.tryCount = tryCount;
-    }
 }
diff --git a/hivesterix/hivesterix-dist/src/main/java/org/apache/hadoop/hive/ql/udf/generic/GenericUDAFCount.java b/hivesterix/hivesterix-dist/src/main/java/org/apache/hadoop/hive/ql/udf/generic/GenericUDAFCount.java
index 2d5191d..1b96259 100644
--- a/hivesterix/hivesterix-dist/src/main/java/org/apache/hadoop/hive/ql/udf/generic/GenericUDAFCount.java
+++ b/hivesterix/hivesterix-dist/src/main/java/org/apache/hadoop/hive/ql/udf/generic/GenericUDAFCount.java
@@ -68,6 +68,7 @@
     @Override
     public GenericUDAFEvaluator getEvaluator(GenericUDAFParameterInfo paramInfo) throws SemanticException {
 
+        @SuppressWarnings("deprecation")
         TypeInfo[] parameters = paramInfo.getParameters();
 
         if (parameters.length == 0) {
diff --git a/hivesterix/hivesterix-dist/src/main/java/org/apache/hadoop/hive/serde2/typeinfo/TypeInfoFactory.java b/hivesterix/hivesterix-dist/src/main/java/org/apache/hadoop/hive/serde2/typeinfo/TypeInfoFactory.java
index 0fea4b9..e26f477 100644
--- a/hivesterix/hivesterix-dist/src/main/java/org/apache/hadoop/hive/serde2/typeinfo/TypeInfoFactory.java
+++ b/hivesterix/hivesterix-dist/src/main/java/org/apache/hadoop/hive/serde2/typeinfo/TypeInfoFactory.java
@@ -36,7 +36,7 @@
 import java.util.List;
 import java.util.concurrent.ConcurrentHashMap;
 
-import org.apache.hadoop.hive.serde.Constants;
+import org.apache.hadoop.hive.serde.serdeConstants;
 import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorUtils;
 
 /**
@@ -65,15 +65,18 @@
         return result;
     }
 
-    public static final TypeInfo voidTypeInfo = getPrimitiveTypeInfo(Constants.VOID_TYPE_NAME);
-    public static final TypeInfo booleanTypeInfo = getPrimitiveTypeInfo(Constants.BOOLEAN_TYPE_NAME);
-    public static final TypeInfo intTypeInfo = getPrimitiveTypeInfo(Constants.INT_TYPE_NAME);
-    public static final TypeInfo longTypeInfo = getPrimitiveTypeInfo(Constants.BIGINT_TYPE_NAME);
-    public static final TypeInfo stringTypeInfo = getPrimitiveTypeInfo(Constants.STRING_TYPE_NAME);
-    public static final TypeInfo floatTypeInfo = getPrimitiveTypeInfo(Constants.FLOAT_TYPE_NAME);
-    public static final TypeInfo doubleTypeInfo = getPrimitiveTypeInfo(Constants.DOUBLE_TYPE_NAME);
-    public static final TypeInfo byteTypeInfo = getPrimitiveTypeInfo(Constants.TINYINT_TYPE_NAME);
-    public static final TypeInfo shortTypeInfo = getPrimitiveTypeInfo(Constants.SMALLINT_TYPE_NAME);
+    public static final TypeInfo voidTypeInfo = getPrimitiveTypeInfo(serdeConstants.VOID_TYPE_NAME);
+    public static final TypeInfo booleanTypeInfo = getPrimitiveTypeInfo(serdeConstants.BOOLEAN_TYPE_NAME);
+    public static final TypeInfo intTypeInfo = getPrimitiveTypeInfo(serdeConstants.INT_TYPE_NAME);
+    public static final TypeInfo longTypeInfo = getPrimitiveTypeInfo(serdeConstants.BIGINT_TYPE_NAME);
+    public static final TypeInfo stringTypeInfo = getPrimitiveTypeInfo(serdeConstants.STRING_TYPE_NAME);
+    public static final TypeInfo floatTypeInfo = getPrimitiveTypeInfo(serdeConstants.FLOAT_TYPE_NAME);
+    public static final TypeInfo doubleTypeInfo = getPrimitiveTypeInfo(serdeConstants.DOUBLE_TYPE_NAME);
+    public static final TypeInfo byteTypeInfo = getPrimitiveTypeInfo(serdeConstants.TINYINT_TYPE_NAME);
+    public static final TypeInfo shortTypeInfo = getPrimitiveTypeInfo(serdeConstants.SMALLINT_TYPE_NAME);
+    public static final TypeInfo timestampTypeInfo = getPrimitiveTypeInfo(serdeConstants.TIMESTAMP_TYPE_NAME);
+    public static final TypeInfo binaryTypeInfo = getPrimitiveTypeInfo(serdeConstants.BINARY_TYPE_NAME);
+    public static final TypeInfo decimalTypeInfo = getPrimitiveTypeInfo(serdeConstants.DECIMAL_TYPE_NAME);
 
     public static final TypeInfo unknownTypeInfo = getPrimitiveTypeInfo("unknown");
 
diff --git a/hivesterix/hivesterix-dist/src/main/resources/conf/hive-default.xml b/hivesterix/hivesterix-dist/src/main/resources/conf/hive-default.xml
deleted file mode 100644
index 23a842a..0000000
--- a/hivesterix/hivesterix-dist/src/main/resources/conf/hive-default.xml
+++ /dev/null
@@ -1,773 +0,0 @@
-<?xml version="1.0"?>
-<!--
- ! Copyright 2009-2013 by The Regents of the University of California
- ! Licensed under the Apache License, Version 2.0 (the "License");
- ! you may not use this file except in compliance with the License.
- ! you may obtain a copy of the License from
- ! 
- !     http://www.apache.org/licenses/LICENSE-2.0
- ! 
- ! Unless required by applicable law or agreed to in writing, software
- ! distributed under the License is distributed on an "AS IS" BASIS,
- ! WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- ! See the License for the specific language governing permissions and
- ! limitations under the License.
- !-->
-<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
-
-<configuration>
-
-	<!-- Hive Configuration can either be stored in this file or in the hadoop 
-		configuration files -->
-	<!-- that are implied by Hadoop setup variables. -->
-	<!-- Aside from Hadoop setup variables - this file is provided as a convenience 
-		so that Hive -->
-	<!-- users do not have to edit hadoop configuration files (that may be managed 
-		as a centralized -->
-	<!-- resource). -->
-
-	<!-- Hive Execution Parameters -->
-	<property>
-		<name>mapred.reduce.tasks</name>
-		<value>-1</value>
-		<description>The default number of reduce tasks per job. Typically set
-			to a prime close to the number of available hosts. Ignored when
-			mapred.job.tracker is "local". Hadoop set this to 1 by default,
-			whereas hive uses -1 as its default value.
-			By setting this property to -1, Hive will automatically figure out what
-			should be the number of reducers.
-        	</description>
-        </property>
-
-        <property>
-		<name>hive.hyracks.connectorpolicy</name>
-		<value>PIPELINING</value>
-        </property>
-
-	<property>
-		<name>hive.hyracks.parrallelism</name>
-		<value>4</value>
-	</property>
-
-	<property>
-		<name>hive.algebricks.groupby.external</name>
-		<value>true</value>
-	</property>
-	
-	<property>
-		<name>hive.algebricks.groupby.external.memory</name>
-		<value>33554432</value>
-	</property>
-	
-	<property>
-		<name>hive.algebricks.sort.memory</name>
-		<value>33554432</value>
-	</property>
-
-	<property>
-		<name>hive.exec.reducers.bytes.per.reducer</name>
-		<value>1000000000</value>
-		<description>size per reducer.The default is 1G, i.e if the input size
-			is 10G, it will use 10 reducers.</description>
-	</property>
-
-	<property>
-		<name>hive.exec.reducers.max</name>
-		<value>999</value>
-		<description>max number of reducers will be used. If the one
-			specified in the configuration parameter mapred.reduce.tasks is
-			negative, hive will use this one as the max number of reducers when
-			automatically determine number of reducers.</description>
-	</property>
-
-	<property>
-		<name>hive.exec.scratchdir</name>
-		<value>/hive-${user.name}</value>
-		<description>Scratch space for Hive jobs</description>
-	</property>
-
-	<property>
-		<name>hive.test.mode</name>
-		<value>false</value>
-		<description>whether hive is running in test mode. If yes, it turns on
-			sampling and prefixes the output tablename</description>
-	</property>
-
-	<property>
-		<name>hive.test.mode.prefix</name>
-		<value>test_</value>
-		<description>if hive is running in test mode, prefixes the output
-			table by this string</description>
-	</property>
-
-	<!-- If the input table is not bucketed, the denominator of the tablesample 
-		is determinied by the parameter below -->
-	<!-- For example, the following query: -->
-	<!-- INSERT OVERWRITE TABLE dest -->
-	<!-- SELECT col1 from src -->
-	<!-- would be converted to -->
-	<!-- INSERT OVERWRITE TABLE test_dest -->
-	<!-- SELECT col1 from src TABLESAMPLE (BUCKET 1 out of 32 on rand(1)) -->
-	<property>
-		<name>hive.test.mode.samplefreq</name>
-		<value>32</value>
-		<description>if hive is running in test mode and table is not
-			bucketed, sampling frequency</description>
-	</property>
-
-	<property>
-		<name>hive.test.mode.nosamplelist</name>
-		<value></value>
-		<description>if hive is running in test mode, dont sample the above
-			comma seperated list of tables</description>
-	</property>
-
-	<property>
-		<name>hive.metastore.local</name>
-		<value>true</value>
-		<description>controls whether to connect to remove metastore server or
-			open a new metastore server in Hive Client JVM</description>
-	</property>
-
-	<property>
-		<name>javax.jdo.option.ConnectionURL</name>
-		<value>jdbc:derby:;databaseName=metastore_db;create=true</value>
-		<description>JDBC connect string for a JDBC metastore</description>
-	</property>
-
-	<property>
-		<name>javax.jdo.option.ConnectionDriverName</name>
-		<value>org.apache.derby.jdbc.EmbeddedDriver</value>
-		<description>Driver class name for a JDBC metastore</description>
-	</property>
-
-	<property>
-		<name>javax.jdo.PersistenceManagerFactoryClass</name>
-		<value>org.datanucleus.jdo.JDOPersistenceManagerFactory</value>
-		<description>class implementing the jdo persistence</description>
-	</property>
-
-	<property>
-		<name>datanucleus.connectionPoolingType</name>
-		<value>DBCP</value>
-		<description>Uses a DBCP connection pool for JDBC metastore
-		</description>
-	</property>
-
-	<property>
-		<name>javax.jdo.option.DetachAllOnCommit</name>
-		<value>true</value>
-		<description>detaches all objects from session so that they can be
-			used after transaction is committed</description>
-	</property>
-
-	<property>
-		<name>javax.jdo.option.NonTransactionalRead</name>
-		<value>true</value>
-		<description>reads outside of transactions</description>
-	</property>
-
-	<property>
-		<name>javax.jdo.option.ConnectionUserName</name>
-		<value>APP</value>
-		<description>username to use against metastore database</description>
-	</property>
-
-	<property>
-		<name>javax.jdo.option.ConnectionPassword</name>
-		<value>mine</value>
-		<description>password to use against metastore database</description>
-	</property>
-
-	<property>
-		<name>datanucleus.validateTables</name>
-		<value>false</value>
-		<description>validates existing schema against code. turn this on if
-			you want to verify existing schema </description>
-	</property>
-
-	<property>
-		<name>datanucleus.validateColumns</name>
-		<value>false</value>
-		<description>validates existing schema against code. turn this on if
-			you want to verify existing schema </description>
-	</property>
-
-	<property>
-		<name>datanucleus.validateConstraints</name>
-		<value>false</value>
-		<description>validates existing schema against code. turn this on if
-			you want to verify existing schema </description>
-	</property>
-
-	<property>
-		<name>datanucleus.storeManagerType</name>
-		<value>rdbms</value>
-		<description>metadata store type</description>
-	</property>
-
-	<property>
-		<name>datanucleus.autoCreateSchema</name>
-		<value>true</value>
-		<description>creates necessary schema on a startup if one doesn't
-			exist. set this to false, after creating it once</description>
-	</property>
-
-	<property>
-		<name>datanucleus.autoStartMechanismMode</name>
-		<value>checked</value>
-		<description>throw exception if metadata tables are incorrect
-		</description>
-	</property>
-
-	<property>
-		<name>datanucleus.transactionIsolation</name>
-		<value>read-committed</value>
-		<description>Default transaction isolation level for identity
-			generation. </description>
-	</property>
-
-	<property>
-		<name>datanucleus.cache.level2</name>
-		<value>false</value>
-		<description>Use a level 2 cache. Turn this off if metadata is changed
-			independently of hive metastore server</description>
-	</property>
-
-	<property>
-		<name>datanucleus.cache.level2.type</name>
-		<value>SOFT</value>
-		<description>SOFT=soft reference based cache, WEAK=weak reference
-			based cache.</description>
-	</property>
-
-	<property>
-		<name>datanucleus.identifierFactory</name>
-		<value>datanucleus</value>
-		<description>Name of the identifier factory to use when generating
-			table/column names etc. 'datanucleus' is used for backward
-			compatibility</description>
-	</property>
-
-	<property>
-		<name>hive.metastore.warehouse.dir</name>
-		<value>/user/hivesterix</value>
-		<description>location of default database for the warehouse
-		</description>
-	</property>
-
-	<property>
-		<name>hive.metastore.connect.retries</name>
-		<value>5</value>
-		<description>Number of retries while opening a connection to metastore
-		</description>
-	</property>
-
-	<property>
-		<name>hive.metastore.rawstore.impl</name>
-		<value>org.apache.hadoop.hive.metastore.ObjectStore</value>
-		<description>Name of the class that implements
-			org.apache.hadoop.hive.metastore.rawstore interface. This class is
-			used to store and retrieval of raw metadata objects such as table,
-			database</description>
-	</property>
-
-	<property>
-		<name>hive.default.fileformat</name>
-		<value>TextFile</value>
-		<description>Default file format for CREATE TABLE statement. Options
-			are TextFile and SequenceFile. Users can explicitly say CREATE TABLE
-			... STORED AS &lt;TEXTFILE|SEQUENCEFILE&gt; to override</description>
-	</property>
-
-	<property>
-		<name>hive.fileformat.check</name>
-		<value>true</value>
-		<description>Whether to check file format or not when loading data
-			files</description>
-	</property>
-
-	<property>
-		<name>hive.map.aggr</name>
-		<value>true</value>
-		<description>Whether to use map-side aggregation in Hive Group By
-			queries</description>
-	</property>
-
-	<property>
-		<name>hive.groupby.skewindata</name>
-		<value>false</value>
-		<description>Whether there is skew in data to optimize group by
-			queries</description>
-	</property>
-
-	<property>
-		<name>hive.groupby.mapaggr.checkinterval</name>
-		<value>100000</value>
-		<description>Number of rows after which size of the grouping
-			keys/aggregation classes is performed</description>
-	</property>
-
-	<property>
-		<name>hive.mapred.local.mem</name>
-		<value>0</value>
-		<description>For local mode, memory of the mappers/reducers
-		</description>
-	</property>
-
-	<property>
-		<name>hive.map.aggr.hash.percentmemory</name>
-		<value>0.5</value>
-		<description>Portion of total memory to be used by map-side grup
-			aggregation hash table</description>
-	</property>
-
-	<property>
-		<name>hive.map.aggr.hash.min.reduction</name>
-		<value>0.5</value>
-		<description>Hash aggregation will be turned off if the ratio between
-			hash
-			table size and input rows is bigger than this number. Set to 1 to make
-			sure
-			hash aggregation is never turned off.</description>
-	</property>
-
-	<property>
-		<name>hive.optimize.cp</name>
-		<value>true</value>
-		<description>Whether to enable column pruner</description>
-	</property>
-
-	<property>
-		<name>hive.optimize.ppd</name>
-		<value>true</value>
-		<description>Whether to enable predicate pushdown</description>
-	</property>
-
-	<property>
-		<name>hive.optimize.pruner</name>
-		<value>true</value>
-		<description>Whether to enable the new partition pruner which depends
-			on predicate pushdown. If this is disabled,
-			the old partition pruner which is based on AST will be enabled.
-		</description>
-	</property>
-
-	<property>
-		<name>hive.optimize.groupby</name>
-		<value>true</value>
-		<description>Whether to enable the bucketed group by from bucketed
-			partitions/tables.</description>
-	</property>
-
-	<property>
-		<name>hive.join.emit.interval</name>
-		<value>1000</value>
-		<description>How many rows in the right-most join operand Hive should
-			buffer before emitting the join result. </description>
-	</property>
-
-	<property>
-		<name>hive.join.cache.size</name>
-		<value>25000</value>
-		<description>How many rows in the joining tables (except the streaming
-			table) should be cached in memory. </description>
-	</property>
-
-	<property>
-		<name>hive.mapjoin.bucket.cache.size</name>
-		<value>100</value>
-		<description>How many values in each keys in the map-joined table
-			should be cached in memory. </description>
-	</property>
-
-	<property>
-		<name>hive.mapjoin.maxsize</name>
-		<value>100000</value>
-		<description>Maximum # of rows of the small table that can be handled
-			by map-side join. If the size is reached and hive.task.progress is
-			set, a fatal error counter is set and the job will be killed.
-		</description>
-	</property>
-
-	<property>
-		<name>hive.mapjoin.cache.numrows</name>
-		<value>25000</value>
-		<description>How many rows should be cached by jdbm for map join.
-		</description>
-	</property>
-
-	<property>
-		<name>hive.optimize.skewjoin</name>
-		<value>false</value>
-		<description>Whether to enable skew join optimization. </description>
-	</property>
-
-	<property>
-		<name>hive.skewjoin.key</name>
-		<value>100000</value>
-		<description>Determine if we get a skew key in join. If we see more
-			than the specified number of rows with the same key in join operator,
-			we think the key as a skew join key. </description>
-	</property>
-
-	<property>
-		<name>hive.skewjoin.mapjoin.map.tasks</name>
-		<value>10000</value>
-		<description> Determine the number of map task used in the follow up
-			map join job
-			for a skew join. It should be used together with
-			hive.skewjoin.mapjoin.min.split
-			to perform a fine grained control.</description>
-	</property>
-
-	<property>
-		<name>hive.skewjoin.mapjoin.min.split</name>
-		<value>33554432</value>
-		<description> Determine the number of map task at most used in the
-			follow up map join job
-			for a skew join by specifying the minimum split size. It should be used
-			together with
-			hive.skewjoin.mapjoin.map.tasks to perform a fine grained control.</description>
-	</property>
-
-	<property>
-		<name>hive.mapred.mode</name>
-		<value>nonstrict</value>
-		<description>The mode in which the hive operations are being
-			performed. In strict mode, some risky queries are not allowed to run
-		</description>
-	</property>
-
-	<property>
-		<name>hive.exec.script.maxerrsize</name>
-		<value>100000</value>
-		<description>Maximum number of bytes a script is allowed to emit to
-			standard error (per map-reduce task). This prevents runaway scripts
-			from filling logs partitions to capacity </description>
-	</property>
-
-	<property>
-		<name>hive.exec.script.allow.partial.consumption</name>
-		<value>false</value>
-		<description> When enabled, this option allows a user script to exit
-			successfully without consuming all the data from the standard input.
-		</description>
-	</property>
-
-	<property>
-		<name>hive.script.operator.id.env.var</name>
-		<value>HIVE_SCRIPT_OPERATOR_ID</value>
-		<description> Name of the environment variable that holds the unique
-			script operator ID in the user's transform function (the custom
-			mapper/reducer that the user has specified in the query)
-		</description>
-	</property>
-
-	<property>
-		<name>hive.exec.compress.output</name>
-		<value>false</value>
-		<description> This controls whether the final outputs of a query (to a
-			local/hdfs file or a hive table) is compressed. The compression codec
-			and other options are determined from hadoop config variables
-			mapred.output.compress* </description>
-	</property>
-
-	<property>
-		<name>hive.exec.compress.intermediate</name>
-		<value>false</value>
-		<description> This controls whether intermediate files produced by
-			hive between multiple map-reduce jobs are compressed. The compression
-			codec and other options are determined from hadoop config variables
-			mapred.output.compress* </description>
-	</property>
-
-	<property>
-		<name>hive.exec.parallel</name>
-		<value>false</value>
-		<description>Whether to execute jobs in parallel</description>
-	</property>
-
-	<property>
-		<name>hive.exec.parallel.thread.number</name>
-		<value>8</value>
-		<description>How many jobs at most can be executed in parallel
-		</description>
-	</property>
-
-	<property>
-		<name>hive.hwi.war.file</name>
-		<value>lib\hive-hwi-0.7.0.war</value>
-		<description>This sets the path to the HWI war file, relative to
-			${HIVE_HOME}. </description>
-	</property>
-
-	<property>
-		<name>hive.hwi.listen.host</name>
-		<value>0.0.0.0</value>
-		<description>This is the host address the Hive Web Interface will
-			listen on</description>
-	</property>
-
-	<property>
-		<name>hive.hwi.listen.port</name>
-		<value>9999</value>
-		<description>This is the port the Hive Web Interface will listen on
-		</description>
-	</property>
-
-	<property>
-		<name>hive.exec.pre.hooks</name>
-		<value></value>
-		<description>Pre Execute Hook for Tests</description>
-	</property>
-
-	<property>
-		<name>hive.merge.mapfiles</name>
-		<value>true</value>
-		<description>Merge small files at the end of a map-only job
-		</description>
-	</property>
-
-	<property>
-		<name>hive.merge.mapredfiles</name>
-		<value>false</value>
-		<description>Merge small files at the end of a map-reduce job
-		</description>
-	</property>
-
-	<property>
-		<name>hive.heartbeat.interval</name>
-		<value>1000</value>
-		<description>Send a heartbeat after this interval - used by mapjoin
-			and filter operators</description>
-	</property>
-
-	<property>
-		<name>hive.merge.size.per.task</name>
-		<value>256000000</value>
-		<description>Size of merged files at the end of the job</description>
-	</property>
-
-	<property>
-		<name>hive.merge.size.smallfiles.avgsize</name>
-		<value>16000000</value>
-		<description>When the average output file size of a job is less than
-			this number, Hive will start an additional map-reduce job to merge
-			the output files into bigger files. This is only done for map-only
-			jobs if hive.merge.mapfiles is true, and for map-reduce jobs if
-			hive.merge.mapredfiles is true.</description>
-	</property>
-
-	<property>
-		<name>hive.script.auto.progress</name>
-		<value>false</value>
-		<description>Whether Hive Tranform/Map/Reduce Clause should
-			automatically send progress information to TaskTracker to avoid the
-			task getting killed because of inactivity. Hive sends progress
-			information when the script is outputting to stderr. This option
-			removes the need of periodically producing stderr messages, but users
-			should be cautious because this may prevent infinite loops in the
-			scripts to be killed by TaskTracker.  </description>
-	</property>
-
-	<property>
-		<name>hive.script.serde</name>
-		<value>org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe</value>
-		<description>The default serde for trasmitting input data to and
-			reading output data from the user scripts. </description>
-	</property>
-
-	<property>
-		<name>hive.script.recordreader</name>
-		<value>org.apache.hadoop.hive.ql.exec.TextRecordReader</value>
-		<description>The default record reader for reading data from the user
-			scripts. </description>
-	</property>
-
-	<property>
-		<name>hive.script.recordwriter</name>
-		<value>org.apache.hadoop.hive.ql.exec.TextRecordWriter</value>
-		<description>The default record writer for writing data to the user
-			scripts. </description>
-	</property>
-
-	<property>
-		<name>hive.input.format</name>
-		<value>org.apache.hadoop.hive.ql.io.HiveInputFormat</value>
-		<description>The default input format, if it is not specified, the
-			system assigns it. It is set to HiveInputFormat for hadoop versions
-			17, 18 and 19, whereas it is set to CombinedHiveInputFormat for
-			hadoop 20. The user can always overwrite it - if there is a bug in
-			CombinedHiveInputFormat, it can always be manually set to
-			HiveInputFormat. </description>
-	</property>
-
-	<property>
-		<name>hive.udtf.auto.progress</name>
-		<value>false</value>
-		<description>Whether Hive should automatically send progress
-			information to TaskTracker when using UDTF's to prevent the task
-			getting killed because of inactivity. Users should be cautious
-			because this may prevent TaskTracker from killing tasks with infinte
-			loops.  </description>
-	</property>
-
-	<property>
-		<name>hive.mapred.reduce.tasks.speculative.execution</name>
-		<value>true</value>
-		<description>Whether speculative execution for reducers should be
-			turned on. </description>
-	</property>
-
-	<property>
-		<name>hive.exec.counters.pull.interval</name>
-		<value>1000</value>
-		<description>The interval with which to poll the JobTracker for the
-			counters the running job. The smaller it is the more load there will
-			be on the jobtracker, the higher it is the less granular the caught
-			will be.</description>
-	</property>
-
-	<property>
-		<name>hive.enforce.bucketing</name>
-		<value>false</value>
-		<description>Whether bucketing is enforced. If true, while inserting
-			into the table, bucketing is enforced. </description>
-	</property>
-
-	<property>
-		<name>hive.enforce.sorting</name>
-		<value>false</value>
-		<description>Whether sorting is enforced. If true, while inserting
-			into the table, sorting is enforced. </description>
-	</property>
-
-	<property>
-		<name>hive.metastore.ds.connection.url.hook</name>
-		<value></value>
-		<description>Name of the hook to use for retriving the JDO connection
-			URL. If empty, the value in javax.jdo.option.ConnectionURL is used
-		</description>
-	</property>
-
-	<property>
-		<name>hive.metastore.ds.retry.attempts</name>
-		<value>1</value>
-		<description>The number of times to retry a metastore call if there
-			were a connection error</description>
-	</property>
-
-	<property>
-		<name>hive.metastore.ds.retry.interval</name>
-		<value>1000</value>
-		<description>The number of miliseconds between metastore retry
-			attempts</description>
-	</property>
-
-	<property>
-		<name>hive.metastore.server.min.threads</name>
-		<value>200</value>
-		<description>Minimum number of worker threads in the Thrift server's
-			pool.</description>
-	</property>
-
-	<property>
-		<name>hive.metastore.server.max.threads</name>
-		<value>100000</value>
-		<description>Maximum number of worker threads in the Thrift server's
-			pool.</description>
-	</property>
-
-	<property>
-		<name>hive.metastore.server.tcp.keepalive</name>
-		<value>true</value>
-		<description>Whether to enable TCP keepalive for the metastore server.
-			Keepalive will prevent accumulation of half-open connections.
-		</description>
-	</property>
-
-	<property>
-		<name>hive.optimize.reducededuplication</name>
-		<value>true</value>
-		<description>Remove extra map-reduce jobs if the data is already
-			clustered by the same key which needs to be used again. This should
-			always be set to true. Since it is a new feature, it has been made
-			configurable.</description>
-	</property>
-
-	<property>
-		<name>hive.exec.dynamic.partition</name>
-		<value>false</value>
-		<description>Whether or not to allow dynamic partitions in DML/DDL.
-		</description>
-	</property>
-
-	<property>
-		<name>hive.exec.dynamic.partition.mode</name>
-		<value>strict</value>
-		<description>In strict mode, the user must specify at least one static
-			partition in case the user accidentally overwrites all partitions.
-		</description>
-	</property>
-
-	<property>
-		<name>hive.exec.max.dynamic.partitions</name>
-		<value>1000</value>
-		<description>Maximum number of dynamic partitions allowed to be
-			created in total.</description>
-	</property>
-
-	<property>
-		<name>hive.exec.max.dynamic.partitions.pernode</name>
-		<value>100</value>
-		<description>Maximum number of dynamic partitions allowed to be
-			created in each mapper/reducer node.</description>
-	</property>
-
-	<property>
-		<name>hive.default.partition.name</name>
-		<value>__HIVE_DEFAULT_PARTITION__</value>
-		<description>The default partition name in case the dynamic partition
-			column value is null/empty string or anyother values that cannot be
-			escaped. This value must not contain any special character used in
-			HDFS URI (e.g., ':', '%', '/' etc). The user has to be aware that the
-			dynamic partition value should not contain this value to avoid
-			confusions.</description>
-	</property>
-
-	<property>
-		<name>fs.har.impl</name>
-		<value>org.apache.hadoop.hive.shims.HiveHarFileSystem</value>
-		<description>The implementation for accessing Hadoop Archives. Note
-			that this won't be applicable to Hadoop vers less than 0.20
-		</description>
-	</property>
-
-	<property>
-		<name>hive.archive.enabled</name>
-		<value>false</value>
-		<description>Whether archiving operations are permitted</description>
-	</property>
-
-	<property>
-		<name>hive.archive.har.parentdir.settable</name>
-		<value>false</value>
-		<description>In new Hadoop versions, the parent directory must be set
-			while
-			creating a HAR. Because this functionality is hard to detect with just
-			version
-			numbers, this conf var needs to be set manually.</description>
-	</property>
-
-	<!-- HBase Storage Handler Parameters -->
-
-	<property>
-		<name>hive.hbase.wal.enabled</name>
-		<value>true</value>
-		<description>Whether writes to HBase should be forced to the
-			write-ahead log. Disabling this improves HBase write performance at
-			the risk of lost writes in case of a crash.</description>
-	</property>
-
-</configuration>
diff --git a/hivesterix/hivesterix-dist/src/main/resources/conf/hive-log4j.properties b/hivesterix/hivesterix-dist/src/main/resources/conf/hive-log4j.properties
index eab38a6..6f195f5 100644
--- a/hivesterix/hivesterix-dist/src/main/resources/conf/hive-log4j.properties
+++ b/hivesterix/hivesterix-dist/src/main/resources/conf/hive-log4j.properties
@@ -31,7 +31,7 @@
 #      FATAL, ERROR, WARN, INFO, DEBUG
 #
 #------------------------------------------------------------------------------
-log4j.rootCategory=INFO, S
+log4j.rootCategory=FATAL, S
 
 log4j.logger.com.dappit.Dapper.parser=ERROR
 log4j.logger.org.w3c.tidy=FATAL
diff --git a/hivesterix/hivesterix-dist/src/main/resources/conf/hive-site.xml b/hivesterix/hivesterix-dist/src/main/resources/conf/hive-site.xml
new file mode 100644
index 0000000..ccfcd74
--- /dev/null
+++ b/hivesterix/hivesterix-dist/src/main/resources/conf/hive-site.xml
@@ -0,0 +1,5189 @@
+<?xml version="1.0"?>
+<!-- ! Copyright 2009-2013 by The Regents of the University of California 
+	! Licensed under the Apache License, Version 2.0 (the "License"); ! you may 
+	not use this file except in compliance with the License. ! you may obtain 
+	a copy of the License from ! ! http://www.apache.org/licenses/LICENSE-2.0 
+	! ! Unless required by applicable law or agreed to in writing, software ! 
+	distributed under the License is distributed on an "AS IS" BASIS, ! WITHOUT 
+	WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. ! See the 
+	License for the specific language governing permissions and ! limitations 
+	under the License. ! -->
+<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
+
+<configuration>
+
+	<configuration>
+		<!-- Hivesterix Execution Parameters -->
+		<property>
+			<name>hive.hyracks.connectorpolicy</name>
+			<value>PIPELINING</value>
+		</property>
+
+		<property>
+			<name>hive.hyracks.parrallelism</name>
+			<value>4</value>
+		</property>
+
+		<property>
+			<name>hive.algebricks.groupby.external</name>
+			<value>true</value>
+		</property>
+		
+		<property>
+			<name>hive.algebricks.groupby.external.memory</name>
+			<value>33554432</value>
+		</property>
+
+		<property>
+			<name>hive.algebricks.sort.memory</name>
+			<value>33554432</value>
+		</property>
+		
+		<property>
+            <name>hive.algebricks.framesize</name>
+            <value>32768</value>
+        </property>
+
+		<!-- Hive Execution Parameters -->
+		<property>
+			<name>mapred.reduce.tasks</name>
+			<value>-1</value>
+			<description>The default number of reduce tasks per job. Typically
+				set
+				to a prime close to the number of available hosts. Ignored when
+				mapred.job.tracker is "local". Hadoop set this to 1 by default,
+				whereas hive uses -1 as its default value.
+				By setting this property
+				to -1, Hive will automatically figure out
+				what should be the number
+				of reducers.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.reducers.bytes.per.reducer</name>
+			<value>1000000000</value>
+			<description>size per reducer.The default is 1G, i.e if the input
+				size is 10G, it will use 10 reducers.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.reducers.max</name>
+			<value>999</value>
+			<description>max number of reducers will be used. If the one
+				specified in the configuration parameter mapred.reduce.tasks is
+				negative, hive will use this one as the max number of reducers when
+				automatically determine number of reducers.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.cli.print.header</name>
+			<value>false</value>
+			<description>Whether to print the names of the columns in query
+				output.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.cli.print.current.db</name>
+			<value>false</value>
+			<description>Whether to include the current database in the hive
+				prompt.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.cli.prompt</name>
+			<value>hive</value>
+			<description>Command line prompt configuration value. Other hiveconf
+				can be used in
+				this configuration value. Variable substitution will
+				only be invoked at
+				the hive
+				cli startup.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.cli.pretty.output.num.cols</name>
+			<value>-1</value>
+			<description>The number of columns to use when formatting output
+				generated
+				by the DESCRIBE PRETTY table_name command. If the value of
+				this
+				property
+				is -1, then hive will use the auto-detected terminal
+				width.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.scratchdir</name>
+			<value>/tmp/hive-${user.name}</value>
+			<description>Scratch space for Hive jobs</description>
+		</property>
+
+		<property>
+			<name>hive.exec.local.scratchdir</name>
+			<value>/tmp/${user.name}</value>
+			<description>Local scratch space for Hive jobs</description>
+		</property>
+
+		<property>
+			<name>hive.test.mode</name>
+			<value>false</value>
+			<description>whether hive is running in test mode. If yes, it turns
+				on sampling and prefixes the output tablename
+			</description>
+		</property>
+
+		<property>
+			<name>hive.test.mode.prefix</name>
+			<value>test_</value>
+			<description>if hive is running in test mode, prefixes the output
+				table by this string
+			</description>
+		</property>
+
+		<!-- If the input table is not bucketed, the denominator of the tablesample 
+			is determinied by the parameter below -->
+		<!-- For example, the following query: -->
+		<!-- INSERT OVERWRITE TABLE dest -->
+		<!-- SELECT col1 from src -->
+		<!-- would be converted to -->
+		<!-- INSERT OVERWRITE TABLE test_dest -->
+		<!-- SELECT col1 from src TABLESAMPLE (BUCKET 1 out of 32 on rand(1)) -->
+		<property>
+			<name>hive.test.mode.samplefreq</name>
+			<value>32</value>
+			<description>if hive is running in test mode and table is not
+				bucketed, sampling frequency
+			</description>
+		</property>
+
+		<property>
+			<name>hive.test.mode.nosamplelist</name>
+			<value></value>
+			<description>if hive is running in test mode, dont sample the above
+				comma seperated list of tables
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.uris</name>
+			<value></value>
+			<description>Thrift uri for the remote metastore. Used by metastore
+				client to connect to remote metastore.
+			</description>
+		</property>
+
+		<property>
+			<name>javax.jdo.option.ConnectionURL</name>
+			<value>jdbc:derby:;databaseName=metastore_db;create=true</value>
+			<description>JDBC connect string for a JDBC metastore</description>
+		</property>
+
+		<property>
+			<name>javax.jdo.option.ConnectionDriverName</name>
+			<value>org.apache.derby.jdbc.EmbeddedDriver</value>
+			<description>Driver class name for a JDBC metastore</description>
+		</property>
+
+		<property>
+			<name>javax.jdo.PersistenceManagerFactoryClass</name>
+			<value>org.datanucleus.jdo.JDOPersistenceManagerFactory</value>
+			<description>class implementing the jdo persistence</description>
+		</property>
+
+		<property>
+			<name>javax.jdo.option.DetachAllOnCommit</name>
+			<value>true</value>
+			<description>detaches all objects from session so that they can be
+				used after transaction is committed
+			</description>
+		</property>
+
+		<property>
+			<name>javax.jdo.option.NonTransactionalRead</name>
+			<value>true</value>
+			<description>reads outside of transactions</description>
+		</property>
+
+		<property>
+			<name>javax.jdo.option.ConnectionUserName</name>
+			<value>APP</value>
+			<description>username to use against metastore database</description>
+		</property>
+
+		<property>
+			<name>javax.jdo.option.ConnectionPassword</name>
+			<value>mine</value>
+			<description>password to use against metastore database</description>
+		</property>
+
+		<property>
+			<name>javax.jdo.option.Multithreaded</name>
+			<value>true</value>
+			<description>Set this to true if multiple threads access metastore
+				through JDO concurrently.
+			</description>
+		</property>
+
+		<property>
+			<name>datanucleus.connectionPoolingType</name>
+			<value>DBCP</value>
+			<description>Uses a DBCP connection pool for JDBC metastore
+			</description>
+		</property>
+
+		<property>
+			<name>datanucleus.validateTables</name>
+			<value>false</value>
+			<description>validates existing schema against code. turn this on if
+				you want to verify existing schema
+			</description>
+		</property>
+
+		<property>
+			<name>datanucleus.validateColumns</name>
+			<value>false</value>
+			<description>validates existing schema against code. turn this on if
+				you want to verify existing schema
+			</description>
+		</property>
+
+		<property>
+			<name>datanucleus.validateConstraints</name>
+			<value>false</value>
+			<description>validates existing schema against code. turn this on if
+				you want to verify existing schema
+			</description>
+		</property>
+
+		<property>
+			<name>datanucleus.storeManagerType</name>
+			<value>rdbms</value>
+			<description>metadata store type</description>
+		</property>
+
+		<property>
+			<name>datanucleus.autoCreateSchema</name>
+			<value>true</value>
+			<description>creates necessary schema on a startup if one doesn't
+				exist. set this to false, after creating it once
+			</description>
+		</property>
+
+		<property>
+			<name>datanucleus.autoStartMechanismMode</name>
+			<value>checked</value>
+			<description>throw exception if metadata tables are incorrect
+			</description>
+		</property>
+
+		<property>
+			<name>datanucleus.transactionIsolation</name>
+			<value>read-committed</value>
+			<description>Default transaction isolation level for identity
+				generation.
+			</description>
+		</property>
+
+		<property>
+			<name>datanucleus.cache.level2</name>
+			<value>false</value>
+			<description>Use a level 2 cache. Turn this off if metadata is
+				changed independently of hive metastore server
+			</description>
+		</property>
+
+		<property>
+			<name>datanucleus.cache.level2.type</name>
+			<value>SOFT</value>
+			<description>SOFT=soft reference based cache, WEAK=weak reference
+				based cache.
+			</description>
+		</property>
+
+		<property>
+			<name>datanucleus.identifierFactory</name>
+			<value>datanucleus</value>
+			<description>Name of the identifier factory to use when generating
+				table/column names etc. 'datanucleus' is used for backward
+				compatibility
+			</description>
+		</property>
+
+		<property>
+			<name>datanucleus.plugin.pluginRegistryBundleCheck</name>
+			<value>LOG</value>
+			<description>Defines what happens when plugin bundles are found and
+				are duplicated [EXCEPTION|LOG|NONE]
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.warehouse.dir</name>
+			<value>/user/hive/warehouse</value>
+			<description>location of default database for the warehouse
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.execute.setugi</name>
+			<value>false</value>
+			<description>In unsecure mode, setting this property to true will
+				cause the metastore to execute DFS operations using the client's
+				reported user and group permissions. Note that this property must be
+				set on both the client and server sides. Further note that its best
+				effort. If client sets its to true and server sets it to false,
+				client setting will be ignored.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.event.listeners</name>
+			<value></value>
+			<description>list of comma seperated listeners for metastore events.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.partition.inherit.table.properties</name>
+			<value></value>
+			<description>list of comma seperated keys occurring in table
+				properties which will get inherited to newly created partitions. *
+				implies all the keys will get inherited.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metadata.export.location</name>
+			<value></value>
+			<description>When used in conjunction with the
+				org.apache.hadoop.hive.ql.parse.MetaDataExportListener pre event
+				listener, it is the location to which the metadata will be exported.
+				The default is an empty string, which results in the metadata being
+				exported to the current user's home directory on HDFS.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metadata.move.exported.metadata.to.trash</name>
+			<value></value>
+			<description>When used in conjunction with the
+				org.apache.hadoop.hive.ql.parse.MetaDataExportListener pre event
+				listener, this setting determines if the metadata that is exported
+				will subsequently be moved to the user's trash directory alongside
+				the dropped table data. This ensures that the metadata will be
+				cleaned up along with the dropped table data.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.partition.name.whitelist.pattern</name>
+			<value></value>
+			<description>Partition names will be checked against this regex
+				pattern and rejected if not matched.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.end.function.listeners</name>
+			<value></value>
+			<description>list of comma separated listeners for the end of
+				metastore functions.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.event.expiry.duration</name>
+			<value>0</value>
+			<description>Duration after which events expire from events table (in
+				seconds)
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.event.clean.freq</name>
+			<value>0</value>
+			<description>Frequency at which timer task runs to purge expired
+				events in metastore(in seconds).
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.connect.retries</name>
+			<value>5</value>
+			<description>Number of retries while opening a connection to
+				metastore
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.failure.retries</name>
+			<value>3</value>
+			<description>Number of retries upon failure of Thrift metastore calls
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.client.connect.retry.delay</name>
+			<value>1</value>
+			<description>Number of seconds for the client to wait between
+				consecutive connection attempts
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.client.socket.timeout</name>
+			<value>20</value>
+			<description>MetaStore Client socket timeout in seconds</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.rawstore.impl</name>
+			<value>org.apache.hadoop.hive.metastore.ObjectStore</value>
+			<description>Name of the class that implements
+				org.apache.hadoop.hive.metastore.rawstore interface. This class is
+				used to store and retrieval of raw metadata objects such as table,
+				database
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.batch.retrieve.max</name>
+			<value>300</value>
+			<description>Maximum number of objects (tables/partitions) can be
+				retrieved from metastore in one batch. The higher the number, the
+				less the number of round trips is needed to the Hive metastore
+				server, but it may also cause higher memory requirement at the
+				client side.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.batch.retrieve.table.partition.max</name>
+			<value>1000</value>
+			<description>Maximum number of table partitions that metastore
+				internally retrieves in one batch.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.default.fileformat</name>
+			<value>TextFile</value>
+			<description>Default file format for CREATE TABLE statement. Options
+				are TextFile and SequenceFile. Users can explicitly say CREATE TABLE
+				... STORED AS &lt;TEXTFILE|SEQUENCEFILE&gt; to override
+			</description>
+		</property>
+
+		<property>
+			<name>hive.fileformat.check</name>
+			<value>true</value>
+			<description>Whether to check file format or not when loading data
+				files
+			</description>
+		</property>
+
+		<property>
+			<name>hive.map.aggr</name>
+			<value>true</value>
+			<description>Whether to use map-side aggregation in Hive Group By
+				queries
+			</description>
+		</property>
+
+		<property>
+			<name>hive.groupby.skewindata</name>
+			<value>false</value>
+			<description>Whether there is skew in data to optimize group by
+				queries
+			</description>
+		</property>
+
+		<property>
+			<name>hive.optimize.multigroupby.common.distincts</name>
+			<value>true</value>
+			<description>Whether to optimize a multi-groupby query with the same
+				distinct.
+				Consider a query like:
+
+				from src
+				insert overwrite table dest1
+				select col1, count(distinct colx) group by
+				col1
+				insert overwrite table
+				dest2 select col2, count(distinct colx) group by
+				col2;
+
+				With this
+				parameter set to true, first we spray by the distinct value
+				(colx),
+				and then
+				perform the 2 groups bys. This makes sense if map-side
+				aggregation is
+				turned off. However,
+				with maps-side aggregation, it
+				might be useful in some cases to treat
+				the 2 inserts independently,
+				thereby performing the query above in 2MR jobs instead of 3 (due to
+				spraying by distinct key first).
+				If this parameter is turned off, we
+				dont consider the fact that the
+				distinct key is the same across
+				different MR jobs.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.groupby.mapaggr.checkinterval</name>
+			<value>100000</value>
+			<description>Number of rows after which size of the grouping
+				keys/aggregation classes is performed
+			</description>
+		</property>
+
+		<property>
+			<name>hive.mapred.local.mem</name>
+			<value>0</value>
+			<description>For local mode, memory of the mappers/reducers
+			</description>
+		</property>
+
+		<property>
+			<name>hive.mapjoin.followby.map.aggr.hash.percentmemory</name>
+			<value>0.3</value>
+			<description>Portion of total memory to be used by map-side grup
+				aggregation hash table, when this group by is followed by map join
+			</description>
+		</property>
+
+		<property>
+			<name>hive.map.aggr.hash.force.flush.memory.threshold</name>
+			<value>0.9</value>
+			<description>The max memory to be used by map-side grup aggregation
+				hash table, if the memory usage is higher than this number, force to
+				flush data
+			</description>
+		</property>
+
+		<property>
+			<name>hive.map.aggr.hash.percentmemory</name>
+			<value>0.5</value>
+			<description>Portion of total memory to be used by map-side grup
+				aggregation hash table
+			</description>
+		</property>
+
+		<property>
+			<name>hive.map.aggr.hash.min.reduction</name>
+			<value>0.5</value>
+			<description>Hash aggregation will be turned off if the ratio between
+				hash
+				table size and input rows is bigger than this number. Set to 1
+				to make
+				sure
+				hash aggregation is never turned off.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.optimize.cp</name>
+			<value>true</value>
+			<description>Whether to enable column pruner</description>
+		</property>
+
+		<property>
+			<name>hive.optimize.index.filter</name>
+			<value>false</value>
+			<description>Whether to enable automatic use of indexes</description>
+		</property>
+
+		<property>
+			<name>hive.optimize.index.groupby</name>
+			<value>false</value>
+			<description>Whether to enable optimization of group-by queries using
+				Aggregate indexes.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.optimize.ppd</name>
+			<value>true</value>
+			<description>Whether to enable predicate pushdown</description>
+		</property>
+
+		<property>
+			<name>hive.optimize.ppd.storage</name>
+			<value>true</value>
+			<description>Whether to push predicates down into storage handlers.
+				Ignored when hive.optimize.ppd is false.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.ppd.recognizetransivity</name>
+			<value>true</value>
+			<description>Whether to transitively replicate predicate filters over
+				equijoin conditions.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.optimize.groupby</name>
+			<value>true</value>
+			<description>Whether to enable the bucketed group by from bucketed
+				partitions/tables.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.optimize.skewjoin.compiletime</name>
+			<value>false</value>
+			<description>Whether to create a separate plan for skewed keys for
+				the tables in the join.
+				This is based on the skewed keys stored in
+				the metadata. At compile
+				time, the plan is broken
+				into different
+				joins: one for the skewed keys, and the other for the
+				remaining keys.
+				And then,
+				a union is performed for the 2 joins generated above. So
+				unless the
+				same skewed key is present
+				in both the joined tables, the
+				join for the skewed key will be
+				performed as a map-side join.
+
+				The main
+				difference between this paramater and hive.optimize.skewjoin
+				is that
+				this parameter
+				uses the skew information stored in the metastore to
+				optimize the plan
+				at compile time itself.
+				If there is no skew
+				information in the metadata, this parameter will
+				not have any affect.
+				Both hive.optimize.skewjoin.compiletime and hive.optimize.skewjoin
+				should be set to true.
+				Ideally, hive.optimize.skewjoin should be
+				renamed as
+				hive.optimize.skewjoin.runtime, but not doing
+				so for
+				backward compatibility.
+
+				If the skew information is correctly stored
+				in the metadata,
+				hive.optimize.skewjoin.compiletime
+				would change the
+				query plan to take care of it, and
+				hive.optimize.skewjoin will be a
+				no-op.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.optimize.union.remove</name>
+			<value>false</value>
+			<description>
+				Whether to remove the union and push the operators
+				between union and the
+				filesink above
+				union. This avoids an extra scan
+				of the output by union. This is
+				independently useful for union
+				queries, and specially useful when
+				hive.optimize.skewjoin.compiletime is set
+				to true, since an
+				extra
+				union is inserted.
+
+				The merge is triggered if either of
+				hive.merge.mapfiles or
+				hive.merge.mapredfiles is set to true.
+				If the
+				user has set hive.merge.mapfiles to true and
+				hive.merge.mapredfiles
+				to false, the idea was the
+				number of reducers are few, so the number
+				of files anyway are small.
+				However, with this optimization,
+				we are
+				increasing the number of files possibly by a big margin. So, we
+				merge aggresively.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.mapred.supports.subdirectories</name>
+			<value>false</value>
+			<description>Whether the version of hadoop which is running supports
+				sub-directories for tables/partitions.
+				Many hive optimizations can be
+				applied if the hadoop version supports
+				sub-directories for
+				tables/partitions. It was added by MAPREDUCE-1501
+			</description>
+		</property>
+
+		<property>
+			<name>hive.multigroupby.singlemr</name>
+			<value>true</value>
+			<description>Whether to optimize multi group by query to generate
+				single M/R
+				job plan. If the multi group by query has common group by
+				keys, it will
+				be
+				optimized to generate single M/R job.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.map.groupby.sorted</name>
+			<value>false</value>
+			<description>If the bucketing/sorting properties of the table exactly
+				match the grouping key, whether to
+				perform the group by in the mapper
+				by using BucketizedHiveInputFormat. The
+				only downside to this
+				is that
+				it limits the number of mappers to the number of files.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.map.groupby.sorted.testmode</name>
+			<value>false</value>
+			<description>If the bucketing/sorting properties of the table exactly
+				match the grouping key, whether to
+				perform the group by in the mapper
+				by using BucketizedHiveInputFormat. If
+				the test mode is set, the plan
+				is not converted, but a query property is set to denote the same.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.new.job.grouping.set.cardinality</name>
+			<value>30</value>
+			<description>
+				Whether a new map-reduce job should be launched for
+				grouping
+				sets/rollups/cubes.
+				For a query like: select a, b, c,
+				count(1) from T group by a, b, c with
+				rollup;
+				4 rows are created per
+				row: (a, b, c), (a, b, null), (a, null, null),
+				(null, null, null).
+				This can lead to explosion across map-reduce boundary if the
+				cardinality
+				of T is very high,
+				and map-side aggregation does not do a
+				very good job.
+
+				This parameter decides if hive should add an
+				additional map-reduce job.
+				If the grouping set
+				cardinality (4 in the
+				example above), is more than this value, a new MR job is
+				added under
+				the
+				assumption that the orginal group by will reduce the data size.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.join.emit.interval</name>
+			<value>1000</value>
+			<description>How many rows in the right-most join operand Hive should
+				buffer before emitting the join result.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.join.cache.size</name>
+			<value>25000</value>
+			<description>How many rows in the joining tables (except the
+				streaming table) should be cached in memory.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.mapjoin.bucket.cache.size</name>
+			<value>100</value>
+			<description>How many values in each keys in the map-joined table
+				should be cached in memory.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.mapjoin.cache.numrows</name>
+			<value>25000</value>
+			<description>How many rows should be cached by jdbm for map join.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.optimize.skewjoin</name>
+			<value>false</value>
+			<description>Whether to enable skew join optimization.
+				The algorithm
+				is as follows: At runtime, detect the keys with a large
+				skew. Instead
+				of
+				processing those keys, store them temporarily in a hdfs directory.
+				In a
+				follow-up map-reduce
+				job, process those skewed keys. The same key
+				need not be skewed for all
+				the tables, and so,
+				the follow-up
+				map-reduce job (for the skewed keys) would be much
+				faster, since it
+				would be a
+				map-join.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.skewjoin.key</name>
+			<value>100000</value>
+			<description>Determine if we get a skew key in join. If we see more
+				than the specified number of rows with the same key in join
+				operator,
+				we think the key as a skew join key.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.skewjoin.mapjoin.map.tasks</name>
+			<value>10000</value>
+			<description> Determine the number of map task used in the follow up
+				map join job
+				for a skew join. It should be used together with
+				hive.skewjoin.mapjoin.min.split
+				to perform a fine grained control.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.skewjoin.mapjoin.min.split</name>
+			<value>33554432</value>
+			<description> Determine the number of map task at most used in the
+				follow up map join job
+				for a skew join by specifying the minimum
+				split size. It should be used
+				together with
+				hive.skewjoin.mapjoin.map.tasks to perform a fine grained control.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.mapred.mode</name>
+			<value>nonstrict</value>
+			<description>The mode in which the hive operations are being
+				performed.
+				In strict mode, some risky queries are not allowed to run.
+				They
+				include:
+				Cartesian Product.
+				No partition being picked up for a
+				query.
+				Comparing bigints and strings.
+				Comparing bigints and doubles.
+				Orderby without limit.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.enforce.bucketmapjoin</name>
+			<value>false</value>
+			<description>If the user asked for bucketed map-side join, and it
+				cannot be performed,
+				should the query fail or not ? For eg, if the
+				buckets in the tables being
+				joined are
+				not a multiple of each other,
+				bucketed map-side join cannot be
+				performed, and the
+				query will fail if
+				hive.enforce.bucketmapjoin is set to true.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.script.maxerrsize</name>
+			<value>100000</value>
+			<description>Maximum number of bytes a script is allowed to emit to
+				standard error (per map-reduce task). This prevents runaway scripts
+				from filling logs partitions to capacity
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.script.allow.partial.consumption</name>
+			<value>false</value>
+			<description> When enabled, this option allows a user script to exit
+				successfully without consuming all the data from the standard input.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.script.operator.id.env.var</name>
+			<value>HIVE_SCRIPT_OPERATOR_ID</value>
+			<description> Name of the environment variable that holds the unique
+				script operator ID in the user's transform function (the custom
+				mapper/reducer that the user has specified in the query)
+			</description>
+		</property>
+
+		<property>
+			<name>hive.script.operator.truncate.env</name>
+			<value>false</value>
+			<description>Truncate each environment variable for external script
+				in scripts operator to 20KB (to fit system limits)
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.compress.output</name>
+			<value>false</value>
+			<description> This controls whether the final outputs of a query (to
+				a local/hdfs file or a hive table) is compressed. The compression
+				codec and other options are determined from hadoop config variables
+				mapred.output.compress*
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.compress.intermediate</name>
+			<value>false</value>
+			<description> This controls whether intermediate files produced by
+				hive between multiple map-reduce jobs are compressed. The
+				compression codec and other options are determined from hadoop
+				config variables mapred.output.compress*
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.parallel</name>
+			<value>false</value>
+			<description>Whether to execute jobs in parallel</description>
+		</property>
+
+		<property>
+			<name>hive.exec.parallel.thread.number</name>
+			<value>8</value>
+			<description>How many jobs at most can be executed in parallel
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.rowoffset</name>
+			<value>false</value>
+			<description>Whether to provide the row offset virtual column
+			</description>
+		</property>
+
+		<property>
+			<name>hive.task.progress</name>
+			<value>false</value>
+			<description>Whether Hive should periodically update task progress
+				counters during execution. Enabling this allows task progress to be
+				monitored more closely in the job tracker, but may impose a
+				performance penalty. This flag is automatically set to true for jobs
+				with hive.exec.dynamic.partition set to true.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.hwi.war.file</name>
+			<value>lib/hive-hwi-@VERSION@.war</value>
+			<description>This sets the path to the HWI war file, relative to
+				${HIVE_HOME}.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.hwi.listen.host</name>
+			<value>0.0.0.0</value>
+			<description>This is the host address the Hive Web Interface will
+				listen on
+			</description>
+		</property>
+
+		<property>
+			<name>hive.hwi.listen.port</name>
+			<value>9999</value>
+			<description>This is the port the Hive Web Interface will listen on
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.pre.hooks</name>
+			<value></value>
+			<description>Comma-separated list of pre-execution hooks to be
+				invoked for each statement. A pre-execution hook is specified as the
+				name of a Java class which implements the
+				org.apache.hadoop.hive.ql.hooks.ExecuteWithHookContext interface.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.post.hooks</name>
+			<value></value>
+			<description>Comma-separated list of post-execution hooks to be
+				invoked for each statement. A post-execution hook is specified as
+				the name of a Java class which implements the
+				org.apache.hadoop.hive.ql.hooks.ExecuteWithHookContext interface.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.failure.hooks</name>
+			<value></value>
+			<description>Comma-separated list of on-failure hooks to be invoked
+				for each statement. An on-failure hook is specified as the name of
+				Java class which implements the
+				org.apache.hadoop.hive.ql.hooks.ExecuteWithHookContext interface.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.init.hooks</name>
+			<value></value>
+			<description>A comma separated list of hooks to be invoked at the
+				beginning of HMSHandler initialization. Aninit hook is specified as
+				the name of Java class which extends
+				org.apache.hadoop.hive.metastore.MetaStoreInitListener.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.client.stats.publishers</name>
+			<value></value>
+			<description>Comma-separated list of statistics publishers to be
+				invoked on counters on each job. A client stats publisher is
+				specified as the name of a Java class which implements the
+				org.apache.hadoop.hive.ql.stats.ClientStatsPublisher interface.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.client.stats.counters</name>
+			<value></value>
+			<description>Subset of counters that should be of interest for
+				hive.client.stats.publishers (when one wants to limit their
+				publishing). Non-display names should be used
+			</description>
+		</property>
+
+		<property>
+			<name>hive.merge.mapfiles</name>
+			<value>true</value>
+			<description>Merge small files at the end of a map-only job
+			</description>
+		</property>
+
+		<property>
+			<name>hive.merge.mapredfiles</name>
+			<value>false</value>
+			<description>Merge small files at the end of a map-reduce job
+			</description>
+		</property>
+
+		<property>
+			<name>hive.heartbeat.interval</name>
+			<value>1000</value>
+			<description>Send a heartbeat after this interval - used by mapjoin
+				and filter operators
+			</description>
+		</property>
+
+		<property>
+			<name>hive.merge.size.per.task</name>
+			<value>256000000</value>
+			<description>Size of merged files at the end of the job</description>
+		</property>
+
+		<property>
+			<name>hive.merge.smallfiles.avgsize</name>
+			<value>16000000</value>
+			<description>When the average output file size of a job is less than
+				this number, Hive will start an additional map-reduce job to merge
+				the output files into bigger files. This is only done for map-only
+				jobs if hive.merge.mapfiles is true, and for map-reduce jobs if
+				hive.merge.mapredfiles is true.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.mapjoin.smalltable.filesize</name>
+			<value>25000000</value>
+			<description>The threshold for the input file size of the small
+				tables; if the file size is smaller than this threshold, it will try
+				to convert the common join into map join
+			</description>
+		</property>
+
+		<property>
+			<name>hive.ignore.mapjoin.hint</name>
+			<value>true</value>
+			<description>Ignore the mapjoin hint</description>
+		</property>
+
+		<property>
+			<name>hive.mapjoin.localtask.max.memory.usage</name>
+			<value>0.90</value>
+			<description>This number means how much memory the local task can
+				take to hold the key/value into in-memory hash table; If the local
+				task's memory usage is more than this number, the local task will be
+				abort by themself. It means the data of small table is too large to
+				be hold in the memory.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.mapjoin.followby.gby.localtask.max.memory.usage</name>
+			<value>0.55</value>
+			<description>This number means how much memory the local task can
+				take to hold the key/value into in-memory hash table when this map
+				join followed by a group by; If the local task's memory usage is
+				more than this number, the local task will be abort by themself. It
+				means the data of small table is too large to be hold in the memory.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.mapjoin.check.memory.rows</name>
+			<value>100000</value>
+			<description>The number means after how many rows processed it needs
+				to check the memory usage
+			</description>
+		</property>
+
+		<property>
+			<name>hive.auto.convert.join</name>
+			<value>false</value>
+			<description>Whether Hive enable the optimization about converting
+				common join into mapjoin based on the input file size
+			</description>
+		</property>
+
+		<property>
+			<name>hive.auto.convert.join.noconditionaltask</name>
+			<value>true</value>
+			<description>Whether Hive enable the optimization about converting
+				common join into mapjoin based on the input file
+				size. If this
+				paramater is on, and the sum of size for n-1 of the
+				tables/partitions for a n-way join is smaller than the
+				specified
+				size, the join is directly converted to a mapjoin (there is no
+				conditional task).
+			</description>
+		</property>
+
+		<property>
+			<name>hive.auto.convert.join.noconditionaltask.size</name>
+			<value>10000000</value>
+			<description>If hive.auto.convert.join.noconditionaltask is off, this
+				parameter does not take affect. However, if it
+				is on, and the sum of
+				size for n-1 of the tables/partitions for a
+				n-way join is smaller
+				than this size, the join is directly
+				converted to a mapjoin(there is
+				no conditional task). The default is 10MB
+			</description>
+		</property>
+
+		<property>
+			<name>hive.optimize.mapjoin.mapreduce</name>
+			<value>false</value>
+			<description>If hive.auto.convert.join is off, this parameter does
+				not take
+				affect. If it is on, and if there are map-join jobs followed
+				by a
+				map-reduce
+				job (for e.g a group by), each map-only job is merged
+				with the
+				following
+				map-reduce job.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.script.auto.progress</name>
+			<value>false</value>
+			<description>Whether Hive Tranform/Map/Reduce Clause should
+				automatically send progress information to TaskTracker to avoid the
+				task getting killed because of inactivity. Hive sends progress
+				information when the script is outputting to stderr. This option
+				removes the need of periodically producing stderr messages, but
+				users should be cautious because this may prevent infinite loops in
+				the scripts to be killed by TaskTracker.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.script.serde</name>
+			<value>org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe</value>
+			<description>The default serde for trasmitting input data to and
+				reading output data from the user scripts.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.binary.record.max.length</name>
+			<value>1000</value>
+			<description>Read from a binary stream and treat each
+				hive.binary.record.max.length bytes as a record.
+				The last record
+				before the end of stream can have less than
+				hive.binary.record.max.length bytes
+			</description>
+		</property>
+
+
+		<property>
+			<name>hive.script.recordreader</name>
+			<value>org.apache.hadoop.hive.ql.exec.TextRecordReader</value>
+			<description>The default record reader for reading data from the user
+				scripts.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.script.recordwriter</name>
+			<value>org.apache.hadoop.hive.ql.exec.TextRecordWriter</value>
+			<description>The default record writer for writing data to the user
+				scripts.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.input.format</name>
+			<value>org.apache.hadoop.hive.ql.io.CombineHiveInputFormat</value>
+			<description>The default input format. Set this to HiveInputFormat if
+				you encounter problems with CombineHiveInputFormat.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.udtf.auto.progress</name>
+			<value>false</value>
+			<description>Whether Hive should automatically send progress
+				information to TaskTracker when using UDTF's to prevent the task
+				getting killed because of inactivity. Users should be cautious
+				because this may prevent TaskTracker from killing tasks with infinte
+				loops.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.mapred.reduce.tasks.speculative.execution</name>
+			<value>true</value>
+			<description>Whether speculative execution for reducers should be
+				turned on.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.counters.pull.interval</name>
+			<value>1000</value>
+			<description>The interval with which to poll the JobTracker for the
+				counters the running job. The smaller it is the more load there will
+				be on the jobtracker, the higher it is the less granular the caught
+				will be.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.querylog.location</name>
+			<value>/tmp/${user.name}</value>
+			<description>
+				Location of Hive run time structured log file
+			</description>
+		</property>
+
+		<property>
+			<name>hive.querylog.enable.plan.progress</name>
+			<value>true</value>
+			<description>
+				Whether to log the plan's progress every time a job's
+				progress is checked.
+				These logs are written to the location specified
+				by
+				hive.querylog.location
+			</description>
+		</property>
+
+		<property>
+			<name>hive.querylog.plan.progress.interval</name>
+			<value>60000</value>
+			<description>
+				The interval to wait between logging the plan's progress
+				in
+				milliseconds.
+				If there is a whole number percentage change in the
+				progress of the
+				mappers or the reducers,
+				the progress is logged
+				regardless of this value.
+				The actual interval will be the ceiling of
+				(this value divided by the
+				value of
+				hive.exec.counters.pull.interval)
+				multiplied by the value of hive.exec.counters.pull.interval
+				I.e. if
+				it is not divide evenly by the value of
+				hive.exec.counters.pull.interval it will be
+				logged less frequently
+				than specified.
+				This only has an effect if
+				hive.querylog.enable.plan.progress is set to
+				true.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.enforce.bucketing</name>
+			<value>false</value>
+			<description>Whether bucketing is enforced. If true, while inserting
+				into the table, bucketing is enforced.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.enforce.sorting</name>
+			<value>false</value>
+			<description>Whether sorting is enforced. If true, while inserting
+				into the table, sorting is enforced.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.optimize.bucketingsorting</name>
+			<value>true</value>
+			<description>If hive.enforce.bucketing or hive.enforce.sorting is
+				true, dont create a reducer for enforcing
+				bucketing/sorting for
+				queries of the form:
+				insert overwrite table T2 select * from T1;
+				where T1 and T2 are bucketed/sorted by the same keys into the same
+				number
+				of buckets.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.enforce.sortmergebucketmapjoin</name>
+			<value>false</value>
+			<description>If the user asked for sort-merge bucketed map-side join,
+				and it cannot be performed,
+				should the query fail or not ?
+			</description>
+		</property>
+
+		<property>
+			<name>hive.auto.convert.sortmerge.join</name>
+			<value>false</value>
+			<description>Will the join be automatically converted to a sort-merge
+				join, if the joined tables pass
+				the criteria for sort-merge join.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.auto.convert.sortmerge.join.bigtable.selection.policy
+			</name>
+			<value>org.apache.hadoop.hive.ql.optimizer.AvgPartitionSizeBasedBigTableSelectorForAutoSMJ
+			</value>
+			<description>The policy to choose the big table for automatic
+				conversion to sort-merge join.
+				By default, the table with the largest
+				partitions is assigned the big
+				table. All policies are:
+				. based on
+				position of the table - the leftmost table is selected
+				org.apache.hadoop.hive.ql.optimizer.LeftmostBigTableSMJ.
+				. based on
+				total size (all the partitions selected in the query) of
+				the table
+				org.apache.hadoop.hive.ql.optimizer.TableSizeBasedBigTableSelectorForAutoSMJ.
+				. based on average size (all the partitions selected in the query)
+				of the table
+				org.apache.hadoop.hive.ql.optimizer.AvgPartitionSizeBasedBigTableSelectorForAutoSMJ.
+				New policies can be added in future.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.ds.connection.url.hook</name>
+			<value></value>
+			<description>Name of the hook to use for retriving the JDO connection
+				URL. If empty, the value in javax.jdo.option.ConnectionURL is used
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.ds.retry.attempts</name>
+			<value>1</value>
+			<description>The number of times to retry a metastore call if there
+				were a connection error
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.ds.retry.interval</name>
+			<value>1000</value>
+			<description>The number of miliseconds between metastore retry
+				attempts
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.server.min.threads</name>
+			<value>200</value>
+			<description>Minimum number of worker threads in the Thrift server's
+				pool.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.server.max.threads</name>
+			<value>100000</value>
+			<description>Maximum number of worker threads in the Thrift server's
+				pool.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.server.tcp.keepalive</name>
+			<value>true</value>
+			<description>Whether to enable TCP keepalive for the metastore
+				server. Keepalive will prevent accumulation of half-open
+				connections.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.sasl.enabled</name>
+			<value>false</value>
+			<description>If true, the metastore thrift interface will be secured
+				with SASL. Clients must authenticate with Kerberos.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.thrift.framed.transport.enabled</name>
+			<value>false</value>
+			<description>If true, the metastore thrift interface will use
+				TFramedTransport. When false (default) a standard TTransport is
+				used.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.kerberos.keytab.file</name>
+			<value></value>
+			<description>The path to the Kerberos Keytab file containing the
+				metastore thrift server's service principal.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.kerberos.principal</name>
+			<value>hive-metastore/_HOST@EXAMPLE.COM</value>
+			<description>The service principal for the metastore thrift server.
+				The special string _HOST will be replaced automatically with the
+				correct host name.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.cluster.delegation.token.store.class</name>
+			<value>org.apache.hadoop.hive.thrift.MemoryTokenStore</value>
+			<description>The delegation token store implementation. Set to
+				org.apache.hadoop.hive.thrift.ZooKeeperTokenStore for load-balanced
+				cluster.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.cluster.delegation.token.store.zookeeper.connectString
+			</name>
+			<value>localhost:2181</value>
+			<description>The ZooKeeper token store connect string.</description>
+		</property>
+
+		<property>
+			<name>hive.cluster.delegation.token.store.zookeeper.znode</name>
+			<value>/hive/cluster/delegation</value>
+			<description>The root path for token store data.</description>
+		</property>
+
+		<property>
+			<name>hive.cluster.delegation.token.store.zookeeper.acl</name>
+			<value>sasl:hive/host1@EXAMPLE.COM:cdrwa,sasl:hive/host2@EXAMPLE.COM:cdrwa
+			</value>
+			<description>ACL for token store entries. List comma separated all
+				server principals for the cluster.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.cache.pinobjtypes</name>
+			<value>Table,StorageDescriptor,SerDeInfo,Partition,Database,Type,FieldSchema,Order
+			</value>
+			<description>List of comma separated metastore object types that
+				should be pinned in the cache
+			</description>
+		</property>
+
+		<property>
+			<name>hive.optimize.reducededuplication</name>
+			<value>true</value>
+			<description>Remove extra map-reduce jobs if the data is already
+				clustered by the same key which needs to be used again. This should
+				always be set to true. Since it is a new feature, it has been made
+				configurable.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.optimize.reducededuplication.min.reducer</name>
+			<value>4</value>
+			<description>Reduce deduplication merges two RSs by moving
+				key/parts/reducer-num of the child RS to parent RS.
+				That means if
+				reducer-num of the child RS is fixed (order by or forced
+				bucketing)
+				and small, it can make very slow, single MR.
+				The optimization will be
+				disabled if number of reducers is less than
+				specified value.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.dynamic.partition</name>
+			<value>true</value>
+			<description>Whether or not to allow dynamic partitions in DML/DDL.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.dynamic.partition.mode</name>
+			<value>strict</value>
+			<description>In strict mode, the user must specify at least one
+				static partition in case the user accidentally overwrites all
+				partitions.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.max.dynamic.partitions</name>
+			<value>1000</value>
+			<description>Maximum number of dynamic partitions allowed to be
+				created in total.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.max.dynamic.partitions.pernode</name>
+			<value>100</value>
+			<description>Maximum number of dynamic partitions allowed to be
+				created in each mapper/reducer node.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.max.created.files</name>
+			<value>100000</value>
+			<description>Maximum number of HDFS files created by all
+				mappers/reducers in a MapReduce job.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.default.partition.name</name>
+			<value>__HIVE_DEFAULT_PARTITION__</value>
+			<description>The default partition name in case the dynamic partition
+				column value is null/empty string or anyother values that cannot be
+				escaped. This value must not contain any special character used in
+				HDFS URI (e.g., ':', '%', '/' etc). The user has to be aware that
+				the dynamic partition value should not contain this value to avoid
+				confusions.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.stats.dbclass</name>
+			<value>jdbc:derby</value>
+			<description>The default database that stores temporary hive
+				statistics.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.stats.autogather</name>
+			<value>true</value>
+			<description>A flag to gather statistics automatically during the
+				INSERT OVERWRITE command.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.stats.jdbcdriver</name>
+			<value>org.apache.derby.jdbc.EmbeddedDriver</value>
+			<description>The JDBC driver for the database that stores temporary
+				hive statistics.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.stats.dbconnectionstring</name>
+			<value>jdbc:derby:;databaseName=TempStatsStore;create=true</value>
+			<description>The default connection string for the database that
+				stores temporary hive statistics.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.stats.default.publisher</name>
+			<value></value>
+			<description>The Java class (implementing the StatsPublisher
+				interface) that is used by default if hive.stats.dbclass is not JDBC
+				or HBase.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.stats.default.aggregator</name>
+			<value></value>
+			<description>The Java class (implementing the StatsAggregator
+				interface) that is used by default if hive.stats.dbclass is not JDBC
+				or HBase.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.stats.jdbc.timeout</name>
+			<value>30</value>
+			<description>Timeout value (number of seconds) used by JDBC
+				connection and statements.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.stats.retries.max</name>
+			<value>0</value>
+			<description>Maximum number of retries when stats
+				publisher/aggregator got an exception updating intermediate
+				database. Default is no tries on failures.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.stats.retries.wait</name>
+			<value>3000</value>
+			<description>The base waiting window (in milliseconds) before the
+				next retry. The actual wait time is calculated by baseWindow *
+				failues baseWindow * (failure 1) * (random number between
+				[0.0,1.0]).
+			</description>
+		</property>
+
+		<property>
+			<name>hive.stats.reliable</name>
+			<value>false</value>
+			<description>Whether queries will fail because stats cannot be
+				collected completely accurately.
+				If this is set to true,
+				reading/writing from/into a partition may fail
+				becuase the stats
+				could not be computed accurately.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.stats.collect.tablekeys</name>
+			<value>false</value>
+			<description>Whether join and group by keys on tables are derived and
+				maintained in the QueryPlan.
+				This is useful to identify how tables
+				are accessed and to determine if
+				they should be bucketed.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.stats.collect.scancols</name>
+			<value>false</value>
+			<description>Whether column accesses are tracked in the QueryPlan.
+				This is useful to identify how tables are accessed and to determine
+				if there are wasted columns that can be trimmed.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.stats.ndv.error</name>
+			<value>20.0</value>
+			<description>Standard error expressed in percentage. Provides a
+				tradeoff between accuracy and compute cost.A lower value for error
+				indicates higher accuracy and a higher compute cost.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.stats.key.prefix.max.length</name>
+			<value>200</value>
+			<description>
+				Determines if when the prefix of the key used for
+				intermediate stats
+				collection
+				exceeds a certain length, a hash of the
+				key is used instead. If the value
+				&lt; 0 then hashing
+				is never used,
+				if the value >= 0 then hashing is used only when the
+				key prefixes
+				length
+				exceeds that value. The key prefix is defined as everything
+				preceding the
+				task ID in the key.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.support.concurrency</name>
+			<value>false</value>
+			<description>Whether hive supports concurrency or not. A zookeeper
+				instance must be up and running for the default hive lock manager to
+				support read-write locks.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.lock.numretries</name>
+			<value>100</value>
+			<description>The number of times you want to try to get all the locks
+			</description>
+		</property>
+
+		<property>
+			<name>hive.unlock.numretries</name>
+			<value>10</value>
+			<description>The number of times you want to retry to do one unlock
+			</description>
+		</property>
+
+		<property>
+			<name>hive.lock.sleep.between.retries</name>
+			<value>60</value>
+			<description>The sleep time (in seconds) between various retries
+			</description>
+		</property>
+
+		<property>
+			<name>hive.zookeeper.quorum</name>
+			<value></value>
+			<description>The list of zookeeper servers to talk to. This is only
+				needed for read/write locks.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.zookeeper.client.port</name>
+			<value>2181</value>
+			<description>The port of zookeeper servers to talk to. This is only
+				needed for read/write locks.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.zookeeper.session.timeout</name>
+			<value>600000</value>
+			<description>Zookeeper client's session timeout. The client is
+				disconnected, and as a result, all locks released, if a heartbeat is
+				not sent in the timeout.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.zookeeper.namespace</name>
+			<value>hive_zookeeper_namespace</value>
+			<description>The parent node under which all zookeeper nodes are
+				created.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.zookeeper.clean.extra.nodes</name>
+			<value>false</value>
+			<description>Clean extra nodes at the end of the session.
+			</description>
+		</property>
+
+		<property>
+			<name>fs.har.impl</name>
+			<value>org.apache.hadoop.hive.shims.HiveHarFileSystem</value>
+			<description>The implementation for accessing Hadoop Archives. Note
+				that this won't be applicable to Hadoop vers less than 0.20
+			</description>
+		</property>
+
+		<property>
+			<name>hive.archive.enabled</name>
+			<value>false</value>
+			<description>Whether archiving operations are permitted</description>
+		</property>
+
+		<property>
+			<name>hive.fetch.output.serde</name>
+			<value>org.apache.hadoop.hive.serde2.DelimitedJSONSerDe</value>
+			<description>The serde used by FetchTask to serialize the fetch
+				output.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.mode.local.auto</name>
+			<value>false</value>
+			<description> Let hive determine whether to run in local mode
+				automatically
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.drop.ignorenonexistent</name>
+			<value>true</value>
+			<description>
+				Do not report an error if DROP TABLE/VIEW specifies a
+				non-existent
+				table/view
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.show.job.failure.debug.info</name>
+			<value>true</value>
+			<description>
+				If a job fails, whether to provide a link in the CLI to
+				the task with
+				the
+				most failures, along with debugging hints if
+				applicable.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.auto.progress.timeout</name>
+			<value>0</value>
+			<description>
+				How long to run autoprogressor for the script/UDTF
+				operators (in
+				seconds).
+				Set to 0 for forever.
+			</description>
+		</property>
+
+		<!-- HBase Storage Handler Parameters -->
+
+		<property>
+			<name>hive.hbase.wal.enabled</name>
+			<value>true</value>
+			<description>Whether writes to HBase should be forced to the
+				write-ahead log. Disabling this improves HBase write performance at
+				the risk of lost writes in case of a crash.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.table.parameters.default</name>
+			<value></value>
+			<description>Default property values for newly created tables
+			</description>
+		</property>
+
+		<property>
+			<name>hive.entity.separator</name>
+			<value>@</value>
+			<description>Separator used to construct names of tables and
+				partitions. For example, dbname@tablename@partitionname
+			</description>
+		</property>
+
+		<property>
+			<name>hive.ddl.createtablelike.properties.whitelist</name>
+			<value></value>
+			<description>Table Properties to copy over when executing a Create
+				Table Like.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.variable.substitute</name>
+			<value>true</value>
+			<description>This enables substitution using syntax like ${var}
+				${system:var} and ${env:var}.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.variable.substitute.depth</name>
+			<value>40</value>
+			<description>The maximum replacements the substitution engine will
+				do.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.conf.validation</name>
+			<value>true</value>
+			<description>Eables type checking for registered hive configurations
+			</description>
+		</property>
+
+		<property>
+			<name>hive.security.authorization.enabled</name>
+			<value>false</value>
+			<description>enable or disable the hive client authorization
+			</description>
+		</property>
+
+		<property>
+			<name>hive.security.authorization.createtable.user.grants</name>
+			<value></value>
+			<description>the privileges automatically granted to some users
+				whenever a table gets created.
+				An example like
+				"userX,userY:select;userZ:create" will grant select
+				privilege to
+				userX and userY,
+				and grant create privilege to userZ whenever a new
+				table created.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.security.authorization.createtable.group.grants</name>
+			<value></value>
+			<description>the privileges automatically granted to some groups
+				whenever a table gets created.
+				An example like
+				"groupX,groupY:select;groupZ:create" will grant select
+				privilege to
+				groupX and groupY,
+				and grant create privilege to groupZ whenever a
+				new table created.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.security.authorization.createtable.role.grants</name>
+			<value></value>
+			<description>the privileges automatically granted to some roles
+				whenever a table gets created.
+				An example like
+				"roleX,roleY:select;roleZ:create" will grant select
+				privilege to
+				roleX and roleY,
+				and grant create privilege to roleZ whenever a new
+				table created.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.security.authorization.createtable.owner.grants</name>
+			<value></value>
+			<description>the privileges automatically granted to the owner
+				whenever a table gets created.
+				An example like "select,drop" will
+				grant select and drop privilege to
+				the owner of the table
+			</description>
+		</property>
+
+		<property>
+			<name>hive.metastore.authorization.storage.checks</name>
+			<value>false</value>
+			<description>Should the metastore do authorization checks against the
+				underlying storage
+				for operations like drop-partition (disallow the
+				drop-partition if the
+				user in
+				question doesn't have permissions to
+				delete the corresponding directory
+				on the storage).
+			</description>
+		</property>
+
+		<property>
+			<name>hive.error.on.empty.partition</name>
+			<value>false</value>
+			<description>Whether to throw an excpetion if dynamic partition
+				insert generates empty results.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.index.compact.file.ignore.hdfs</name>
+			<value>false</value>
+			<description>True the hdfs location stored in the index file will be
+				igbored at runtime.
+				If the data got moved or the name of the cluster
+				got changed, the
+				index data should still be usable.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.optimize.index.filter.compact.minsize</name>
+			<value>5368709120</value>
+			<description>Minimum size (in bytes) of the inputs on which a compact
+				index is automatically used.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.optimize.index.filter.compact.maxsize</name>
+			<value>-1</value>
+			<description>Maximum size (in bytes) of the inputs on which a compact
+				index is automatically used.
+				A negative number is equivalent to
+				infinity.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.index.compact.query.max.size</name>
+			<value>10737418240</value>
+			<description>The maximum number of bytes that a query using the
+				compact index can read. Negative value is equivalent to infinity.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.index.compact.query.max.entries</name>
+			<value>10000000</value>
+			<description>The maximum number of index entries to read during a
+				query that uses the compact index. Negative value is equivalent to
+				infinity.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.index.compact.binary.search</name>
+			<value>true</value>
+			<description>Whether or not to use a binary search to find the
+				entries in an index table that match the filter, where possible
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exim.uri.scheme.whitelist</name>
+			<value>hdfs,pfile</value>
+			<description>A comma separated list of acceptable URI schemes for
+				import and export.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.lock.mapred.only.operation</name>
+			<value>false</value>
+			<description>This param is to control whether or not only do lock on
+				queries
+				that need to execute at least one mapred job.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.limit.row.max.size</name>
+			<value>100000</value>
+			<description>When trying a smaller subset of data for simple LIMIT,
+				how much size we need to guarantee
+				each row to have at least.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.limit.optimize.limit.file</name>
+			<value>10</value>
+			<description>When trying a smaller subset of data for simple LIMIT,
+				maximum number of files we can
+				sample.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.limit.optimize.enable</name>
+			<value>false</value>
+			<description>Whether to enable to optimization to trying a smaller
+				subset of data for simple LIMIT first.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.limit.optimize.fetch.max</name>
+			<value>50000</value>
+			<description>Maximum number of rows allowed for a smaller subset of
+				data for simple LIMIT, if it is a fetch query.
+				Insert queries are not
+				restricted by this limit.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.rework.mapredwork</name>
+			<value>false</value>
+			<description>should rework the mapred work or not.
+				This is first
+				introduced by SymlinkTextInputFormat to replace symlink
+				files with
+				real paths at compile time.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.concatenate.check.index</name>
+			<value>true</value>
+			<description>If this sets to true, hive will throw error when doing
+				'alter table tbl_name [partSpec] concatenate' on a table/partition
+				that has indexes on it. The reason the user want to set this to true
+				is because it can help user to avoid handling all index drop,
+				recreation,
+				rebuild work. This is very helpful for tables with
+				thousands of partitions.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.sample.seednumber</name>
+			<value>0</value>
+			<description>A number used to percentage sampling. By changing this
+				number, user will change the subsets
+				of data sampled.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.io.exception.handlers</name>
+			<value></value>
+			<description>A list of io exception handler class names. This is used
+				to construct a list exception handlers to handle exceptions thrown
+				by record readers
+			</description>
+		</property>
+
+		<property>
+			<name>hive.autogen.columnalias.prefix.label</name>
+			<value>_c</value>
+			<description>String used as a prefix when auto generating column
+				alias.
+				By default the prefix label will be appended with a column
+				position
+				number to form the column alias. Auto generation would
+				happen if an
+				aggregate function is used in a select clause without an
+				explicit
+				alias.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.autogen.columnalias.prefix.includefuncname</name>
+			<value>false</value>
+			<description>Whether to include function name in the column alias
+				auto generated by hive.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.perf.logger</name>
+			<value>org.apache.hadoop.hive.ql.log.PerfLogger</value>
+			<description>The class responsible logging client side performance
+				metrics. Must be a subclass of
+				org.apache.hadoop.hive.ql.log.PerfLogger
+			</description>
+		</property>
+
+		<property>
+			<name>hive.start.cleanup.scratchdir</name>
+			<value>false</value>
+			<description>To cleanup the hive scratchdir while starting the hive
+				server
+			</description>
+		</property>
+
+		<property>
+			<name>hive.output.file.extension</name>
+			<value></value>
+			<description>String used as a file extension for output files. If not
+				set, defaults to the codec extension for text files (e.g. ".gz"), or
+				no extension otherwise.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.insert.into.multilevel.dirs</name>
+			<value>false</value>
+			<description>Where to insert into multilevel directories like
+				"insert
+				directory '/HIVEFT25686/chinna/' from table"
+			</description>
+		</property>
+
+		<property>
+			<name>hive.warehouse.subdir.inherit.perms</name>
+			<value>false</value>
+			<description>Set this to true if the the table directories should
+				inherit the
+				permission of the warehouse or database directory instead
+				of being created
+				with the permissions derived from dfs umask
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.job.debug.capture.stacktraces</name>
+			<value>true</value>
+			<description>Whether or not stack traces parsed from the task logs of
+				a sampled failed task for
+				each failed job should be stored in the
+				SessionState
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.driver.run.hooks</name>
+			<value></value>
+			<description>A comma separated list of hooks which implement
+				HiveDriverRunHook and will be run at the
+				beginning and end of
+				Driver.run, these will be run in the order specified
+			</description>
+		</property>
+
+		<property>
+			<name>hive.ddl.output.format</name>
+			<value>text</value>
+			<description>
+				The data format to use for DDL output. One of "text"
+				(for human
+				readable text) or "json" (for a json object).
+			</description>
+		</property>
+
+		<property>
+			<name>hive.transform.escape.input</name>
+			<value>false</value>
+			<description>
+				This adds an option to escape special chars (newlines,
+				carriage returns
+				and
+				tabs) when they are passed to the user script.
+				This is useful if the hive
+				tables
+				can contain data that contains
+				special characters.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.rcfile.use.explicit.header</name>
+			<value>true</value>
+			<description>
+				If this is set the header for RC Files will simply be
+				RCF. If this is
+				not
+				set the header will be that borrowed from sequence
+				files, e.g. SEQ-
+				followed
+				by the input and output RC File formats.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.multi.insert.move.tasks.share.dependencies</name>
+			<value>false</value>
+			<description>
+				If this is set all move tasks for tables/partitions (not
+				directories)
+				at the end of a
+				multi-insert query will only begin once
+				the dependencies for all these move
+				tasks have been
+				met.
+				Advantages: If
+				concurrency is enabled, the locks will only be released once the
+				query has
+				finished, so with this config enabled, the time when the
+				table/partition is
+				generated will be much closer to when the lock on
+				it is released.
+				Disadvantages: If concurrency is not enabled, with
+				this disabled,
+				the tables/partitions which
+				are produced by this query
+				and finish earlier will be available for
+				querying
+				much earlier. Since
+				the locks are only released once the query finishes,
+				this
+				does not
+				apply if concurrency is enabled.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.fetch.task.conversion</name>
+			<value>minimal</value>
+			<description>
+				Some select queries can be converted to single FETCH
+				task minimizing
+				latency.
+				Currently the query should be single sourced
+				not having any subquery and
+				should not have
+				any aggregations or
+				distincts (which incurrs RS), lateral views and
+				joins.
+				1. minimal :
+				SELECT STAR, FILTER on partition columns, LIMIT only
+				2. more :
+				SELECT, FILTER, LIMIT only (TABLESAMPLE, virtual columns)
+			</description>
+		</property>
+
+		<property>
+			<name>hive.hmshandler.retry.attempts</name>
+			<value>1</value>
+			<description>The number of times to retry a HMSHandler call if there
+				were a connection error
+			</description>
+		</property>
+
+		<property>
+			<name>hive.hmshandler.retry.interval</name>
+			<value>1000</value>
+			<description>The number of miliseconds between HMSHandler retry
+				attempts
+			</description>
+		</property>
+
+		<property>
+			<name>hive.server.read.socket.timeout</name>
+			<value>10</value>
+			<description>Timeout for the HiveServer to close the connection if no
+				response from the client in N seconds, defaults to 10 seconds.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.server.tcp.keepalive</name>
+			<value>true</value>
+			<description>Whether to enable TCP keepalive for the Hive server.
+				Keepalive will prevent accumulation of half-open connections.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.decode.partition.name</name>
+			<value>false</value>
+			<description>Whether to show the unquoted partition names in query
+				results.
+			</description>
+		</property>
+
+		<property>
+			<name>hive.log4j.file</name>
+			<value></value>
+			<description>Hive log4j configuration file.
+				If the property is not
+				set, then logging will be initialized using
+				hive-log4j.properties
+				found on the classpath.
+				If the property is set, the value must be a
+				valid URI (java.net.URI,
+				e.g. "file:///tmp/my-logging.properties"),
+				which you can then
+				extract a URL from and pass to
+				PropertyConfigurator.configure(URL).
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.log4j.file</name>
+			<value></value>
+			<description>Hive log4j configuration file for execution mode(sub
+				command).
+				If the property is not set, then logging will be
+				initialized using
+				hive-exec-log4j.properties found on the classpath.
+				If the property is set, the value must be a valid URI (java.net.URI,
+				e.g. "file:///tmp/my-logging.properties"), which you can then
+				extract a URL from and pass to PropertyConfigurator.configure(URL).
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.infer.bucket.sort</name>
+			<value>false</value>
+			<description>
+				If this is set, when writing partitions, the metadata
+				will include the
+				bucketing/sorting
+				properties with which the data was
+				written if any (this will not overwrite the
+				metadata
+				inherited from
+				the table if the table is bucketed/sorted)
+			</description>
+		</property>
+
+		<property>
+			<name>hive.exec.infer.bucket.sort.num.buckets.power.two</name>
+			<value>false</value>
+			<description>
+				If this is set, when setting the number of reducers for
+				the map reduce
+				task which writes the
+				final output files, it will
+				choose a number which is a power of two,
+				unless the user specifies
+				the number of reducers to use using mapred.reduce.tasks. The number
+				of
+				reducers
+				may be set to a power of two, only to be followed by a
+				merge task
+				meaning preventing
+				anything from being inferred.
+				With
+				hive.exec.infer.bucket.sort set to true:
+				Advantages: If this is not
+				set, the number of buckets for partitions will seem
+				arbitrary,
+				which
+				means that the number of mappers used for optimized joins, for
+				example, will
+				be very low. With this set, since the number of buckets
+				used for any
+				partition is
+				a power of two, the number of mappers used
+				for optimized joins will
+				be the least
+				number of buckets used by any
+				partition being joined.
+				Disadvantages: This may mean a much larger or
+				much smaller number of reducers
+				being used in the
+				final map reduce
+				job, e.g. if a job was originally going to take 257
+				reducers,
+				it will
+				now take 512 reducers, similarly if the max number of reducers
+				is
+				511,
+				and a job was going to use this many, it will now use 256
+				reducers.
+
+			</description>
+		</property>
+
+		<property>
+			<name>hive.groupby.orderby.position.alias</name>
+			<value>false</value>
+			<description>Whether to enable using Column Position Alias in Group
+				By or Order By
+			</description>
+		</property>
+
+		<property>
+			<name>hive.server2.thrift.min.worker.threads</name>
+			<value>5</value>
+			<description>Minimum number of Thrift worker threads</description>
+		</property>
+
+		<property>
+			<name>hive.server2.thrift.max.worker.threads</name>
+			<value>100</value>
+			<description>Maximum number of Thrift worker threads</description>
+		</property>
+
+		<property>
+			<name>hive.server2.thrift.port</name>
+			<value>10000</value>
+			<description>Port number of HiveServer2 Thrift interface.
+				Can be
+				overridden by setting $HIVE_SERVER2_THRIFT_PORT
+			</description>
+		</property>
+
+		<property>
+			<name>hive.server2.thrift.bind.host</name>
+			<value>localhost</value>
+			<description>Bind host on which to run the HiveServer2 Thrift
+				interface.
+				Can be overridden by setting
+				$HIVE_SERVER2_THRIFT_BIND_HOST
+			</description>
+		</property>
+
+		<property>
+			<name>hive.server2.authentication</name>
+			<value>NONE</value>
+			<description>
+				Client authentication types.
+				NONE: no authentication
+				check
+				LDAP: LDAP/AD based authentication
+				KERBEROS: Kerberos/GSSAPI
+				authentication
+				CUSTOM: Custom authentication provider
+				(Use with
+				property hive.server2.custom.authentication.class)
+			</description>
+		</property>
+
+		<property>
+			<name>hive.server2.custom.authentication.class</name>
+			<value></value>
+			<description>
+				Custom authentication class. Used when property
+				'hive.server2.authentication' is set to 'CUSTOM'. Provided class
+				must be a proper implementation of the interface
+				org.apache.hive.service.auth.PasswdAuthenticationProvider.
+				HiveServer2
+				will call its Authenticate(user, passed) method to
+				authenticate
+				requests.
+				The implementation may optionally extend the
+				Hadoop's
+				org.apache.hadoop.conf.Configured class to grab Hive's
+				Configuration
+				object.
+			</description>
+		</property>
+
+		<property>
+			<name>>hive.server2.authentication.kerberos.principal</name>
+			<value></value>
+			<description>
+				Kerberos server principal
+			</description>
+		</property>
+
+		<property>
+			<name>>hive.server2.authentication.kerberos.keytab</name>
+			<value></value>
+			<description>
+				Kerberos keytab file for server principal
+			</description>
+		</property>
+
+		<property>
+			<name>hive.server2.authentication.ldap.url</name>
+			<value></value>
+			<description>
+				LDAP connection URL
+			</description>
+		</property>
+
+		<property>
+			<name>hive.server2.authentication.ldap.baseDN</name>
+			<value></value>
+			<description>
+				LDAP base DN
+			</description>
+		</property>
+
+		<property>
+			<name>hive.server2.enable.doAs</name>
+			<value>true</value>
+			<description>
+				Setting this property to true will have hive server2
+				execute
+				hive operations as the user making the calls to it.
+			</description>
+		</property>
+
+
+	</configuration>
+
+	<!-- Hive Execution Parameters -->
+	<property>
+		<name>mapred.reduce.tasks</name>
+		<value>-1</value>
+		<description>The default number of reduce tasks per job. Typically set
+			to a prime close to the number of available hosts. Ignored when
+			mapred.job.tracker is "local". Hadoop set this to 1 by default,
+			whereas hive uses -1 as its default value.
+			By setting this property to
+			-1, Hive will automatically figure out what
+			should be the number of
+			reducers.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.reducers.bytes.per.reducer</name>
+		<value>1000000000</value>
+		<description>size per reducer.The default is 1G, i.e if the input size
+			is 10G, it will use 10 reducers.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.reducers.max</name>
+		<value>999</value>
+		<description>max number of reducers will be used. If the one
+			specified
+			in the configuration parameter mapred.reduce.tasks is
+			negative, hive
+			will use this one as the max number of reducers when
+			automatically
+			determine number of reducers.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.cli.print.header</name>
+		<value>false</value>
+		<description>Whether to print the names of the columns in query
+			output.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.cli.print.current.db</name>
+		<value>false</value>
+		<description>Whether to include the current database in the hive
+			prompt.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.cli.prompt</name>
+		<value>hive</value>
+		<description>Command line prompt configuration value. Other hiveconf
+			can be used in
+			this configuration value. Variable substitution will
+			only be invoked at
+			the hive
+			cli startup.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.cli.pretty.output.num.cols</name>
+		<value>-1</value>
+		<description>The number of columns to use when formatting output
+			generated
+			by the DESCRIBE PRETTY table_name command. If the value of
+			this
+			property
+			is -1, then hive will use the auto-detected terminal
+			width.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.scratchdir</name>
+		<value>/tmp/hive-${user.name}</value>
+		<description>Scratch space for Hive jobs</description>
+	</property>
+
+	<property>
+		<name>hive.exec.local.scratchdir</name>
+		<value>/tmp/${user.name}</value>
+		<description>Local scratch space for Hive jobs</description>
+	</property>
+
+	<property>
+		<name>hive.test.mode</name>
+		<value>false</value>
+		<description>whether hive is running in test mode. If yes, it turns on
+			sampling and prefixes the output tablename
+		</description>
+	</property>
+
+	<property>
+		<name>hive.test.mode.prefix</name>
+		<value>test_</value>
+		<description>if hive is running in test mode, prefixes the output
+			table by this string
+		</description>
+	</property>
+
+	<!-- If the input table is not bucketed, the denominator of the tablesample 
+		is determinied by the parameter below -->
+	<!-- For example, the following query: -->
+	<!-- INSERT OVERWRITE TABLE dest -->
+	<!-- SELECT col1 from src -->
+	<!-- would be converted to -->
+	<!-- INSERT OVERWRITE TABLE test_dest -->
+	<!-- SELECT col1 from src TABLESAMPLE (BUCKET 1 out of 32 on rand(1)) -->
+	<property>
+		<name>hive.test.mode.samplefreq</name>
+		<value>32</value>
+		<description>if hive is running in test mode and table is not
+			bucketed, sampling frequency
+		</description>
+	</property>
+
+	<property>
+		<name>hive.test.mode.nosamplelist</name>
+		<value></value>
+		<description>if hive is running in test mode, dont sample the above
+			comma seperated list of tables
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.uris</name>
+		<value></value>
+		<description>Thrift uri for the remote metastore. Used by metastore
+			client to connect to remote metastore.
+		</description>
+	</property>
+
+	<property>
+		<name>javax.jdo.option.ConnectionURL</name>
+		<value>jdbc:derby:;databaseName=metastore_db;create=true</value>
+		<description>JDBC connect string for a JDBC metastore</description>
+	</property>
+
+	<property>
+		<name>javax.jdo.option.ConnectionDriverName</name>
+		<value>org.apache.derby.jdbc.EmbeddedDriver</value>
+		<description>Driver class name for a JDBC metastore</description>
+	</property>
+
+	<property>
+		<name>javax.jdo.PersistenceManagerFactoryClass</name>
+		<value>org.datanucleus.jdo.JDOPersistenceManagerFactory</value>
+		<description>class implementing the jdo persistence</description>
+	</property>
+
+	<property>
+		<name>javax.jdo.option.DetachAllOnCommit</name>
+		<value>true</value>
+		<description>detaches all objects from session so that they can be
+			used after transaction is committed
+		</description>
+	</property>
+
+	<property>
+		<name>javax.jdo.option.NonTransactionalRead</name>
+		<value>true</value>
+		<description>reads outside of transactions</description>
+	</property>
+
+	<property>
+		<name>javax.jdo.option.ConnectionUserName</name>
+		<value>APP</value>
+		<description>username to use against metastore database</description>
+	</property>
+
+	<property>
+		<name>javax.jdo.option.ConnectionPassword</name>
+		<value>mine</value>
+		<description>password to use against metastore database</description>
+	</property>
+
+	<property>
+		<name>javax.jdo.option.Multithreaded</name>
+		<value>true</value>
+		<description>Set this to true if multiple threads access metastore
+			through JDO concurrently.
+		</description>
+	</property>
+
+	<property>
+		<name>datanucleus.connectionPoolingType</name>
+		<value>DBCP</value>
+		<description>Uses a DBCP connection pool for JDBC metastore
+		</description>
+	</property>
+
+	<property>
+		<name>datanucleus.validateTables</name>
+		<value>false</value>
+		<description>validates existing schema against code. turn this on if
+			you want to verify existing schema
+		</description>
+	</property>
+
+	<property>
+		<name>datanucleus.validateColumns</name>
+		<value>false</value>
+		<description>validates existing schema against code. turn this on if
+			you want to verify existing schema
+		</description>
+	</property>
+
+	<property>
+		<name>datanucleus.validateConstraints</name>
+		<value>false</value>
+		<description>validates existing schema against code. turn this on if
+			you want to verify existing schema
+		</description>
+	</property>
+
+	<property>
+		<name>datanucleus.storeManagerType</name>
+		<value>rdbms</value>
+		<description>metadata store type</description>
+	</property>
+
+	<property>
+		<name>datanucleus.autoCreateSchema</name>
+		<value>true</value>
+		<description>creates necessary schema on a startup if one doesn't
+			exist. set this to false, after creating it once
+		</description>
+	</property>
+
+	<property>
+		<name>datanucleus.autoStartMechanismMode</name>
+		<value>checked</value>
+		<description>throw exception if metadata tables are incorrect
+		</description>
+	</property>
+
+	<property>
+		<name>datanucleus.transactionIsolation</name>
+		<value>read-committed</value>
+		<description>Default transaction isolation level for identity
+			generation.
+		</description>
+	</property>
+
+	<property>
+		<name>datanucleus.cache.level2</name>
+		<value>false</value>
+		<description>Use a level 2 cache. Turn this off if metadata is changed
+			independently of hive metastore server
+		</description>
+	</property>
+
+	<property>
+		<name>datanucleus.cache.level2.type</name>
+		<value>SOFT</value>
+		<description>SOFT=soft reference based cache, WEAK=weak reference
+			based cache.
+		</description>
+	</property>
+
+	<property>
+		<name>datanucleus.identifierFactory</name>
+		<value>datanucleus</value>
+		<description>Name of the identifier factory to use when generating
+			table/column names etc. 'datanucleus' is used for backward
+			compatibility
+		</description>
+	</property>
+
+	<property>
+		<name>datanucleus.plugin.pluginRegistryBundleCheck</name>
+		<value>LOG</value>
+		<description>Defines what happens when plugin bundles are found and
+			are duplicated [EXCEPTION|LOG|NONE]
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.warehouse.dir</name>
+		<value>/user/hive/warehouse</value>
+		<description>location of default database for the warehouse
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.execute.setugi</name>
+		<value>false</value>
+		<description>In unsecure mode, setting this property to true will
+			cause the metastore to execute DFS operations using the client's
+			reported user and group permissions. Note that this property must be
+			set on both the client and server sides. Further note that its best
+			effort. If client sets its to true and server sets it to false,
+			client setting will be ignored.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.event.listeners</name>
+		<value></value>
+		<description>list of comma seperated listeners for metastore events.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.partition.inherit.table.properties</name>
+		<value></value>
+		<description>list of comma seperated keys occurring in table
+			properties which will get inherited to newly created partitions. *
+			implies all the keys will get inherited.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metadata.export.location</name>
+		<value></value>
+		<description>When used in conjunction with the
+			org.apache.hadoop.hive.ql.parse.MetaDataExportListener pre event
+			listener, it is the location to which the metadata will be exported.
+			The default is an empty string, which results in the metadata being
+			exported to the current user's home directory on HDFS.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metadata.move.exported.metadata.to.trash</name>
+		<value></value>
+		<description>When used in conjunction with the
+			org.apache.hadoop.hive.ql.parse.MetaDataExportListener pre event
+			listener, this setting determines if the metadata that is exported
+			will subsequently be moved to the user's trash directory alongside
+			the dropped table data. This ensures that the metadata will be
+			cleaned up along with the dropped table data.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.partition.name.whitelist.pattern</name>
+		<value></value>
+		<description>Partition names will be checked against this regex
+			pattern and rejected if not matched.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.end.function.listeners</name>
+		<value></value>
+		<description>list of comma separated listeners for the end of
+			metastore functions.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.event.expiry.duration</name>
+		<value>0</value>
+		<description>Duration after which events expire from events table (in
+			seconds)
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.event.clean.freq</name>
+		<value>0</value>
+		<description>Frequency at which timer task runs to purge expired
+			events in metastore(in seconds).
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.connect.retries</name>
+		<value>5</value>
+		<description>Number of retries while opening a connection to metastore
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.failure.retries</name>
+		<value>3</value>
+		<description>Number of retries upon failure of Thrift metastore calls
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.client.connect.retry.delay</name>
+		<value>1</value>
+		<description>Number of seconds for the client to wait between
+			consecutive connection attempts
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.client.socket.timeout</name>
+		<value>20</value>
+		<description>MetaStore Client socket timeout in seconds</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.rawstore.impl</name>
+		<value>org.apache.hadoop.hive.metastore.ObjectStore</value>
+		<description>Name of the class that implements
+			org.apache.hadoop.hive.metastore.rawstore interface. This class is
+			used to store and retrieval of raw metadata objects such as table,
+			database
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.batch.retrieve.max</name>
+		<value>300</value>
+		<description>Maximum number of objects (tables/partitions) can be
+			retrieved from metastore in one batch. The higher the number, the
+			less the number of round trips is needed to the Hive metastore
+			server, but it may also cause higher memory requirement at the client
+			side.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.batch.retrieve.table.partition.max</name>
+		<value>1000</value>
+		<description>Maximum number of table partitions that metastore
+			internally retrieves in one batch.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.default.fileformat</name>
+		<value>TextFile</value>
+		<description>Default file format for CREATE TABLE statement. Options
+			are TextFile and SequenceFile. Users can explicitly say CREATE TABLE
+			... STORED AS &lt;TEXTFILE|SEQUENCEFILE&gt; to override</description>
+	</property>
+
+	<property>
+		<name>hive.fileformat.check</name>
+		<value>true</value>
+		<description>Whether to check file format or not when loading data
+			files
+		</description>
+	</property>
+
+	<property>
+		<name>hive.map.aggr</name>
+		<value>true</value>
+		<description>Whether to use map-side aggregation in Hive Group By
+			queries
+		</description>
+	</property>
+
+	<property>
+		<name>hive.groupby.skewindata</name>
+		<value>false</value>
+		<description>Whether there is skew in data to optimize group by
+			queries
+		</description>
+	</property>
+
+	<property>
+		<name>hive.optimize.multigroupby.common.distincts</name>
+		<value>true</value>
+		<description>Whether to optimize a multi-groupby query with the same
+			distinct.
+			Consider a query like:
+
+			from src
+			insert overwrite table dest1
+			select col1, count(distinct colx) group by
+			col1
+			insert overwrite table
+			dest2 select col2, count(distinct colx) group by
+			col2;
+
+			With this
+			parameter set to true, first we spray by the distinct value
+			(colx),
+			and then
+			perform the 2 groups bys. This makes sense if map-side
+			aggregation is turned
+			off. However,
+			with maps-side aggregation, it
+			might be useful in some cases to treat the
+			2 inserts independently,
+			thereby performing the query above in 2MR jobs instead of 3 (due to
+			spraying
+			by distinct key first).
+			If this parameter is turned off, we
+			dont consider the fact that the
+			distinct key is the same across
+			different MR jobs.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.groupby.mapaggr.checkinterval</name>
+		<value>100000</value>
+		<description>Number of rows after which size of the grouping
+			keys/aggregation classes is performed
+		</description>
+	</property>
+
+	<property>
+		<name>hive.mapred.local.mem</name>
+		<value>0</value>
+		<description>For local mode, memory of the mappers/reducers
+		</description>
+	</property>
+
+	<property>
+		<name>hive.mapjoin.followby.map.aggr.hash.percentmemory</name>
+		<value>0.3</value>
+		<description>Portion of total memory to be used by map-side grup
+			aggregation hash table, when this group by is followed by map join
+		</description>
+	</property>
+
+	<property>
+		<name>hive.map.aggr.hash.force.flush.memory.threshold</name>
+		<value>0.9</value>
+		<description>The max memory to be used by map-side grup aggregation
+			hash table, if the memory usage is higher than this number, force to
+			flush data
+		</description>
+	</property>
+
+	<property>
+		<name>hive.map.aggr.hash.percentmemory</name>
+		<value>0.5</value>
+		<description>Portion of total memory to be used by map-side grup
+			aggregation hash table
+		</description>
+	</property>
+
+	<property>
+		<name>hive.map.aggr.hash.min.reduction</name>
+		<value>0.5</value>
+		<description>Hash aggregation will be turned off if the ratio between
+			hash
+			table size and input rows is bigger than this number. Set to 1 to
+			make
+			sure
+			hash aggregation is never turned off.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.optimize.cp</name>
+		<value>true</value>
+		<description>Whether to enable column pruner</description>
+	</property>
+
+	<property>
+		<name>hive.optimize.index.filter</name>
+		<value>false</value>
+		<description>Whether to enable automatic use of indexes</description>
+	</property>
+
+	<property>
+		<name>hive.optimize.index.groupby</name>
+		<value>false</value>
+		<description>Whether to enable optimization of group-by queries using
+			Aggregate indexes.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.optimize.ppd</name>
+		<value>true</value>
+		<description>Whether to enable predicate pushdown</description>
+	</property>
+
+	<property>
+		<name>hive.optimize.ppd.storage</name>
+		<value>true</value>
+		<description>Whether to push predicates down into storage handlers.
+			Ignored when hive.optimize.ppd is false.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.ppd.recognizetransivity</name>
+		<value>true</value>
+		<description>Whether to transitively replicate predicate filters over
+			equijoin conditions.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.optimize.groupby</name>
+		<value>true</value>
+		<description>Whether to enable the bucketed group by from bucketed
+			partitions/tables.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.optimize.skewjoin.compiletime</name>
+		<value>false</value>
+		<description>Whether to create a separate plan for skewed keys for the
+			tables in the join.
+			This is based on the skewed keys stored in the
+			metadata. At compile time,
+			the plan is broken
+			into different joins: one
+			for the skewed keys, and the other for the
+			remaining keys. And then,
+			a
+			union is performed for the 2 joins generated above. So unless the
+			same skewed key is present
+			in both the joined tables, the join for the
+			skewed key will be
+			performed as a map-side join.
+
+			The main difference
+			between this paramater and hive.optimize.skewjoin is
+			that this
+			parameter
+			uses the skew information stored in the metastore to
+			optimize the plan at
+			compile time itself.
+			If there is no skew
+			information in the metadata, this parameter will
+			not have any affect.
+			Both hive.optimize.skewjoin.compiletime and hive.optimize.skewjoin
+			should
+			be set to true.
+			Ideally, hive.optimize.skewjoin should be
+			renamed as
+			hive.optimize.skewjoin.runtime, but not doing
+			so for
+			backward compatibility.
+
+			If the skew information is correctly stored in
+			the metadata,
+			hive.optimize.skewjoin.compiletime
+			would change the query
+			plan to take care of it, and hive.optimize.skewjoin
+			will be a no-op.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.optimize.union.remove</name>
+		<value>false</value>
+		<description>
+			Whether to remove the union and push the operators
+			between union and the
+			filesink above
+			union. This avoids an extra scan
+			of the output by union. This is
+			independently useful for union
+			queries, and specially useful when hive.optimize.skewjoin.compiletime
+			is set
+			to true, since an
+			extra union is inserted.
+
+			The merge is triggered
+			if either of hive.merge.mapfiles or
+			hive.merge.mapredfiles is set to
+			true.
+			If the user has set hive.merge.mapfiles to true and
+			hive.merge.mapredfiles to false, the idea was the
+			number of reducers
+			are few, so the number of files anyway are small.
+			However, with this
+			optimization,
+			we are increasing the number of files possibly by a big
+			margin. So, we
+			merge aggresively.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.mapred.supports.subdirectories</name>
+		<value>false</value>
+		<description>Whether the version of hadoop which is running supports
+			sub-directories for tables/partitions.
+			Many hive optimizations can be
+			applied if the hadoop version supports
+			sub-directories for
+			tables/partitions. It was added by MAPREDUCE-1501
+		</description>
+	</property>
+
+	<property>
+		<name>hive.multigroupby.singlemr</name>
+		<value>false</value>
+		<description>Whether to optimize multi group by query to generate
+			single M/R
+			job plan. If the multi group by query has common group by
+			keys, it will
+			be
+			optimized to generate single M/R job.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.map.groupby.sorted</name>
+		<value>false</value>
+		<description>If the bucketing/sorting properties of the table exactly
+			match the grouping key, whether to
+			perform the group by in the mapper
+			by using BucketizedHiveInputFormat. The
+			only downside to this
+			is that
+			it limits the number of mappers to the number of files.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.map.groupby.sorted.testmode</name>
+		<value>false</value>
+		<description>If the bucketing/sorting properties of the table exactly
+			match the grouping key, whether to
+			perform the group by in the mapper
+			by using BucketizedHiveInputFormat. If
+			the test mode is set, the plan
+			is not converted, but a query property is set to denote the same.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.new.job.grouping.set.cardinality</name>
+		<value>30</value>
+		<description>
+			Whether a new map-reduce job should be launched for
+			grouping
+			sets/rollups/cubes.
+			For a query like: select a, b, c, count(1)
+			from T group by a, b, c with
+			rollup;
+			4 rows are created per row: (a, b,
+			c), (a, b, null), (a, null, null),
+			(null, null, null).
+			This can lead to
+			explosion across map-reduce boundary if the cardinality
+			of T is very
+			high,
+			and map-side aggregation does not do a very good job.
+
+			This
+			parameter decides if hive should add an additional map-reduce job.
+			If
+			the grouping set
+			cardinality (4 in the example above), is more than
+			this value, a new MR job is
+			added under the
+			assumption that the orginal
+			group by will reduce the data size.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.join.emit.interval</name>
+		<value>1000</value>
+		<description>How many rows in the right-most join operand Hive should
+			buffer before emitting the join result.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.join.cache.size</name>
+		<value>25000</value>
+		<description>How many rows in the joining tables (except the streaming
+			table) should be cached in memory.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.mapjoin.bucket.cache.size</name>
+		<value>100</value>
+		<description>How many values in each keys in the map-joined table
+			should be cached in memory.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.mapjoin.cache.numrows</name>
+		<value>25000</value>
+		<description>How many rows should be cached by jdbm for map join.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.optimize.skewjoin</name>
+		<value>false</value>
+		<description>Whether to enable skew join optimization.
+			The algorithm is
+			as follows: At runtime, detect the keys with a large
+			skew. Instead of
+			processing those keys, store them temporarily in a hdfs directory. In
+			a
+			follow-up map-reduce
+			job, process those skewed keys. The same key
+			need not be skewed for all
+			the tables, and so,
+			the follow-up map-reduce
+			job (for the skewed keys) would be much faster,
+			since it would be a
+			map-join.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.skewjoin.key</name>
+		<value>100000</value>
+		<description>Determine if we get a skew key in join. If we see more
+			than the specified number of rows with the same key in join operator,
+			we think the key as a skew join key.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.skewjoin.mapjoin.map.tasks</name>
+		<value>10000</value>
+		<description> Determine the number of map task used in the follow up
+			map join job
+			for a skew join. It should be used together with
+			hive.skewjoin.mapjoin.min.split
+			to perform a fine grained control.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.skewjoin.mapjoin.min.split</name>
+		<value>33554432</value>
+		<description> Determine the number of map task at most used in the
+			follow up map join job
+			for a skew join by specifying the minimum split
+			size. It should be used
+			together with
+			hive.skewjoin.mapjoin.map.tasks
+			to perform a fine grained control.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.mapred.mode</name>
+		<value>nonstrict</value>
+		<description>The mode in which the hive operations are being
+			performed.
+			In strict mode, some risky queries are not allowed to run.
+			They
+			include:
+			Cartesian Product.
+			No partition being picked up for a
+			query.
+			Comparing bigints and strings.
+			Comparing bigints and doubles.
+			Orderby without limit.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.enforce.bucketmapjoin</name>
+		<value>false</value>
+		<description>If the user asked for bucketed map-side join, and it
+			cannot be performed,
+			should the query fail or not ? For eg, if the
+			buckets in the tables being
+			joined are
+			not a multiple of each other,
+			bucketed map-side join cannot be
+			performed, and the
+			query will fail if
+			hive.enforce.bucketmapjoin is set to true.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.script.maxerrsize</name>
+		<value>100000</value>
+		<description>Maximum number of bytes a script is allowed to emit to
+			standard error (per map-reduce task). This prevents runaway scripts
+			from filling logs partitions to capacity
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.script.allow.partial.consumption</name>
+		<value>false</value>
+		<description> When enabled, this option allows a user script to exit
+			successfully without consuming all the data from the standard input.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.script.operator.id.env.var</name>
+		<value>HIVE_SCRIPT_OPERATOR_ID</value>
+		<description> Name of the environment variable that holds the unique
+			script operator ID in the user's transform function (the custom
+			mapper/reducer that the user has specified in the query)
+		</description>
+	</property>
+
+	<property>
+		<name>hive.script.operator.truncate.env</name>
+		<value>false</value>
+		<description>Truncate each environment variable for external script in
+			scripts operator to 20KB (to fit system limits)
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.compress.output</name>
+		<value>false</value>
+		<description> This controls whether the final outputs of a query (to a
+			local/hdfs file or a hive table) is compressed. The compression codec
+			and other options are determined from hadoop config variables
+			mapred.output.compress*
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.compress.intermediate</name>
+		<value>false</value>
+		<description> This controls whether intermediate files produced by
+			hive between multiple map-reduce jobs are compressed. The compression
+			codec and other options are determined from hadoop config variables
+			mapred.output.compress*
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.parallel</name>
+		<value>false</value>
+		<description>Whether to execute jobs in parallel</description>
+	</property>
+
+	<property>
+		<name>hive.exec.parallel.thread.number</name>
+		<value>8</value>
+		<description>How many jobs at most can be executed in parallel
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.rowoffset</name>
+		<value>false</value>
+		<description>Whether to provide the row offset virtual column
+		</description>
+	</property>
+
+	<property>
+		<name>hive.task.progress</name>
+		<value>false</value>
+		<description>Whether Hive should periodically update task progress
+			counters during execution. Enabling this allows task progress to be
+			monitored more closely in the job tracker, but may impose a
+			performance penalty. This flag is automatically set to true for jobs
+			with hive.exec.dynamic.partition set to true.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.hwi.war.file</name>
+		<value>lib/hive-hwi-@VERSION@.war</value>
+		<description>This sets the path to the HWI war file, relative to
+			${HIVE_HOME}.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.hwi.listen.host</name>
+		<value>0.0.0.0</value>
+		<description>This is the host address the Hive Web Interface will
+			listen on
+		</description>
+	</property>
+
+	<property>
+		<name>hive.hwi.listen.port</name>
+		<value>9999</value>
+		<description>This is the port the Hive Web Interface will listen on
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.pre.hooks</name>
+		<value></value>
+		<description>Comma-separated list of pre-execution hooks to be invoked
+			for each statement. A pre-execution hook is specified as the name of
+			a Java class which implements the
+			org.apache.hadoop.hive.ql.hooks.ExecuteWithHookContext interface.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.post.hooks</name>
+		<value></value>
+		<description>Comma-separated list of post-execution hooks to be
+			invoked for each statement. A post-execution hook is specified as the
+			name of a Java class which implements the
+			org.apache.hadoop.hive.ql.hooks.ExecuteWithHookContext interface.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.failure.hooks</name>
+		<value></value>
+		<description>Comma-separated list of on-failure hooks to be invoked
+			for each statement. An on-failure hook is specified as the name of
+			Java class which implements the
+			org.apache.hadoop.hive.ql.hooks.ExecuteWithHookContext interface.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.init.hooks</name>
+		<value></value>
+		<description>A comma separated list of hooks to be invoked at the
+			beginning of HMSHandler initialization. Aninit hook is specified as
+			the name of Java class which extends
+			org.apache.hadoop.hive.metastore.MetaStoreInitListener.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.client.stats.publishers</name>
+		<value></value>
+		<description>Comma-separated list of statistics publishers to be
+			invoked on counters on each job. A client stats publisher is
+			specified as the name of a Java class which implements the
+			org.apache.hadoop.hive.ql.stats.ClientStatsPublisher interface.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.client.stats.counters</name>
+		<value></value>
+		<description>Subset of counters that should be of interest for
+			hive.client.stats.publishers (when one wants to limit their
+			publishing). Non-display names should be used
+		</description>
+	</property>
+
+	<property>
+		<name>hive.merge.mapfiles</name>
+		<value>true</value>
+		<description>Merge small files at the end of a map-only job
+		</description>
+	</property>
+
+	<property>
+		<name>hive.merge.mapredfiles</name>
+		<value>false</value>
+		<description>Merge small files at the end of a map-reduce job
+		</description>
+	</property>
+
+	<property>
+		<name>hive.heartbeat.interval</name>
+		<value>1000</value>
+		<description>Send a heartbeat after this interval - used by mapjoin
+			and filter operators
+		</description>
+	</property>
+
+	<property>
+		<name>hive.merge.size.per.task</name>
+		<value>256000000</value>
+		<description>Size of merged files at the end of the job</description>
+	</property>
+
+	<property>
+		<name>hive.merge.smallfiles.avgsize</name>
+		<value>16000000</value>
+		<description>When the average output file size of a job is less than
+			this number, Hive will start an additional map-reduce job to merge
+			the output files into bigger files. This is only done for map-only
+			jobs if hive.merge.mapfiles is true, and for map-reduce jobs if
+			hive.merge.mapredfiles is true.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.mapjoin.smalltable.filesize</name>
+		<value>25000000</value>
+		<description>The threshold for the input file size of the small
+			tables; if the file size is smaller than this threshold, it will try
+			to convert the common join into map join
+		</description>
+	</property>
+
+	<property>
+		<name>hive.ignore.mapjoin.hint</name>
+		<value>true</value>
+		<description>Ignore the mapjoin hint</description>
+	</property>
+
+	<property>
+		<name>hive.mapjoin.localtask.max.memory.usage</name>
+		<value>0.90</value>
+		<description>This number means how much memory the local task can take
+			to hold the key/value into in-memory hash table; If the local task's
+			memory usage is more than this number, the local task will be abort
+			by themself. It means the data of small table is too large to be hold
+			in the memory.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.mapjoin.followby.gby.localtask.max.memory.usage</name>
+		<value>0.55</value>
+		<description>This number means how much memory the local task can take
+			to hold the key/value into in-memory hash table when this map join
+			followed by a group by; If the local task's memory usage is more than
+			this number, the local task will be abort by themself. It means the
+			data of small table is too large to be hold in the memory.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.mapjoin.check.memory.rows</name>
+		<value>100000</value>
+		<description>The number means after how many rows processed it needs
+			to check the memory usage
+		</description>
+	</property>
+
+	<property>
+		<name>hive.auto.convert.join</name>
+		<value>false</value>
+		<description>Whether Hive enable the optimization about converting
+			common join into mapjoin based on the input file size
+		</description>
+	</property>
+
+	<property>
+		<name>hive.auto.convert.join.noconditionaltask</name>
+		<value>true</value>
+		<description>Whether Hive enable the optimization about converting
+			common join into mapjoin based on the input file
+			size. If this
+			paramater is on, and the sum of size for n-1 of the
+			tables/partitions
+			for a n-way join is smaller than the
+			specified size, the join is
+			directly converted to a mapjoin (there is no
+			conditional task).
+		</description>
+	</property>
+
+	<property>
+		<name>hive.auto.convert.join.noconditionaltask.size</name>
+		<value>10000000</value>
+		<description>If hive.auto.convert.join.noconditionaltask is off, this
+			parameter does not take affect. However, if it
+			is on, and the sum of
+			size for n-1 of the tables/partitions for a n-way
+			join is smaller than
+			this size, the join is directly
+			converted to a mapjoin(there is no
+			conditional task). The default is 10MB
+		</description>
+	</property>
+
+	<property>
+		<name>hive.optimize.mapjoin.mapreduce</name>
+		<value>false</value>
+		<description>If hive.auto.convert.join is off, this parameter does not
+			take
+			affect. If it is on, and if there are map-join jobs followed by a
+			map-reduce
+			job (for e.g a group by), each map-only job is merged with
+			the
+			following
+			map-reduce job.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.script.auto.progress</name>
+		<value>false</value>
+		<description>Whether Hive Tranform/Map/Reduce Clause should
+			automatically send progress information to TaskTracker to avoid the
+			task getting killed because of inactivity. Hive sends progress
+			information when the script is outputting to stderr. This option
+			removes the need of periodically producing stderr messages, but users
+			should be cautious because this may prevent infinite loops in the
+			scripts to be killed by TaskTracker.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.script.serde</name>
+		<value>org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe</value>
+		<description>The default serde for trasmitting input data to and
+			reading output data from the user scripts.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.binary.record.max.length</name>
+		<value>1000</value>
+		<description>Read from a binary stream and treat each
+			hive.binary.record.max.length bytes as a record.
+			The last record
+			before the end of stream can have less than
+			hive.binary.record.max.length bytes
+		</description>
+	</property>
+
+
+	<property>
+		<name>hive.script.recordreader</name>
+		<value>org.apache.hadoop.hive.ql.exec.TextRecordReader</value>
+		<description>The default record reader for reading data from the user
+			scripts.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.script.recordwriter</name>
+		<value>org.apache.hadoop.hive.ql.exec.TextRecordWriter</value>
+		<description>The default record writer for writing data to the user
+			scripts.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.input.format</name>
+		<value>org.apache.hadoop.hive.ql.io.CombineHiveInputFormat</value>
+		<description>The default input format. Set this to HiveInputFormat if
+			you encounter problems with CombineHiveInputFormat.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.udtf.auto.progress</name>
+		<value>false</value>
+		<description>Whether Hive should automatically send progress
+			information to TaskTracker when using UDTF's to prevent the task
+			getting killed because of inactivity. Users should be cautious
+			because this may prevent TaskTracker from killing tasks with infinte
+			loops.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.mapred.reduce.tasks.speculative.execution</name>
+		<value>true</value>
+		<description>Whether speculative execution for reducers should be
+			turned on.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.counters.pull.interval</name>
+		<value>1000</value>
+		<description>The interval with which to poll the JobTracker for the
+			counters the running job. The smaller it is the more load there will
+			be on the jobtracker, the higher it is the less granular the caught
+			will be.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.querylog.location</name>
+		<value>/tmp/${user.name}</value>
+		<description>
+			Location of Hive run time structured log file
+		</description>
+	</property>
+
+	<property>
+		<name>hive.querylog.enable.plan.progress</name>
+		<value>true</value>
+		<description>
+			Whether to log the plan's progress every time a job's
+			progress is checked.
+			These logs are written to the location specified
+			by
+			hive.querylog.location
+		</description>
+	</property>
+
+	<property>
+		<name>hive.querylog.plan.progress.interval</name>
+		<value>60000</value>
+		<description>
+			The interval to wait between logging the plan's progress
+			in
+			milliseconds.
+			If there is a whole number percentage change in the
+			progress of the
+			mappers or the reducers,
+			the progress is logged
+			regardless of this value.
+			The actual interval will be the ceiling of
+			(this value divided by the
+			value of
+			hive.exec.counters.pull.interval)
+			multiplied by the value of hive.exec.counters.pull.interval
+			I.e. if it
+			is not divide evenly by the value of
+			hive.exec.counters.pull.interval
+			it will be
+			logged less frequently than specified.
+			This only has an
+			effect if hive.querylog.enable.plan.progress is set to
+			true.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.enforce.bucketing</name>
+		<value>false</value>
+		<description>Whether bucketing is enforced. If true, while inserting
+			into the table, bucketing is enforced.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.enforce.sorting</name>
+		<value>false</value>
+		<description>Whether sorting is enforced. If true, while inserting
+			into the table, sorting is enforced.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.optimize.bucketingsorting</name>
+		<value>true</value>
+		<description>If hive.enforce.bucketing or hive.enforce.sorting is
+			true, dont create a reducer for enforcing
+			bucketing/sorting for
+			queries of the form:
+			insert overwrite table T2 select * from T1;
+			where
+			T1 and T2 are bucketed/sorted by the same keys into the same number
+			of buckets.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.enforce.sortmergebucketmapjoin</name>
+		<value>false</value>
+		<description>If the user asked for sort-merge bucketed map-side join,
+			and it cannot be performed,
+			should the query fail or not ?
+		</description>
+	</property>
+
+	<property>
+		<name>hive.auto.convert.sortmerge.join</name>
+		<value>false</value>
+		<description>Will the join be automatically converted to a sort-merge
+			join, if the joined tables pass
+			the criteria for sort-merge join.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.auto.convert.sortmerge.join.bigtable.selection.policy
+		</name>
+		<value>org.apache.hadoop.hive.ql.optimizer.AvgPartitionSizeBasedBigTableSelectorForAutoSMJ
+		</value>
+		<description>The policy to choose the big table for automatic
+			conversion to sort-merge join.
+			By default, the table with the largest
+			partitions is assigned the big
+			table. All policies are:
+			. based on
+			position of the table - the leftmost table is selected
+			org.apache.hadoop.hive.ql.optimizer.LeftmostBigTableSMJ.
+			. based on
+			total size (all the partitions selected in the query) of
+			the table
+			org.apache.hadoop.hive.ql.optimizer.TableSizeBasedBigTableSelectorForAutoSMJ.
+			. based on average size (all the partitions selected in the query) of
+			the table
+			org.apache.hadoop.hive.ql.optimizer.AvgPartitionSizeBasedBigTableSelectorForAutoSMJ.
+			New policies can be added in future.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.ds.connection.url.hook</name>
+		<value></value>
+		<description>Name of the hook to use for retriving the JDO connection
+			URL. If empty, the value in javax.jdo.option.ConnectionURL is used
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.ds.retry.attempts</name>
+		<value>1</value>
+		<description>The number of times to retry a metastore call if there
+			were a connection error
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.ds.retry.interval</name>
+		<value>1000</value>
+		<description>The number of miliseconds between metastore retry
+			attempts
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.server.min.threads</name>
+		<value>200</value>
+		<description>Minimum number of worker threads in the Thrift server's
+			pool.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.server.max.threads</name>
+		<value>100000</value>
+		<description>Maximum number of worker threads in the Thrift server's
+			pool.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.server.tcp.keepalive</name>
+		<value>true</value>
+		<description>Whether to enable TCP keepalive for the metastore server.
+			Keepalive will prevent accumulation of half-open connections.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.sasl.enabled</name>
+		<value>false</value>
+		<description>If true, the metastore thrift interface will be secured
+			with SASL. Clients must authenticate with Kerberos.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.thrift.framed.transport.enabled</name>
+		<value>false</value>
+		<description>If true, the metastore thrift interface will use
+			TFramedTransport. When false (default) a standard TTransport is used.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.kerberos.keytab.file</name>
+		<value></value>
+		<description>The path to the Kerberos Keytab file containing the
+			metastore thrift server's service principal.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.kerberos.principal</name>
+		<value>hive-metastore/_HOST@EXAMPLE.COM</value>
+		<description>The service principal for the metastore thrift server.
+			The special string _HOST will be replaced automatically with the
+			correct host name.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.cluster.delegation.token.store.class</name>
+		<value>org.apache.hadoop.hive.thrift.MemoryTokenStore</value>
+		<description>The delegation token store implementation. Set to
+			org.apache.hadoop.hive.thrift.ZooKeeperTokenStore for load-balanced
+			cluster.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.cluster.delegation.token.store.zookeeper.connectString
+		</name>
+		<value>localhost:2181</value>
+		<description>The ZooKeeper token store connect string.</description>
+	</property>
+
+	<property>
+		<name>hive.cluster.delegation.token.store.zookeeper.znode</name>
+		<value>/hive/cluster/delegation</value>
+		<description>The root path for token store data.</description>
+	</property>
+
+	<property>
+		<name>hive.cluster.delegation.token.store.zookeeper.acl</name>
+		<value>sasl:hive/host1@EXAMPLE.COM:cdrwa,sasl:hive/host2@EXAMPLE.COM:cdrwa
+		</value>
+		<description>ACL for token store entries. List comma separated all
+			server principals for the cluster.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.cache.pinobjtypes</name>
+		<value>Table,StorageDescriptor,SerDeInfo,Partition,Database,Type,FieldSchema,Order
+		</value>
+		<description>List of comma separated metastore object types that
+			should be pinned in the cache
+		</description>
+	</property>
+
+	<property>
+		<name>hive.optimize.reducededuplication</name>
+		<value>true</value>
+		<description>Remove extra map-reduce jobs if the data is already
+			clustered by the same key which needs to be used again. This should
+			always be set to true. Since it is a new feature, it has been made
+			configurable.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.optimize.reducededuplication.min.reducer</name>
+		<value>4</value>
+		<description>Reduce deduplication merges two RSs by moving
+			key/parts/reducer-num of the child RS to parent RS.
+			That means if
+			reducer-num of the child RS is fixed (order by or forced
+			bucketing)
+			and small, it can make very slow, single MR.
+			The optimization will be
+			disabled if number of reducers is less than
+			specified value.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.dynamic.partition</name>
+		<value>true</value>
+		<description>Whether or not to allow dynamic partitions in DML/DDL.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.dynamic.partition.mode</name>
+		<value>strict</value>
+		<description>In strict mode, the user must specify at least one static
+			partition in case the user accidentally overwrites all partitions.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.max.dynamic.partitions</name>
+		<value>1000</value>
+		<description>Maximum number of dynamic partitions allowed to be
+			created in total.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.max.dynamic.partitions.pernode</name>
+		<value>100</value>
+		<description>Maximum number of dynamic partitions allowed to be
+			created in each mapper/reducer node.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.max.created.files</name>
+		<value>100000</value>
+		<description>Maximum number of HDFS files created by all
+			mappers/reducers in a MapReduce job.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.default.partition.name</name>
+		<value>__HIVE_DEFAULT_PARTITION__</value>
+		<description>The default partition name in case the dynamic partition
+			column value is null/empty string or anyother values that cannot be
+			escaped. This value must not contain any special character used in
+			HDFS URI (e.g., ':', '%', '/' etc). The user has to be aware that the
+			dynamic partition value should not contain this value to avoid
+			confusions.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.stats.dbclass</name>
+		<value>jdbc:derby</value>
+		<description>The default database that stores temporary hive
+			statistics.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.stats.autogather</name>
+		<value>true</value>
+		<description>A flag to gather statistics automatically during the
+			INSERT OVERWRITE command.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.stats.jdbcdriver</name>
+		<value>org.apache.derby.jdbc.EmbeddedDriver</value>
+		<description>The JDBC driver for the database that stores temporary
+			hive statistics.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.stats.dbconnectionstring</name>
+		<value>jdbc:derby:;databaseName=TempStatsStore;create=true</value>
+		<description>The default connection string for the database that
+			stores temporary hive statistics.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.stats.default.publisher</name>
+		<value></value>
+		<description>The Java class (implementing the StatsPublisher
+			interface) that is used by default if hive.stats.dbclass is not JDBC
+			or HBase.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.stats.default.aggregator</name>
+		<value></value>
+		<description>The Java class (implementing the StatsAggregator
+			interface) that is used by default if hive.stats.dbclass is not JDBC
+			or HBase.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.stats.jdbc.timeout</name>
+		<value>30</value>
+		<description>Timeout value (number of seconds) used by JDBC connection
+			and statements.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.stats.retries.max</name>
+		<value>0</value>
+		<description>Maximum number of retries when stats publisher/aggregator
+			got an exception updating intermediate database. Default is no tries
+			on failures.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.stats.retries.wait</name>
+		<value>3000</value>
+		<description>The base waiting window (in milliseconds) before the next
+			retry. The actual wait time is calculated by baseWindow * failues
+			baseWindow * (failure 1) * (random number between [0.0,1.0]).
+		</description>
+	</property>
+
+	<property>
+		<name>hive.stats.reliable</name>
+		<value>false</value>
+		<description>Whether queries will fail because stats cannot be
+			collected completely accurately.
+			If this is set to true,
+			reading/writing from/into a partition may fail
+			becuase the stats
+			could
+			not be computed accurately.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.stats.collect.tablekeys</name>
+		<value>false</value>
+		<description>Whether join and group by keys on tables are derived and
+			maintained in the QueryPlan.
+			This is useful to identify how tables are
+			accessed and to determine if
+			they should be bucketed.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.stats.collect.scancols</name>
+		<value>false</value>
+		<description>Whether column accesses are tracked in the QueryPlan.
+			This is useful to identify how tables are accessed and to determine
+			if there are wasted columns that can be trimmed.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.stats.ndv.error</name>
+		<value>20.0</value>
+		<description>Standard error expressed in percentage. Provides a
+			tradeoff between accuracy and compute cost.A lower value for error
+			indicates higher accuracy and a higher compute cost.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.stats.key.prefix.max.length</name>
+		<value>200</value>
+		<description>
+			Determines if when the prefix of the key used for
+			intermediate stats collection
+			exceeds a certain length, a hash of the
+			key is used instead. If the
+			value &lt; 0 then hashing
+			is never used, if
+			the value >= 0 then hashing is used only when the key
+			prefixes length
+			exceeds that value. The key prefix is defined as everything preceding
+			the
+			task ID in the key.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.support.concurrency</name>
+		<value>false</value>
+		<description>Whether hive supports concurrency or not. A zookeeper
+			instance must be up and running for the default hive lock manager to
+			support read-write locks.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.lock.numretries</name>
+		<value>100</value>
+		<description>The number of times you want to try to get all the locks
+		</description>
+	</property>
+
+	<property>
+		<name>hive.unlock.numretries</name>
+		<value>10</value>
+		<description>The number of times you want to retry to do one unlock
+		</description>
+	</property>
+
+	<property>
+		<name>hive.lock.sleep.between.retries</name>
+		<value>60</value>
+		<description>The sleep time (in seconds) between various retries
+		</description>
+	</property>
+
+	<property>
+		<name>hive.zookeeper.quorum</name>
+		<value></value>
+		<description>The list of zookeeper servers to talk to. This is only
+			needed for read/write locks.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.zookeeper.client.port</name>
+		<value>2181</value>
+		<description>The port of zookeeper servers to talk to. This is only
+			needed for read/write locks.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.zookeeper.session.timeout</name>
+		<value>600000</value>
+		<description>Zookeeper client's session timeout. The client is
+			disconnected, and as a result, all locks released, if a heartbeat is
+			not sent in the timeout.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.zookeeper.namespace</name>
+		<value>hive_zookeeper_namespace</value>
+		<description>The parent node under which all zookeeper nodes are
+			created.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.zookeeper.clean.extra.nodes</name>
+		<value>false</value>
+		<description>Clean extra nodes at the end of the session.
+		</description>
+	</property>
+
+	<property>
+		<name>fs.har.impl</name>
+		<value>org.apache.hadoop.hive.shims.HiveHarFileSystem</value>
+		<description>The implementation for accessing Hadoop Archives. Note
+			that this won't be applicable to Hadoop vers less than 0.20
+		</description>
+	</property>
+
+	<property>
+		<name>hive.archive.enabled</name>
+		<value>false</value>
+		<description>Whether archiving operations are permitted</description>
+	</property>
+
+	<property>
+		<name>hive.fetch.output.serde</name>
+		<value>org.apache.hadoop.hive.serde2.DelimitedJSONSerDe</value>
+		<description>The serde used by FetchTask to serialize the fetch
+			output.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.mode.local.auto</name>
+		<value>false</value>
+		<description> Let hive determine whether to run in local mode
+			automatically
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.drop.ignorenonexistent</name>
+		<value>true</value>
+		<description>
+			Do not report an error if DROP TABLE/VIEW specifies a
+			non-existent
+			table/view
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.show.job.failure.debug.info</name>
+		<value>true</value>
+		<description>
+			If a job fails, whether to provide a link in the CLI to
+			the task with
+			the
+			most failures, along with debugging hints if
+			applicable.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.auto.progress.timeout</name>
+		<value>0</value>
+		<description>
+			How long to run autoprogressor for the script/UDTF
+			operators (in
+			seconds).
+			Set to 0 for forever.
+		</description>
+	</property>
+
+	<!-- HBase Storage Handler Parameters -->
+
+	<property>
+		<name>hive.hbase.wal.enabled</name>
+		<value>true</value>
+		<description>Whether writes to HBase should be forced to the
+			write-ahead log. Disabling this improves HBase write performance at
+			the risk of lost writes in case of a crash.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.table.parameters.default</name>
+		<value></value>
+		<description>Default property values for newly created tables
+		</description>
+	</property>
+
+	<property>
+		<name>hive.entity.separator</name>
+		<value>@</value>
+		<description>Separator used to construct names of tables and
+			partitions. For example, dbname@tablename@partitionname
+		</description>
+	</property>
+
+	<property>
+		<name>hive.ddl.createtablelike.properties.whitelist</name>
+		<value></value>
+		<description>Table Properties to copy over when executing a Create
+			Table Like.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.variable.substitute</name>
+		<value>true</value>
+		<description>This enables substitution using syntax like ${var}
+			${system:var} and ${env:var}.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.variable.substitute.depth</name>
+		<value>40</value>
+		<description>The maximum replacements the substitution engine will do.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.conf.validation</name>
+		<value>true</value>
+		<description>Eables type checking for registered hive configurations
+		</description>
+	</property>
+
+	<property>
+		<name>hive.security.authorization.enabled</name>
+		<value>false</value>
+		<description>enable or disable the hive client authorization
+		</description>
+	</property>
+
+	<property>
+		<name>hive.security.authorization.createtable.user.grants</name>
+		<value></value>
+		<description>the privileges automatically granted to some users
+			whenever a table gets created.
+			An example like
+			"userX,userY:select;userZ:create" will grant select
+			privilege to userX
+			and userY,
+			and grant create privilege to userZ whenever a new table
+			created.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.security.authorization.createtable.group.grants</name>
+		<value></value>
+		<description>the privileges automatically granted to some groups
+			whenever a table gets created.
+			An example like
+			"groupX,groupY:select;groupZ:create" will grant select
+			privilege to
+			groupX and groupY,
+			and grant create privilege to groupZ whenever a new
+			table created.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.security.authorization.createtable.role.grants</name>
+		<value></value>
+		<description>the privileges automatically granted to some roles
+			whenever a table gets created.
+			An example like
+			"roleX,roleY:select;roleZ:create" will grant select
+			privilege to roleX
+			and roleY,
+			and grant create privilege to roleZ whenever a new table
+			created.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.security.authorization.createtable.owner.grants</name>
+		<value></value>
+		<description>the privileges automatically granted to the owner
+			whenever a table gets created.
+			An example like "select,drop" will
+			grant select and drop privilege to
+			the owner of the table
+		</description>
+	</property>
+
+	<property>
+		<name>hive.metastore.authorization.storage.checks</name>
+		<value>false</value>
+		<description>Should the metastore do authorization checks against the
+			underlying storage
+			for operations like drop-partition (disallow the
+			drop-partition if the
+			user in
+			question doesn't have permissions to
+			delete the corresponding directory
+			on the storage).
+		</description>
+	</property>
+
+	<property>
+		<name>hive.error.on.empty.partition</name>
+		<value>false</value>
+		<description>Whether to throw an excpetion if dynamic partition insert
+			generates empty results.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.index.compact.file.ignore.hdfs</name>
+		<value>false</value>
+		<description>True the hdfs location stored in the index file will be
+			igbored at runtime.
+			If the data got moved or the name of the cluster
+			got changed, the index
+			data should still be usable.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.optimize.index.filter.compact.minsize</name>
+		<value>5368709120</value>
+		<description>Minimum size (in bytes) of the inputs on which a compact
+			index is automatically used.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.optimize.index.filter.compact.maxsize</name>
+		<value>-1</value>
+		<description>Maximum size (in bytes) of the inputs on which a compact
+			index is automatically used.
+			A negative number is equivalent to
+			infinity.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.index.compact.query.max.size</name>
+		<value>10737418240</value>
+		<description>The maximum number of bytes that a query using the
+			compact index can read. Negative value is equivalent to infinity.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.index.compact.query.max.entries</name>
+		<value>10000000</value>
+		<description>The maximum number of index entries to read during a
+			query that uses the compact index. Negative value is equivalent to
+			infinity.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.index.compact.binary.search</name>
+		<value>true</value>
+		<description>Whether or not to use a binary search to find the entries
+			in an index table that match the filter, where possible
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exim.uri.scheme.whitelist</name>
+		<value>hdfs,pfile</value>
+		<description>A comma separated list of acceptable URI schemes for
+			import and export.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.lock.mapred.only.operation</name>
+		<value>false</value>
+		<description>This param is to control whether or not only do lock on
+			queries
+			that need to execute at least one mapred job.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.limit.row.max.size</name>
+		<value>100000</value>
+		<description>When trying a smaller subset of data for simple LIMIT,
+			how much size we need to guarantee
+			each row to have at least.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.limit.optimize.limit.file</name>
+		<value>10</value>
+		<description>When trying a smaller subset of data for simple LIMIT,
+			maximum number of files we can
+			sample.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.limit.optimize.enable</name>
+		<value>false</value>
+		<description>Whether to enable to optimization to trying a smaller
+			subset of data for simple LIMIT first.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.limit.optimize.fetch.max</name>
+		<value>50000</value>
+		<description>Maximum number of rows allowed for a smaller subset of
+			data for simple LIMIT, if it is a fetch query.
+			Insert queries are not
+			restricted by this limit.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.rework.mapredwork</name>
+		<value>false</value>
+		<description>should rework the mapred work or not.
+			This is first
+			introduced by SymlinkTextInputFormat to replace symlink
+			files with
+			real paths at compile time.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.concatenate.check.index</name>
+		<value>true</value>
+		<description>If this sets to true, hive will throw error when doing
+			'alter table tbl_name [partSpec] concatenate' on a table/partition
+			that has indexes on it. The reason the user want to set this to true
+			is because it can help user to avoid handling all index drop,
+			recreation,
+			rebuild work. This is very helpful for tables with
+			thousands of partitions.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.sample.seednumber</name>
+		<value>0</value>
+		<description>A number used to percentage sampling. By changing this
+			number, user will change the subsets
+			of data sampled.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.io.exception.handlers</name>
+		<value></value>
+		<description>A list of io exception handler class names. This is used
+			to construct a list exception handlers to handle exceptions thrown
+			by
+			record readers
+		</description>
+	</property>
+
+	<property>
+		<name>hive.autogen.columnalias.prefix.label</name>
+		<value>_c</value>
+		<description>String used as a prefix when auto generating column
+			alias.
+			By default the prefix label will be appended with a column
+			position
+			number to form the column alias. Auto generation would happen
+			if an
+			aggregate function is used in a select clause without an
+			explicit
+			alias.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.autogen.columnalias.prefix.includefuncname</name>
+		<value>false</value>
+		<description>Whether to include function name in the column alias auto
+			generated by hive.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.perf.logger</name>
+		<value>org.apache.hadoop.hive.ql.log.PerfLogger</value>
+		<description>The class responsible logging client side performance
+			metrics. Must be a subclass of
+			org.apache.hadoop.hive.ql.log.PerfLogger
+		</description>
+	</property>
+
+	<property>
+		<name>hive.start.cleanup.scratchdir</name>
+		<value>false</value>
+		<description>To cleanup the hive scratchdir while starting the hive
+			server
+		</description>
+	</property>
+
+	<property>
+		<name>hive.output.file.extension</name>
+		<value></value>
+		<description>String used as a file extension for output files. If not
+			set, defaults to the codec extension for text files (e.g. ".gz"), or
+			no extension otherwise.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.insert.into.multilevel.dirs</name>
+		<value>false</value>
+		<description>Where to insert into multilevel directories like
+			"insert
+			directory '/HIVEFT25686/chinna/' from table"
+		</description>
+	</property>
+
+	<property>
+		<name>hive.warehouse.subdir.inherit.perms</name>
+		<value>false</value>
+		<description>Set this to true if the the table directories should
+			inherit the
+			permission of the warehouse or database directory instead
+			of being created
+			with the permissions derived from dfs umask
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.job.debug.capture.stacktraces</name>
+		<value>true</value>
+		<description>Whether or not stack traces parsed from the task logs of
+			a sampled failed task for
+			each failed job should be stored in the
+			SessionState
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.driver.run.hooks</name>
+		<value></value>
+		<description>A comma separated list of hooks which implement
+			HiveDriverRunHook and will be run at the
+			beginning and end of
+			Driver.run, these will be run in the order specified
+		</description>
+	</property>
+
+	<property>
+		<name>hive.ddl.output.format</name>
+		<value>text</value>
+		<description>
+			The data format to use for DDL output. One of "text" (for
+			human
+			readable text) or "json" (for a json object).
+		</description>
+	</property>
+
+	<property>
+		<name>hive.transform.escape.input</name>
+		<value>false</value>
+		<description>
+			This adds an option to escape special chars (newlines,
+			carriage returns
+			and
+			tabs) when they are passed to the user script.
+			This is useful if the hive
+			tables
+			can contain data that contains
+			special characters.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.rcfile.use.explicit.header</name>
+		<value>true</value>
+		<description>
+			If this is set the header for RC Files will simply be
+			RCF. If this is
+			not
+			set the header will be that borrowed from sequence
+			files, e.g. SEQ-
+			followed
+			by the input and output RC File formats.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.multi.insert.move.tasks.share.dependencies</name>
+		<value>false</value>
+		<description>
+			If this is set all move tasks for tables/partitions (not
+			directories)
+			at the end of a
+			multi-insert query will only begin once
+			the dependencies for all these move tasks
+			have been
+			met.
+			Advantages: If
+			concurrency is enabled, the locks will only be released once the
+			query has
+			finished, so with this config enabled, the time when the
+			table/partition is
+			generated will be much closer to when the lock on
+			it is released.
+			Disadvantages: If concurrency is not enabled, with
+			this disabled, the
+			tables/partitions which
+			are produced by this query
+			and finish earlier will be available for
+			querying
+			much earlier. Since
+			the locks are only released once the query finishes,
+			this
+			does not
+			apply if concurrency is enabled.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.fetch.task.conversion</name>
+		<value>minimal</value>
+		<description>
+			Some select queries can be converted to single FETCH task
+			minimizing
+			latency.
+			Currently the query should be single sourced not
+			having any subquery and
+			should not have
+			any aggregations or distincts
+			(which incurrs RS), lateral views and
+			joins.
+			1. minimal : SELECT STAR,
+			FILTER on partition columns, LIMIT only
+			2. more : SELECT, FILTER,
+			LIMIT only (TABLESAMPLE, virtual columns)
+		</description>
+	</property>
+
+	<property>
+		<name>hive.hmshandler.retry.attempts</name>
+		<value>1</value>
+		<description>The number of times to retry a HMSHandler call if there
+			were a connection error
+		</description>
+	</property>
+
+	<property>
+		<name>hive.hmshandler.retry.interval</name>
+		<value>1000</value>
+		<description>The number of miliseconds between HMSHandler retry
+			attempts
+		</description>
+	</property>
+
+	<property>
+		<name>hive.server.read.socket.timeout</name>
+		<value>10</value>
+		<description>Timeout for the HiveServer to close the connection if no
+			response from the client in N seconds, defaults to 10 seconds.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.server.tcp.keepalive</name>
+		<value>true</value>
+		<description>Whether to enable TCP keepalive for the Hive server.
+			Keepalive will prevent accumulation of half-open connections.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.decode.partition.name</name>
+		<value>false</value>
+		<description>Whether to show the unquoted partition names in query
+			results.
+		</description>
+	</property>
+
+	<property>
+		<name>hive.log4j.file</name>
+		<value></value>
+		<description>Hive log4j configuration file.
+			If the property is not set,
+			then logging will be initialized using
+			hive-log4j.properties found on
+			the classpath.
+			If the property is set, the value must be a valid URI
+			(java.net.URI,
+			e.g. "file:///tmp/my-logging.properties"), which you
+			can then extract
+			a URL from and pass to
+			PropertyConfigurator.configure(URL).
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.log4j.file</name>
+		<value></value>
+		<description>Hive log4j configuration file for execution mode(sub
+			command).
+			If the property is not set, then logging will be initialized
+			using
+			hive-exec-log4j.properties found on the classpath.
+			If the
+			property is set, the value must be a valid URI (java.net.URI,
+			e.g.
+			"file:///tmp/my-logging.properties"), which you can then extract
+			a URL
+			from and pass to PropertyConfigurator.configure(URL).
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.infer.bucket.sort</name>
+		<value>false</value>
+		<description>
+			If this is set, when writing partitions, the metadata
+			will include the
+			bucketing/sorting
+			properties with which the data was
+			written if any (this will not overwrite the
+			metadata
+			inherited from the
+			table if the table is bucketed/sorted)
+		</description>
+	</property>
+
+	<property>
+		<name>hive.exec.infer.bucket.sort.num.buckets.power.two</name>
+		<value>false</value>
+		<description>
+			If this is set, when setting the number of reducers for
+			the map reduce
+			task which writes the
+			final output files, it will choose
+			a number which is a power of two,
+			unless the user specifies
+			the number
+			of reducers to use using mapred.reduce.tasks. The number of
+			reducers
+			may be set to a power of two, only to be followed by a merge task
+			meaning preventing
+			anything from being inferred.
+			With
+			hive.exec.infer.bucket.sort set to true:
+			Advantages: If this is not
+			set, the number of buckets for partitions will seem
+			arbitrary,
+			which
+			means that the number of mappers used for optimized joins, for
+			example, will
+			be very low. With this set, since the number of buckets
+			used for any
+			partition is
+			a power of two, the number of mappers used
+			for optimized joins will be
+			the least
+			number of buckets used by any
+			partition being joined.
+			Disadvantages: This may mean a much larger or
+			much smaller number of reducers being
+			used in the
+			final map reduce job,
+			e.g. if a job was originally going to take 257
+			reducers,
+			it will now
+			take 512 reducers, similarly if the max number of reducers
+			is 511,
+			and
+			a job was going to use this many, it will now use 256 reducers.
+
+		</description>
+	</property>
+
+	<property>
+		<name>hive.groupby.orderby.position.alias</name>
+		<value>false</value>
+		<description>Whether to enable using Column Position Alias in Group By
+			or Order By
+		</description>
+	</property>
+
+	<property>
+		<name>hive.server2.thrift.min.worker.threads</name>
+		<value>5</value>
+		<description>Minimum number of Thrift worker threads</description>
+	</property>
+
+	<property>
+		<name>hive.server2.thrift.max.worker.threads</name>
+		<value>100</value>
+		<description>Maximum number of Thrift worker threads</description>
+	</property>
+
+	<property>
+		<name>hive.server2.thrift.port</name>
+		<value>10000</value>
+		<description>Port number of HiveServer2 Thrift interface.
+			Can be
+			overridden by setting $HIVE_SERVER2_THRIFT_PORT
+		</description>
+	</property>
+
+	<property>
+		<name>hive.server2.thrift.bind.host</name>
+		<value>localhost</value>
+		<description>Bind host on which to run the HiveServer2 Thrift
+			interface.
+			Can be overridden by setting $HIVE_SERVER2_THRIFT_BIND_HOST
+		</description>
+	</property>
+
+	<property>
+		<name>hive.server2.authentication</name>
+		<value>NONE</value>
+		<description>
+			Client authentication types.
+			NONE: no authentication check
+			LDAP: LDAP/AD based authentication
+			KERBEROS: Kerberos/GSSAPI
+			authentication
+			CUSTOM: Custom authentication provider
+			(Use with
+			property hive.server2.custom.authentication.class)
+		</description>
+	</property>
+
+	<property>
+		<name>hive.server2.custom.authentication.class</name>
+		<value></value>
+		<description>
+			Custom authentication class. Used when property
+			'hive.server2.authentication' is set to 'CUSTOM'. Provided class
+			must
+			be a proper implementation of the interface
+			org.apache.hive.service.auth.PasswdAuthenticationProvider.
+			HiveServer2
+			will call its Authenticate(user, passed) method to
+			authenticate requests.
+			The implementation may optionally extend the
+			Hadoop's
+			org.apache.hadoop.conf.Configured class to grab Hive's
+			Configuration
+			object.
+		</description>
+	</property>
+
+	<property>
+		<name>>hive.server2.authentication.kerberos.principal</name>
+		<value></value>
+		<description>
+			Kerberos server principal
+		</description>
+	</property>
+
+	<property>
+		<name>>hive.server2.authentication.kerberos.keytab</name>
+		<value></value>
+		<description>
+			Kerberos keytab file for server principal
+		</description>
+	</property>
+
+	<property>
+		<name>hive.server2.authentication.ldap.url</name>
+		<value></value>
+		<description>
+			LDAP connection URL
+		</description>
+	</property>
+
+	<property>
+		<name>hive.server2.authentication.ldap.baseDN</name>
+		<value></value>
+		<description>
+			LDAP base DN
+		</description>
+	</property>
+
+	<property>
+		<name>hive.server2.enable.doAs</name>
+		<value>true</value>
+		<description>
+			Setting this property to true will have hive server2
+			execute
+			hive operations as the user making the calls to it.
+		</description>
+	</property>
+
+
+</configuration>
diff --git a/hivesterix/hivesterix-dist/src/main/resources/scripts/copylog.sh b/hivesterix/hivesterix-dist/src/main/resources/scripts/copylog.sh
new file mode 100644
index 0000000..7767b2d
--- /dev/null
+++ b/hivesterix/hivesterix-dist/src/main/resources/scripts/copylog.sh
@@ -0,0 +1,7 @@
+. conf/cluster.properties
+
+NODEID=`hostname | cut -d '.' -f 1`
+#echo $NODEID
+
+#echo "rsync ${NCLOGS_DIR}/${NODEID}.log ${1}:${2}"
+rsync ${NCLOGS_DIR}/${NODEID}.log ${1}:${2}
diff --git a/hivesterix/hivesterix-dist/src/main/resources/scripts/dumpAll.sh b/hivesterix/hivesterix-dist/src/main/resources/scripts/dumpAll.sh
new file mode 100644
index 0000000..e7d45e8
--- /dev/null
+++ b/hivesterix/hivesterix-dist/src/main/resources/scripts/dumpAll.sh
@@ -0,0 +1,12 @@
+. conf/cluster.properties
+PREGELIX_PATH=`pwd`
+LOG_PATH=$PREGELIX_PATH/logs/
+rm -rf $LOG_PATH
+mkdir $LOG_PATH
+ccname=`hostname`
+
+for i in `cat conf/slaves`
+do
+   ssh $i "cd ${PREGELIX_PATH}; bin/dumptrace.sh; bin/copylog.sh ${ccname} ${LOG_PATH}"
+done
+
diff --git a/hivesterix/hivesterix-dist/src/main/resources/scripts/dumptrace.sh b/hivesterix/hivesterix-dist/src/main/resources/scripts/dumptrace.sh
new file mode 100644
index 0000000..9fe55f0
--- /dev/null
+++ b/hivesterix/hivesterix-dist/src/main/resources/scripts/dumptrace.sh
@@ -0,0 +1,15 @@
+echo `hostname`
+#Kill process
+PID=`ps -ef|grep ${USER}|grep java|grep 'Dapp.name=pregelixnc'|awk '{print $2}'`
+
+if [ "$PID" == "" ]; then
+  PID=`ps -ef|grep ${USER}|grep java|grep 'hyracks'|awk '{print $2}'`
+fi
+
+if [ "$PID" == "" ]; then
+  USERID=`id | sed 's/^uid=//;s/(.*$//'`
+  PID=`ps -ef|grep ${USERID}|grep java|grep 'Dapp.name=pregelixnc'|awk '{print $2}'`
+fi
+
+echo $PID
+kill -QUIT $PID
diff --git a/hivesterix/hivesterix-dist/src/main/resources/scripts/hive b/hivesterix/hivesterix-dist/src/main/resources/scripts/hive
index 38a9e33..d2ef909 100755
--- a/hivesterix/hivesterix-dist/src/main/resources/scripts/hive
+++ b/hivesterix/hivesterix-dist/src/main/resources/scripts/hive
@@ -175,13 +175,6 @@
     exit 5
 fi
 
-if [ $hadoop_minor_ver -ne 20 -o $hadoop_patch_ver -eq 0 ]; then
-    echo "Hive requires Hadoop 0.20.x (x >= 1)."
-    echo "'hadoop version' returned:"
-    echo `$HADOOP version`
-    exit 6
-fi
-
 if [ "${AUX_PARAM}" != "" ]; then
   HIVE_OPTS="$HIVE_OPTS -hiveconf hive.aux.jars.path=${AUX_PARAM}"
   AUX_JARS_CMD_LINE="-libjars ${AUX_PARAM}"
diff --git a/hivesterix/hivesterix-dist/src/test/java/edu/uci/ics/hivesterix/test/runtimefunction/RuntimeFunctionTestSuite.java b/hivesterix/hivesterix-dist/src/test/java/edu/uci/ics/hivesterix/test/runtimefunction/RuntimeFunctionTestSuite.java
index b024269..5fdfb3a 100644
--- a/hivesterix/hivesterix-dist/src/test/java/edu/uci/ics/hivesterix/test/runtimefunction/RuntimeFunctionTestSuite.java
+++ b/hivesterix/hivesterix-dist/src/test/java/edu/uci/ics/hivesterix/test/runtimefunction/RuntimeFunctionTestSuite.java
@@ -12,77 +12,77 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package edu.uci.ics.hivesterix.test.runtimefunction;
-
-import java.io.File;
-import java.util.List;
-
-import junit.framework.Test;
-import junit.framework.TestResult;
-import edu.uci.ics.hivesterix.test.base.AbstractTestSuiteClass;
-
-public class RuntimeFunctionTestSuite extends AbstractTestSuiteClass {
-
-    private static final String PATH_TO_QUERIES = "src/test/resources/runtimefunctionts/queries/";
-    private static final String PATH_TO_RESULTS = "src/test/resources/runtimefunctionts/results/";
-    private static final String PATH_TO_IGNORES = "src/test/resources/runtimefunctionts/ignore.txt";
-
-    private static final String FILE_EXTENSION_OF_RESULTS = "result";
-
-    public static Test suite() throws Exception {
-        List<String> ignores = getIgnoreList(PATH_TO_IGNORES);
-        File testData = new File(PATH_TO_QUERIES);
-        File[] queries = testData.listFiles();
-        RuntimeFunctionTestSuite testSuite = new RuntimeFunctionTestSuite();
-
-        // set hdfs and hyracks cluster, and load test data to hdfs
-        try {
-            testSuite.setup();
-            testSuite.loadData();
-        } catch (Exception e) {
-            e.printStackTrace();
-            throw new IllegalStateException(e.getMessage());
-        }
-
-        for (File qFile : queries) {
-            if (isIgnored(qFile.getName(), ignores))
-                continue;
-
-            if (qFile.isFile()) {
-                String resultFileName = hiveExtToResExt(qFile.getName());
-                File rFile = new File(PATH_TO_RESULTS + resultFileName);
-                testSuite.addTest(new RuntimeFunctionTestCase(qFile, rFile));
-            }
-        }
-        return testSuite;
-    }
-
-    private static String hiveExtToResExt(String fname) {
-        int dot = fname.lastIndexOf('.');
-        return fname.substring(0, dot + 1) + FILE_EXTENSION_OF_RESULTS;
-    }
-
-    /**
-     * Runs the tests and collects their result in a TestResult.
-     */
-    @Override
-    public void run(TestResult result) {
-
-        int testCount = countTestCases();
-        for (int i = 0; i < testCount; i++) {
-            Test each = this.testAt(i);
-            if (result.shouldStop())
-                break;
-            runTest(each, result);
-        }
-
-        // cleanup hdfs and hyracks cluster
-        try {
-            cleanup();
-        } catch (Exception e) {
-            e.printStackTrace();
-            throw new IllegalStateException(e.getMessage());
-        }
-    }
-
-}
+package edu.uci.ics.hivesterix.test.runtimefunction;
+
+import java.io.File;
+import java.util.List;
+
+import junit.framework.Test;
+import junit.framework.TestResult;
+import edu.uci.ics.hivesterix.test.base.AbstractTestSuiteClass;
+
+public class RuntimeFunctionTestSuite extends AbstractTestSuiteClass {
+
+    private static final String PATH_TO_QUERIES = "src/test/resources/runtimefunctionts/queries/";
+    private static final String PATH_TO_RESULTS = "src/test/resources/runtimefunctionts/results/";
+    private static final String PATH_TO_IGNORES = "src/test/resources/runtimefunctionts/ignore.txt";
+
+    private static final String FILE_EXTENSION_OF_RESULTS = "result";
+
+    public static Test suite() throws Exception {
+        List<String> ignores = getIgnoreList(PATH_TO_IGNORES);
+        File testData = new File(PATH_TO_QUERIES);
+        File[] queries = testData.listFiles();
+        RuntimeFunctionTestSuite testSuite = new RuntimeFunctionTestSuite();
+
+        // set hdfs and hyracks cluster, and load test data to hdfs
+        try {
+            testSuite.setup();
+            testSuite.loadData();
+        } catch (Exception e) {
+            e.printStackTrace();
+            throw new IllegalStateException(e.getMessage());
+        }
+
+        for (File qFile : queries) {
+            if (isIgnored(qFile.getName(), ignores))
+                continue;
+
+            if (qFile.isFile()) {
+                String resultFileName = hiveExtToResExt(qFile.getName());
+                File rFile = new File(PATH_TO_RESULTS + resultFileName);
+                testSuite.addTest(new RuntimeFunctionTestCase(qFile, rFile));
+            }
+        }
+        return testSuite;
+    }
+
+    private static String hiveExtToResExt(String fname) {
+        int dot = fname.lastIndexOf('.');
+        return fname.substring(0, dot + 1) + FILE_EXTENSION_OF_RESULTS;
+    }
+
+    /**
+     * Runs the tests and collects their result in a TestResult.
+     */
+    @Override
+    public void run(TestResult result) {
+
+        int testCount = countTestCases();
+        for (int i = 0; i < testCount; i++) {
+            Test each = this.testAt(i);
+            if (result.shouldStop())
+                break;
+            runTest(each, result);
+        }
+
+        // cleanup hdfs and hyracks cluster
+        try {
+            cleanup();
+        } catch (Exception e) {
+            e.printStackTrace();
+            throw new IllegalStateException(e.getMessage());
+        }
+    }
+
+}
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q10_returned_item.hive b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q10_returned_item.hive
index 3f1214a..bb07665 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q10_returned_item.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q10_returned_item.hive
@@ -13,9 +13,6 @@
 -- create the result table
 create table q10_returned_item (c_custkey int, c_name string, revenue double, c_acctbal string, n_name string, c_address string, c_phone string, c_comment string);
 
-set mapred.min.split.size=536870912;
-set hive.exec.reducers.bytes.per.reducer=1024000000;
-
 -- the query
 insert overwrite table q10_returned_item
 select 
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q12_shipping.hive b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q12_shipping.hive
index 062f7b9..ae2fa3a 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q12_shipping.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q12_shipping.hive
@@ -9,8 +9,6 @@
 -- create the result table
 create table q12_shipping(l_shipmode string, high_line_count double, low_line_count double);
 
-set mapred.min.split.size=536870912;
-set hive.exec.reducers.bytes.per.reducer=1225000000;
 
 -- the query
 insert overwrite table q12_shipping
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q14_promotion_effect.hive b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q14_promotion_effect.hive
index 988f400..4644d23 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q14_promotion_effect.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q14_promotion_effect.hive
@@ -9,9 +9,6 @@
 -- create the result table
 create table q14_promotion_effect(promo_revenue double);
 
-set mapred.min.split.size=536870912;
-set hive.exec.reducers.bytes.per.reducer=1040000000;
-
 -- the query
 insert overwrite table q14_promotion_effect
 select 
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q15_top_supplier.hive b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q15_top_supplier.hive
index 04064ed..8fa333e 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q15_top_supplier.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q15_top_supplier.hive
@@ -14,8 +14,6 @@
 create table q15_top_supplier(s_suppkey int, s_name string, s_address string, s_phone string, total_revenue double);
 
 
-set mapred.min.split.size=536870912;
-
 -- the query
 insert overwrite table revenue
 select 
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q18_large_volume_customer.hive b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q18_large_volume_customer.hive
index 76d0475..c617c26 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q18_large_volume_customer.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q18_large_volume_customer.hive
@@ -13,8 +13,6 @@
 create table q18_tmp(l_orderkey int, t_sum_quantity double);
 create table q18_large_volume_customer(c_name string, c_custkey int, o_orderkey int, o_orderdate string, o_totalprice double, sum_quantity double);
 
-set mapred.min.split.size=268435456;
-set hive.exec.reducers.bytes.per.reducer=1164000000;
 
 -- the query
 insert overwrite table q18_tmp
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q19_discounted_revenue.hive b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q19_discounted_revenue.hive
index fd330cd..a7a0a0a 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q19_discounted_revenue.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q19_discounted_revenue.hive
@@ -9,8 +9,6 @@
 -- create the result table
 create table q19_discounted_revenue(revenue double);
 
-set mapred.min.split.size=268435456;
-set hive.exec.reducers.bytes.per.reducer=1040000000;
 
 -- the query
 insert overwrite table q19_discounted_revenue
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q1_pricing_summary_report.hive b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q1_pricing_summary_report.hive
index a002068..af64a4f 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q1_pricing_summary_report.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q1_pricing_summary_report.hive
@@ -7,8 +7,6 @@
 -- create the target table
 CREATE TABLE q1_pricing_summary_report ( L_RETURNFLAG STRING, L_LINESTATUS STRING, SUM_QTY DOUBLE, SUM_BASE_PRICE DOUBLE, SUM_DISC_PRICE DOUBLE, SUM_CHARGE DOUBLE, AVE_QTY DOUBLE, AVE_PRICE DOUBLE, AVE_DISC DOUBLE, COUNT_ORDER INT);
 
-set mapred.min.split.size=536870912;
-
 -- the query
 INSERT OVERWRITE TABLE q1_pricing_summary_report 
 SELECT 
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q20_potential_part_promotion.hive b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q20_potential_part_promotion.hive
index 63297e6..3149962 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q20_potential_part_promotion.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q20_potential_part_promotion.hive
@@ -22,7 +22,6 @@
 create table q20_tmp4(ps_suppkey int);
 create table q20_potential_part_promotion(s_name string, s_address string);
 
-set mapred.min.split.size=536870912;
 
 -- the query
 insert overwrite table q20_tmp1
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q3_shipping_priority.hive b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q3_shipping_priority.hive
index 0049eb3..67f6dc4 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q3_shipping_priority.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q3_shipping_priority.hive
@@ -11,9 +11,6 @@
 -- create the target table
 create table q3_shipping_priority (l_orderkey int, revenue double, o_orderdate string, o_shippriority int);
 
-set mapred.min.split.size=536870912;
-set hive.exec.reducers.bytes.per.reducer=1024000000;
-
 -- the query
 Insert overwrite table q3_shipping_priority 
 select 
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q4_order_priority.hive b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q4_order_priority.hive
index aa828e9..efbcff2 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q4_order_priority.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q4_order_priority.hive
@@ -11,7 +11,6 @@
 CREATE TABLE q4_order_priority_tmp (O_ORDERKEY INT);
 CREATE TABLE q4_order_priority (O_ORDERPRIORITY STRING, ORDER_COUNT INT);
 
-set mapred.min.split.size=536870912;
 -- the query
 INSERT OVERWRITE TABLE q4_order_priority_tmp 
 select 
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q5_local_supplier_volume.hive b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q5_local_supplier_volume.hive
index a975ce1..091f000 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q5_local_supplier_volume.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q5_local_supplier_volume.hive
@@ -17,7 +17,6 @@
 -- create the target table
 create table q5_local_supplier_volume (N_NAME STRING, REVENUE DOUBLE);
 
-set mapred.min.split.size=536870912;
 
 -- the query
 insert overwrite table q5_local_supplier_volume 
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q7_volume_shipping.hive b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q7_volume_shipping.hive
index 3dfb22a..444644f 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q7_volume_shipping.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q7_volume_shipping.hive
@@ -17,8 +17,6 @@
 create table q7_volume_shipping (supp_nation string, cust_nation string, l_year int, revenue double);
 create table q7_volume_shipping_tmp(supp_nation string, cust_nation string, s_nationkey int, c_nationkey int);
 
-set mapred.min.split.size=536870912;
-set hive.exec.reducers.bytes.per.reducer=1225000000;
 
 -- the query
 insert overwrite table q7_volume_shipping_tmp
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q9_product_type_profit.hive b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q9_product_type_profit.hive
index 586779c..a9bb58b 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q9_product_type_profit.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/q9_product_type_profit.hive
@@ -17,8 +17,6 @@
 -- create the result table
 create table q9_product_type_profit (nation string, o_year string, sum_profit double);
 
-set mapred.min.split.size=536870912;
-set hive.exec.reducers.bytes.per.reducer=1024000000;
 
 -- the query
 insert overwrite table q9_product_type_profit
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/u7_multi_join.hive b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/u7_multi_join.hive
index 2891c56..70b3538 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/u7_multi_join.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/queries/u7_multi_join.hive
@@ -6,4 +6,7 @@
 create external table orders (O_ORDERKEY INT, O_CUSTKEY INT, O_ORDERSTATUS STRING, O_TOTALPRICE DOUBLE, O_ORDERDATE STRING, O_ORDERPRIORITY STRING, O_CLERK STRING, O_SHIPPRIORITY INT, O_COMMENT STRING) ROW FORMAT DELIMITED FIELDS TERMINATED BY '|' STORED AS TEXTFILE LOCATION '/tpch/orders';
 create external table customer (C_CUSTKEY INT, C_NAME STRING, C_ADDRESS STRING, C_NATIONKEY INT, C_PHONE STRING, C_ACCTBAL DOUBLE, C_MKTSEGMENT STRING, C_COMMENT STRING) ROW FORMAT DELIMITED FIELDS TERMINATED BY '|' STORED AS TEXTFILE LOCATION '/tpch/customer';
 
-select l_linenumber, o_orderkey, o_totalprice, o_orderdate, o_shippriority from  customer c join orders o  on c.c_custkey = o.o_custkey join lineitem l    on o.o_orderkey = l.l_orderkey  where c.c_custkey<5 and o.o_totalprice<30000;
+select l_linenumber, o_orderkey, o_totalprice, o_orderdate, o_shippriority from 
+ customer c join orders o  on c.c_custkey = o.o_custkey 
+ join lineitem l    on o.o_orderkey = l.l_orderkey  
+ where c.c_custkey<5 and o.o_totalprice<30000;
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q10_returned_item.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q10_returned_item.plan
index 05b3718..bda1113 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q10_returned_item.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q10_returned_item.plan
@@ -1,5 +1,5 @@
 write [%0->$$38, %0->$$39, %0->$$45, %0->$$40, %0->$$42, %0->$$43, %0->$$41, %0->$$44]
--- SINK_WRITE  |UNPARTITIONED|
+-- SINK_WRITE  |PARTITIONED|
   project ([$$38, $$39, $$45, $$40, $$42, $$43, $$41, $$44])
   -- STREAM_PROJECT  |PARTITIONED|
     limit 20
@@ -9,11 +9,11 @@
         exchange 
         -- SORT_MERGE_EXCHANGE [$$45(DESC) ]  |PARTITIONED|
           limit 20
-          -- STREAM_LIMIT  |LOCAL|
+          -- STREAM_LIMIT  |PARTITIONED|
             exchange 
-            -- ONE_TO_ONE_EXCHANGE  |LOCAL|
+            -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
               order (DESC, %0->$$45) 
-              -- STABLE_SORT [$$45(DESC)]  |LOCAL|
+              -- STABLE_SORT [$$45(DESC)]  |PARTITIONED|
                 exchange 
                 -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                   group by ([$$38 := %0->$$48; $$39 := %0->$$49; $$40 := %0->$$50; $$41 := %0->$$51; $$42 := %0->$$52; $$43 := %0->$$53; $$44 := %0->$$54]) decor ([]) {
@@ -31,7 +31,7 @@
                                   nested tuple source
                                   -- NESTED_TUPLE_SOURCE  |LOCAL|
                              }
-                      -- EXTERNAL_GROUP_BY[$$21, $$22, $$26, $$25, $$18, $$23, $$28]  |LOCAL|
+                      -- EXTERNAL_GROUP_BY[$$21, $$22, $$26, $$25, $$18, $$23, $$28]  |PARTITIONED|
                         exchange 
                         -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                           project ([$$21, $$22, $$23, $$25, $$26, $$28, $$18, $$6, $$7])
@@ -82,7 +82,7 @@
                                                 -- HASH_PARTITION_EXCHANGE [$$30]  |PARTITIONED|
                                                   project ([$$30, $$29])
                                                   -- STREAM_PROJECT  |PARTITIONED|
-                                                    select (function-call: algebricks:and, Args:[function-call: algebricks:lt, Args:[%0->$$33, 1994-01-01], function-call: algebricks:ge, Args:[%0->$$33, 1993-10-01], function-call: algebricks:lt, Args:[%0->$$33, 1994-01-01]])
+                                                    select (function-call: algebricks:and, Args:[function-call: algebricks:ge, Args:[%0->$$33, 1993-10-01], function-call: algebricks:lt, Args:[%0->$$33, 1994-01-01]])
                                                     -- STREAM_SELECT  |PARTITIONED|
                                                       exchange 
                                                       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
@@ -99,4 +99,4 @@
                                                     exchange 
                                                     -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                                                       empty-tuple-source
-                                                      -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                                                      -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q11_important_stock.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q11_important_stock.plan
index 70ad7ee..8195ef0 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q11_important_stock.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q11_important_stock.plan
@@ -19,7 +19,7 @@
                       nested tuple source
                       -- NESTED_TUPLE_SOURCE  |LOCAL|
                  }
-          -- EXTERNAL_GROUP_BY[$$1]  |LOCAL|
+          -- EXTERNAL_GROUP_BY[$$1]  |PARTITIONED|
             exchange 
             -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
               project ([$$1, $$3, $$4])
@@ -85,7 +85,7 @@
                     nested tuple source
                     -- NESTED_TUPLE_SOURCE  |LOCAL|
                }
-        -- EXTERNAL_GROUP_BY[]  |LOCAL|
+        -- EXTERNAL_GROUP_BY[]  |PARTITIONED|
           exchange 
           -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
             data-scan [$$2]<-[$$1, $$2] <- default.q11_part_tmp
@@ -99,7 +99,7 @@
   exchange 
   -- SORT_MERGE_EXCHANGE [$$3(DESC) ]  |PARTITIONED|
     order (DESC, %0->$$3) 
-    -- STABLE_SORT [$$3(DESC)]  |LOCAL|
+    -- STABLE_SORT [$$3(DESC)]  |PARTITIONED|
       exchange 
       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
         project ([$$2, $$3])
@@ -123,4 +123,4 @@
                   exchange 
                   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                     empty-tuple-source
-                    -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                    -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q12_shipping.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q12_shipping.plan
index 5c240e2..d976bba 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q12_shipping.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q12_shipping.plan
@@ -7,7 +7,7 @@
       exchange 
       -- SORT_MERGE_EXCHANGE [$$26(ASC) ]  |PARTITIONED|
         order (ASC, %0->$$26) 
-        -- STABLE_SORT [$$26(ASC)]  |LOCAL|
+        -- STABLE_SORT [$$26(ASC)]  |PARTITIONED|
           exchange 
           -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
             group by ([$$26 := %0->$$34]) decor ([]) {
@@ -25,7 +25,7 @@
                             nested tuple source
                             -- NESTED_TUPLE_SOURCE  |LOCAL|
                        }
-                -- EXTERNAL_GROUP_BY[$$24]  |LOCAL|
+                -- EXTERNAL_GROUP_BY[$$24]  |PARTITIONED|
                   exchange 
                   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                     project ([$$6, $$24])
@@ -38,7 +38,7 @@
                           -- HASH_PARTITION_EXCHANGE [$$10]  |PARTITIONED|
                             project ([$$10, $$24])
                             -- STREAM_PROJECT  |PARTITIONED|
-                              select (function-call: algebricks:and, Args:[function-call: algebricks:lt, Args:[%0->$$22, 1995-01-01], function-call: algebricks:ge, Args:[%0->$$22, 1994-01-01], function-call: algebricks:lt, Args:[%0->$$20, %0->$$21], function-call: algebricks:lt, Args:[%0->$$21, %0->$$22], function-call: algebricks:lt, Args:[%0->$$20, %0->$$21], function-call: algebricks:ge, Args:[%0->$$22, 1994-01-01], function-call: algebricks:lt, Args:[%0->$$22, 1995-01-01], function-call: algebricks:or, Args:[function-call: algebricks:eq, Args:[%0->$$24, MAIL], function-call: algebricks:eq, Args:[%0->$$24, SHIP]], function-call: algebricks:or, Args:[function-call: algebricks:eq, Args:[%0->$$24, MAIL], function-call: algebricks:eq, Args:[%0->$$24, SHIP]]])
+                              select (function-call: algebricks:and, Args:[function-call: algebricks:lt, Args:[%0->$$21, %0->$$22], function-call: algebricks:lt, Args:[%0->$$20, %0->$$21], function-call: algebricks:ge, Args:[%0->$$22, 1994-01-01], function-call: algebricks:lt, Args:[%0->$$22, 1995-01-01], function-call: algebricks:or, Args:[function-call: algebricks:eq, Args:[%0->$$24, MAIL], function-call: algebricks:eq, Args:[%0->$$24, SHIP]]])
                               -- STREAM_SELECT  |PARTITIONED|
                                 exchange 
                                 -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
@@ -55,4 +55,4 @@
                               exchange 
                               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                                 empty-tuple-source
-                                -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                                -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q13_customer_distribution.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q13_customer_distribution.plan
index 19bcd24..40cedd6 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q13_customer_distribution.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q13_customer_distribution.plan
@@ -7,74 +7,65 @@
       exchange 
       -- SORT_MERGE_EXCHANGE [$$21(DESC), $$20(DESC) ]  |PARTITIONED|
         order (DESC, %0->$$21) (DESC, %0->$$20) 
-        -- STABLE_SORT [$$21(DESC), $$20(DESC)]  |LOCAL|
+        -- STABLE_SORT [$$21(DESC), $$20(DESC)]  |PARTITIONED|
           exchange 
           -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-            group by ([$$20 := %0->$$28]) decor ([]) {
-                      aggregate [$$21] <- [function-call: hive:count(FINAL), Args:[%0->$$27]]
+            group by ([$$20 := %0->$$26]) decor ([]) {
+                      aggregate [$$21] <- [function-call: hive:count(FINAL), Args:[%0->$$25]]
                       -- AGGREGATE  |LOCAL|
                         nested tuple source
                         -- NESTED_TUPLE_SOURCE  |LOCAL|
                    }
-            -- EXTERNAL_GROUP_BY[$$28]  |PARTITIONED|
+            -- EXTERNAL_GROUP_BY[$$26]  |PARTITIONED|
               exchange 
-              -- HASH_PARTITION_EXCHANGE [$$28]  |PARTITIONED|
-                group by ([$$28 := %0->$$19]) decor ([]) {
-                          aggregate [$$27] <- [function-call: hive:count(PARTIAL1), Args:[1]]
+              -- HASH_PARTITION_EXCHANGE [$$26]  |PARTITIONED|
+                group by ([$$26 := %0->$$19]) decor ([]) {
+                          aggregate [$$25] <- [function-call: hive:count(PARTIAL1), Args:[1]]
                           -- AGGREGATE  |LOCAL|
                             nested tuple source
                             -- NESTED_TUPLE_SOURCE  |LOCAL|
                        }
-                -- EXTERNAL_GROUP_BY[$$19]  |LOCAL|
+                -- EXTERNAL_GROUP_BY[$$19]  |PARTITIONED|
                   exchange 
                   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                     project ([$$19])
                     -- STREAM_PROJECT  |PARTITIONED|
                       exchange 
                       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                        group by ([$$18 := %0->$$26]) decor ([]) {
-                                  aggregate [$$19] <- [function-call: hive:count(FINAL), Args:[%0->$$25]]
+                        group by ([$$18 := %0->$$10]) decor ([]) {
+                                  aggregate [$$19] <- [function-call: hive:count(COMPLETE), Args:[%0->$$1]]
                                   -- AGGREGATE  |LOCAL|
                                     nested tuple source
                                     -- NESTED_TUPLE_SOURCE  |LOCAL|
                                }
-                        -- EXTERNAL_GROUP_BY[$$26]  |PARTITIONED|
+                        -- EXTERNAL_GROUP_BY[$$10]  |PARTITIONED|
                           exchange 
-                          -- HASH_PARTITION_EXCHANGE [$$26]  |PARTITIONED|
-                            group by ([$$26 := %0->$$10]) decor ([]) {
-                                      aggregate [$$25] <- [function-call: hive:count(PARTIAL1), Args:[%0->$$1]]
-                                      -- AGGREGATE  |LOCAL|
-                                        nested tuple source
-                                        -- NESTED_TUPLE_SOURCE  |LOCAL|
-                                   }
-                            -- EXTERNAL_GROUP_BY[$$10]  |LOCAL|
+                          -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                            project ([$$10, $$1])
+                            -- STREAM_PROJECT  |PARTITIONED|
                               exchange 
                               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                                project ([$$10, $$1])
-                                -- STREAM_PROJECT  |PARTITIONED|
+                                left outer join (function-call: algebricks:eq, Args:[%0->$$2, %0->$$10])
+                                -- HYBRID_HASH_JOIN [$$10][$$2]  |PARTITIONED|
                                   exchange 
-                                  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                                    left outer join (function-call: algebricks:eq, Args:[%0->$$2, %0->$$10])
-                                    -- HYBRID_HASH_JOIN [$$10][$$2]  |PARTITIONED|
+                                  -- HASH_PARTITION_EXCHANGE [$$10]  |PARTITIONED|
+                                    data-scan [$$10]<-[$$10, $$11, $$12, $$13, $$14, $$15, $$16, $$17] <- default.customer
+                                    -- DATASOURCE_SCAN  |PARTITIONED|
                                       exchange 
-                                      -- HASH_PARTITION_EXCHANGE [$$10]  |PARTITIONED|
-                                        data-scan [$$10]<-[$$10, $$11, $$12, $$13, $$14, $$15, $$16, $$17] <- default.customer
-                                        -- DATASOURCE_SCAN  |PARTITIONED|
-                                          exchange 
-                                          -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                                            empty-tuple-source
-                                            -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
-                                      exchange 
-                                      -- HASH_PARTITION_EXCHANGE [$$2]  |PARTITIONED|
-                                        project ([$$2, $$1])
-                                        -- STREAM_PROJECT  |PARTITIONED|
-                                          select (function-call: algebricks:not, Args:[function-call: hive:org.apache.hadoop.hive.ql.udf.UDFLike, Args:[%0->$$9, %special%requests%]])
-                                          -- STREAM_SELECT  |PARTITIONED|
+                                      -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                                        empty-tuple-source
+                                        -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                                  exchange 
+                                  -- HASH_PARTITION_EXCHANGE [$$2]  |PARTITIONED|
+                                    project ([$$2, $$1])
+                                    -- STREAM_PROJECT  |PARTITIONED|
+                                      select (function-call: algebricks:not, Args:[function-call: hive:org.apache.hadoop.hive.ql.udf.UDFLike, Args:[%0->$$9, %special%requests%]])
+                                      -- STREAM_SELECT  |PARTITIONED|
+                                        exchange 
+                                        -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                                          data-scan [$$1, $$2, $$9]<-[$$1, $$2, $$3, $$4, $$5, $$6, $$7, $$8, $$9] <- default.orders
+                                          -- DATASOURCE_SCAN  |PARTITIONED|
                                             exchange 
                                             -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                                              data-scan [$$1, $$2, $$9]<-[$$1, $$2, $$3, $$4, $$5, $$6, $$7, $$8, $$9] <- default.orders
-                                              -- DATASOURCE_SCAN  |PARTITIONED|
-                                                exchange 
-                                                -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                                                  empty-tuple-source
-                                                  -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                                              empty-tuple-source
+                                              -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q14_promotion_effect.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q14_promotion_effect.plan
index 21b90bd..e6d1c1d 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q14_promotion_effect.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q14_promotion_effect.plan
@@ -21,7 +21,7 @@
                         nested tuple source
                         -- NESTED_TUPLE_SOURCE  |LOCAL|
                    }
-            -- EXTERNAL_GROUP_BY[]  |LOCAL|
+            -- EXTERNAL_GROUP_BY[]  |PARTITIONED|
               exchange 
               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                 project ([$$5, $$15, $$16])
@@ -34,7 +34,7 @@
                       -- HASH_PARTITION_EXCHANGE [$$11]  |PARTITIONED|
                         project ([$$11, $$15, $$16])
                         -- STREAM_PROJECT  |PARTITIONED|
-                          select (function-call: algebricks:and, Args:[function-call: algebricks:lt, Args:[%0->$$20, 1995-10-01], function-call: algebricks:ge, Args:[%0->$$20, 1995-09-01], function-call: algebricks:lt, Args:[%0->$$20, 1995-10-01]])
+                          select (function-call: algebricks:and, Args:[function-call: algebricks:ge, Args:[%0->$$20, 1995-09-01], function-call: algebricks:lt, Args:[%0->$$20, 1995-10-01]])
                           -- STREAM_SELECT  |PARTITIONED|
                             exchange 
                             -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
@@ -51,4 +51,4 @@
                           exchange 
                           -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                             empty-tuple-source
-                            -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                            -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q15_top_supplier.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q15_top_supplier.plan
index a5bd27a..c61ed37 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q15_top_supplier.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q15_top_supplier.plan
@@ -19,12 +19,12 @@
                       nested tuple source
                       -- NESTED_TUPLE_SOURCE  |LOCAL|
                  }
-          -- EXTERNAL_GROUP_BY[$$3]  |LOCAL|
+          -- EXTERNAL_GROUP_BY[$$3]  |PARTITIONED|
             exchange 
             -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
               project ([$$3, $$6, $$7])
               -- STREAM_PROJECT  |PARTITIONED|
-                select (function-call: algebricks:and, Args:[function-call: algebricks:ge, Args:[%0->$$11, 1996-01-01], function-call: algebricks:lt, Args:[%0->$$11, 1996-04-01], function-call: algebricks:ge, Args:[%0->$$11, 1996-01-01], function-call: algebricks:lt, Args:[%0->$$11, 1996-04-01]])
+                select (function-call: algebricks:and, Args:[function-call: algebricks:ge, Args:[%0->$$11, 1996-01-01], function-call: algebricks:lt, Args:[%0->$$11, 1996-04-01]])
                 -- STREAM_SELECT  |PARTITIONED|
                   exchange 
                   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
@@ -53,7 +53,7 @@
                     nested tuple source
                     -- NESTED_TUPLE_SOURCE  |LOCAL|
                }
-        -- PRE_CLUSTERED_GROUP_BY[]  |LOCAL|
+        -- PRE_CLUSTERED_GROUP_BY[]  |PARTITIONED|
           exchange 
           -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
             data-scan [$$2]<-[$$1, $$2] <- default.revenue
@@ -67,7 +67,7 @@
   exchange 
   -- SORT_MERGE_EXCHANGE [$$2(ASC) ]  |PARTITIONED|
     order (ASC, %0->$$2) 
-    -- STABLE_SORT [$$2(ASC)]  |LOCAL|
+    -- STABLE_SORT [$$2(ASC)]  |PARTITIONED|
       exchange 
       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
         project ([$$2, $$3, $$4, $$6, $$10])
@@ -107,4 +107,4 @@
                           exchange 
                           -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                             empty-tuple-source
-                            -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                            -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q16_parts_supplier_relationship.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q16_parts_supplier_relationship.plan
index 9835346..c986cb4 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q16_parts_supplier_relationship.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q16_parts_supplier_relationship.plan
@@ -38,7 +38,7 @@
               -- HYBRID_HASH_JOIN [$$2][$$11]  |PARTITIONED|
                 exchange 
                 -- HASH_PARTITION_EXCHANGE [$$2]  |PARTITIONED|
-                  select (function-call: algebricks:and, Args:[function-call: algebricks:not, Args:[function-call: hive:org.apache.hadoop.hive.ql.udf.UDFLike, Args:[%0->$$6, MEDIUM POLISHED%]], function-call: algebricks:neq, Args:[%0->$$5, Brand#45], function-call: algebricks:not, Args:[function-call: hive:org.apache.hadoop.hive.ql.udf.UDFLike, Args:[%0->$$6, MEDIUM POLISHED%]]])
+                  select (function-call: algebricks:and, Args:[function-call: algebricks:neq, Args:[%0->$$5, Brand#45], function-call: algebricks:not, Args:[function-call: hive:org.apache.hadoop.hive.ql.udf.UDFLike, Args:[%0->$$6, MEDIUM POLISHED%]]])
                   -- STREAM_SELECT  |PARTITIONED|
                     exchange 
                     -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
@@ -65,7 +65,7 @@
       exchange 
       -- SORT_MERGE_EXCHANGE [$$13(DESC), $$10(ASC), $$11(ASC), $$12(ASC) ]  |PARTITIONED|
         order (DESC, %0->$$13) (ASC, %0->$$10) (ASC, %0->$$11) (ASC, %0->$$12) 
-        -- STABLE_SORT [$$13(DESC), $$10(ASC), $$11(ASC), $$12(ASC)]  |LOCAL|
+        -- STABLE_SORT [$$13(DESC), $$10(ASC), $$11(ASC), $$12(ASC)]  |PARTITIONED|
           exchange 
           -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
             group by ([$$10 := %0->$$5; $$11 := %0->$$6; $$12 := %0->$$7]) decor ([]) {
@@ -95,4 +95,4 @@
                           exchange 
                           -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                             empty-tuple-source
-                            -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                            -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q17_small_quantity_order_revenue.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q17_small_quantity_order_revenue.plan
index a827007..8a75f64 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q17_small_quantity_order_revenue.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q17_small_quantity_order_revenue.plan
@@ -21,7 +21,7 @@
                         nested tuple source
                         -- NESTED_TUPLE_SOURCE  |LOCAL|
                    }
-            -- EXTERNAL_GROUP_BY[$$2]  |LOCAL|
+            -- EXTERNAL_GROUP_BY[$$2]  |PARTITIONED|
               exchange 
               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                 data-scan [$$2, $$5]<-[$$1, $$2, $$3, $$4, $$5, $$6, $$7, $$8, $$9, $$10, $$11, $$12, $$13, $$14, $$15, $$16] <- default.lineitem
@@ -53,13 +53,13 @@
                         nested tuple source
                         -- NESTED_TUPLE_SOURCE  |LOCAL|
                    }
-            -- EXTERNAL_GROUP_BY[]  |LOCAL|
+            -- EXTERNAL_GROUP_BY[]  |PARTITIONED|
               exchange 
               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                 project ([$$17])
                 -- STREAM_PROJECT  |PARTITIONED|
                   select (function-call: algebricks:lt, Args:[%0->$$16, %0->$$2])
-                  -- STREAM_SELECT  |UNPARTITIONED|
+                  -- STREAM_SELECT  |PARTITIONED|
                     exchange 
                     -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                       join (function-call: algebricks:eq, Args:[%0->$$13, %0->$$1])
@@ -84,7 +84,7 @@
                                 -- HASH_PARTITION_EXCHANGE [$$3]  |PARTITIONED|
                                   project ([$$3])
                                   -- STREAM_PROJECT  |PARTITIONED|
-                                    select (function-call: algebricks:and, Args:[function-call: algebricks:eq, Args:[%0->$$9, MED BOX], function-call: algebricks:eq, Args:[%0->$$6, Brand#23], function-call: algebricks:eq, Args:[%0->$$9, MED BOX]])
+                                    select (function-call: algebricks:and, Args:[function-call: algebricks:eq, Args:[%0->$$6, Brand#23], function-call: algebricks:eq, Args:[%0->$$9, MED BOX]])
                                     -- STREAM_SELECT  |PARTITIONED|
                                       exchange 
                                       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
@@ -101,4 +101,4 @@
                             exchange 
                             -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                               empty-tuple-source
-                              -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                              -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q18_large_volume_customer.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q18_large_volume_customer.plan
index ea47ea0..eb78f1d 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q18_large_volume_customer.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q18_large_volume_customer.plan
@@ -19,7 +19,7 @@
                       nested tuple source
                       -- NESTED_TUPLE_SOURCE  |LOCAL|
                  }
-          -- EXTERNAL_GROUP_BY[$$1]  |LOCAL|
+          -- EXTERNAL_GROUP_BY[$$1]  |PARTITIONED|
             exchange 
             -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
               data-scan [$$1, $$5]<-[$$1, $$2, $$3, $$4, $$5, $$6, $$7, $$8, $$9, $$10, $$11, $$12, $$13, $$14, $$15, $$16] <- default.lineitem
@@ -29,7 +29,7 @@
                   empty-tuple-source
                   -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
 write [%0->$$36, %0->$$37, %0->$$38, %0->$$39, %0->$$40, %0->$$41]
--- SINK_WRITE  |UNPARTITIONED|
+-- SINK_WRITE  |PARTITIONED|
   project ([$$36, $$37, $$38, $$39, $$40, $$41])
   -- STREAM_PROJECT  |PARTITIONED|
     limit 100
@@ -39,11 +39,11 @@
         exchange 
         -- SORT_MERGE_EXCHANGE [$$40(DESC), $$39(ASC) ]  |PARTITIONED|
           limit 100
-          -- STREAM_LIMIT  |LOCAL|
+          -- STREAM_LIMIT  |PARTITIONED|
             exchange 
-            -- ONE_TO_ONE_EXCHANGE  |LOCAL|
+            -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
               order (DESC, %0->$$40) (ASC, %0->$$39) 
-              -- STABLE_SORT [$$40(DESC), $$39(ASC)]  |LOCAL|
+              -- STABLE_SORT [$$40(DESC), $$39(ASC)]  |PARTITIONED|
                 exchange 
                 -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                   group by ([$$36 := %0->$$44; $$37 := %0->$$45; $$38 := %0->$$46; $$39 := %0->$$47; $$40 := %0->$$48]) decor ([]) {
@@ -61,7 +61,7 @@
                                   nested tuple source
                                   -- NESTED_TUPLE_SOURCE  |LOCAL|
                              }
-                      -- EXTERNAL_GROUP_BY[$$20, $$19, $$27, $$31, $$30]  |LOCAL|
+                      -- EXTERNAL_GROUP_BY[$$20, $$19, $$27, $$31, $$30]  |PARTITIONED|
                         exchange 
                         -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                           project ([$$19, $$20, $$27, $$30, $$31, $$7])
@@ -90,7 +90,7 @@
                                         -- HASH_PARTITION_EXCHANGE [$$1]  |PARTITIONED|
                                           project ([$$1])
                                           -- STREAM_PROJECT  |PARTITIONED|
-                                            select (function-call: algebricks:gt, Args:[%0->$$2, 300])
+                                            select (function-call: algebricks:gt, Args:[%0->$$2, 300.0])
                                             -- STREAM_SELECT  |PARTITIONED|
                                               exchange 
                                               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
@@ -123,4 +123,4 @@
                                             exchange 
                                             -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                                               empty-tuple-source
-                                              -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                                              -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q19_discounted_revenue.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q19_discounted_revenue.plan
index 1827729..9e97b7a 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q19_discounted_revenue.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q19_discounted_revenue.plan
@@ -17,13 +17,13 @@
                     nested tuple source
                     -- NESTED_TUPLE_SOURCE  |LOCAL|
                }
-        -- EXTERNAL_GROUP_BY[]  |LOCAL|
+        -- EXTERNAL_GROUP_BY[]  |PARTITIONED|
           exchange 
           -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
             project ([$$15, $$16])
             -- STREAM_PROJECT  |PARTITIONED|
-              select (function-call: algebricks:or, Args:[function-call: algebricks:or, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:eq, Args:[%0->$$4, Brand#12], function-call: hive:org.apache.hadoop.hive.ql.udf.UDFRegExp, Args:[%0->$$7, SM CASE||SM BOX||SM PACK||SM PKG]], function-call: algebricks:ge, Args:[%0->$$14, 1]], function-call: algebricks:le, Args:[%0->$$14, 11]], function-call: algebricks:ge, Args:[%0->$$6, 1]], function-call: algebricks:le, Args:[%0->$$6, 5]], function-call: hive:org.apache.hadoop.hive.ql.udf.UDFRegExp, Args:[%0->$$24, AIR||AIR REG]], function-call: algebricks:eq, Args:[%0->$$23, DELIVER IN PERSON]], function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:eq, Args:[%0->$$4, Brand#23], function-call: hive:org.apache.hadoop.hive.ql.udf.UDFRegExp, Args:[%0->$$7, MED BAG||MED BOX||MED PKG||MED PACK]], function-call: algebricks:ge, Args:[%0->$$14, 10]], function-call: algebricks:le, Args:[%0->$$14, 20]], function-call: algebricks:ge, Args:[%0->$$6, 1]], function-call: algebricks:le, Args:[%0->$$6, 10]], function-call: hive:org.apache.hadoop.hive.ql.udf.UDFRegExp, Args:[%0->$$24, AIR||AIR REG]], function-call: algebricks:eq, Args:[%0->$$23, DELIVER IN PERSON]]], function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:eq, Args:[%0->$$4, Brand#34], function-call: hive:org.apache.hadoop.hive.ql.udf.UDFRegExp, Args:[%0->$$7, LG CASE||LG BOX||LG PACK||LG PKG]], function-call: algebricks:ge, Args:[%0->$$14, 20]], function-call: algebricks:le, Args:[%0->$$14, 30]], function-call: algebricks:ge, Args:[%0->$$6, 1]], function-call: algebricks:le, Args:[%0->$$6, 15]], function-call: hive:org.apache.hadoop.hive.ql.udf.UDFRegExp, Args:[%0->$$24, AIR||AIR REG]], function-call: algebricks:eq, Args:[%0->$$23, DELIVER IN PERSON]]])
-              -- STREAM_SELECT  |UNPARTITIONED|
+              select (function-call: algebricks:or, Args:[function-call: algebricks:or, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:eq, Args:[%0->$$4, Brand#12], function-call: hive:org.apache.hadoop.hive.ql.udf.UDFRegExp, Args:[%0->$$7, SM CASE||SM BOX||SM PACK||SM PKG]], function-call: algebricks:ge, Args:[%0->$$14, 1.0]], function-call: algebricks:le, Args:[%0->$$14, 11.0]], function-call: algebricks:ge, Args:[%0->$$6, 1]], function-call: algebricks:le, Args:[%0->$$6, 5]], function-call: hive:org.apache.hadoop.hive.ql.udf.UDFRegExp, Args:[%0->$$24, AIR||AIR REG]], function-call: algebricks:eq, Args:[%0->$$23, DELIVER IN PERSON]], function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:eq, Args:[%0->$$4, Brand#23], function-call: hive:org.apache.hadoop.hive.ql.udf.UDFRegExp, Args:[%0->$$7, MED BAG||MED BOX||MED PKG||MED PACK]], function-call: algebricks:ge, Args:[%0->$$14, 10.0]], function-call: algebricks:le, Args:[%0->$$14, 20.0]], function-call: algebricks:ge, Args:[%0->$$6, 1]], function-call: algebricks:le, Args:[%0->$$6, 10]], function-call: hive:org.apache.hadoop.hive.ql.udf.UDFRegExp, Args:[%0->$$24, AIR||AIR REG]], function-call: algebricks:eq, Args:[%0->$$23, DELIVER IN PERSON]]], function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:and, Args:[function-call: algebricks:eq, Args:[%0->$$4, Brand#34], function-call: hive:org.apache.hadoop.hive.ql.udf.UDFRegExp, Args:[%0->$$7, LG CASE||LG BOX||LG PACK||LG PKG]], function-call: algebricks:ge, Args:[%0->$$14, 20.0]], function-call: algebricks:le, Args:[%0->$$14, 30.0]], function-call: algebricks:ge, Args:[%0->$$6, 1]], function-call: algebricks:le, Args:[%0->$$6, 15]], function-call: hive:org.apache.hadoop.hive.ql.udf.UDFRegExp, Args:[%0->$$24, AIR||AIR REG]], function-call: algebricks:eq, Args:[%0->$$23, DELIVER IN PERSON]]])
+              -- STREAM_SELECT  |PARTITIONED|
                 exchange 
                 -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                   join (function-call: algebricks:eq, Args:[%0->$$11, %0->$$1])
@@ -43,4 +43,4 @@
                         exchange 
                         -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                           empty-tuple-source
-                          -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                          -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q1_pricing_summary_report.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q1_pricing_summary_report.plan
index 0e9c90f..de964ac 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q1_pricing_summary_report.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q1_pricing_summary_report.plan
@@ -7,7 +7,7 @@
       exchange 
       -- SORT_MERGE_EXCHANGE [$$17(ASC), $$18(ASC) ]  |PARTITIONED|
         order (ASC, %0->$$17) (ASC, %0->$$18) 
-        -- STABLE_SORT [$$17(ASC), $$18(ASC)]  |LOCAL|
+        -- STABLE_SORT [$$17(ASC), $$18(ASC)]  |PARTITIONED|
           exchange 
           -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
             group by ([$$17 := %0->$$37; $$18 := %0->$$38]) decor ([]) {
@@ -25,7 +25,7 @@
                             nested tuple source
                             -- NESTED_TUPLE_SOURCE  |LOCAL|
                        }
-                -- EXTERNAL_GROUP_BY[$$9, $$10]  |LOCAL|
+                -- EXTERNAL_GROUP_BY[$$9, $$10]  |PARTITIONED|
                   exchange 
                   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                     project ([$$9, $$10, $$5, $$6, $$7, $$8])
@@ -39,4 +39,4 @@
                             exchange 
                             -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                               empty-tuple-source
-                              -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                              -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q20_potential_part_promotion.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q20_potential_part_promotion.plan
index eddfca5..ded599c 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q20_potential_part_promotion.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q20_potential_part_promotion.plan
@@ -5,9 +5,9 @@
     distinct ([%0->$$1])
     -- PRE_SORTED_DISTINCT_BY  |PARTITIONED|
       exchange 
-      -- ONE_TO_ONE_EXCHANGE  |LOCAL|
+      -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
         order (ASC, %0->$$1) 
-        -- STABLE_SORT [$$1(ASC)]  |LOCAL|
+        -- STABLE_SORT [$$1(ASC)]  |PARTITIONED|
           exchange 
           -- HASH_PARTITION_EXCHANGE [$$1]  |PARTITIONED|
             project ([$$1])
@@ -45,12 +45,12 @@
                         nested tuple source
                         -- NESTED_TUPLE_SOURCE  |LOCAL|
                    }
-            -- EXTERNAL_GROUP_BY[$$2, $$3]  |LOCAL|
+            -- EXTERNAL_GROUP_BY[$$2, $$3]  |PARTITIONED|
               exchange 
               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                 project ([$$2, $$3, $$5])
                 -- STREAM_PROJECT  |PARTITIONED|
-                  select (function-call: algebricks:and, Args:[function-call: algebricks:ge, Args:[%0->$$11, 1994-01-01], function-call: algebricks:lt, Args:[%0->$$11, 1995-01-01], function-call: algebricks:ge, Args:[%0->$$11, 1994-01-01], function-call: algebricks:lt, Args:[%0->$$11, 1995-01-01]])
+                  select (function-call: algebricks:and, Args:[function-call: algebricks:ge, Args:[%0->$$11, 1994-01-01], function-call: algebricks:lt, Args:[%0->$$11, 1995-01-01]])
                   -- STREAM_SELECT  |PARTITIONED|
                     exchange 
                     -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
@@ -107,9 +107,9 @@
     distinct ([%0->$$1])
     -- PRE_SORTED_DISTINCT_BY  |PARTITIONED|
       exchange 
-      -- ONE_TO_ONE_EXCHANGE  |LOCAL|
+      -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
         order (ASC, %0->$$1) 
-        -- STABLE_SORT [$$1(ASC)]  |LOCAL|
+        -- STABLE_SORT [$$1(ASC)]  |PARTITIONED|
           exchange 
           -- HASH_PARTITION_EXCHANGE [$$1]  |PARTITIONED|
             project ([$$1])
@@ -129,7 +129,7 @@
   exchange 
   -- SORT_MERGE_EXCHANGE [$$3(ASC) ]  |PARTITIONED|
     order (ASC, %0->$$3) 
-    -- STABLE_SORT [$$3(ASC)]  |LOCAL|
+    -- STABLE_SORT [$$3(ASC)]  |PARTITIONED|
       exchange 
       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
         project ([$$3, $$4])
@@ -175,4 +175,4 @@
                           exchange 
                           -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                             empty-tuple-source
-                            -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                            -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q21_suppliers_who_kept_orders_waiting.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q21_suppliers_who_kept_orders_waiting.plan
index cc47cf3..a22bf53 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q21_suppliers_who_kept_orders_waiting.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q21_suppliers_who_kept_orders_waiting.plan
@@ -23,9 +23,9 @@
                    }
             -- PRE_CLUSTERED_GROUP_BY[$$1, $$3]  |PARTITIONED|
               exchange 
-              -- ONE_TO_ONE_EXCHANGE  |LOCAL|
+              -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                 order (ASC, %0->$$1) (ASC, %0->$$3) 
-                -- STABLE_SORT [$$1(ASC), $$3(ASC)]  |LOCAL|
+                -- STABLE_SORT [$$1(ASC), $$3(ASC)]  |PARTITIONED|
                   exchange 
                   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                     data-scan [$$1, $$3]<-[$$1, $$2, $$3, $$4, $$5, $$6, $$7, $$8, $$9, $$10, $$11, $$12, $$13, $$14, $$15, $$16] <- default.lineitem
@@ -59,9 +59,9 @@
                    }
             -- PRE_CLUSTERED_GROUP_BY[$$1, $$3]  |PARTITIONED|
               exchange 
-              -- ONE_TO_ONE_EXCHANGE  |LOCAL|
+              -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                 order (ASC, %0->$$1) (ASC, %0->$$3) 
-                -- STABLE_SORT [$$1(ASC), $$3(ASC)]  |LOCAL|
+                -- STABLE_SORT [$$1(ASC), $$3(ASC)]  |PARTITIONED|
                   exchange 
                   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                     project ([$$1, $$3])
@@ -89,11 +89,11 @@
           exchange 
           -- SORT_MERGE_EXCHANGE [$$44(DESC), $$43(ASC) ]  |PARTITIONED|
             limit 100
-            -- STREAM_LIMIT  |LOCAL|
+            -- STREAM_LIMIT  |PARTITIONED|
               exchange 
-              -- ONE_TO_ONE_EXCHANGE  |LOCAL|
+              -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                 order (DESC, %0->$$44) (ASC, %0->$$43) 
-                -- STABLE_SORT [$$44(DESC), $$43(ASC)]  |LOCAL|
+                -- STABLE_SORT [$$44(DESC), $$43(ASC)]  |PARTITIONED|
                   exchange 
                   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                     group by ([$$43 := %0->$$48]) decor ([]) {
@@ -111,7 +111,7 @@
                                     nested tuple source
                                     -- NESTED_TUPLE_SOURCE  |LOCAL|
                                }
-                        -- EXTERNAL_GROUP_BY[$$37]  |LOCAL|
+                        -- EXTERNAL_GROUP_BY[$$37]  |PARTITIONED|
                           exchange 
                           -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                             project ([$$37])
@@ -127,7 +127,7 @@
                                       project ([$$37, $$4, $$18])
                                       -- STREAM_PROJECT  |PARTITIONED|
                                         select (function-call: algebricks:or, Args:[function-call: algebricks:gt, Args:[%0->$$5, 1], function-call: algebricks:and, Args:[function-call: algebricks:eq, Args:[%0->$$5, 1], function-call: algebricks:neq, Args:[%0->$$18, %0->$$6]]])
-                                        -- STREAM_SELECT  |UNPARTITIONED|
+                                        -- STREAM_SELECT  |PARTITIONED|
                                           exchange 
                                           -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                                             join (function-call: algebricks:eq, Args:[%0->$$16, %0->$$4])
@@ -150,9 +150,9 @@
                                                             -- HYBRID_HASH_JOIN [$$18][$$36]  |PARTITIONED|
                                                               exchange 
                                                               -- HASH_PARTITION_EXCHANGE [$$18]  |PARTITIONED|
-                                                                project ([$$16, $$18])
+                                                                project ([$$18, $$16])
                                                                 -- STREAM_PROJECT  |PARTITIONED|
-                                                                  select (function-call: algebricks:and, Args:[function-call: algebricks:gt, Args:[%0->$$28, %0->$$27], function-call: algebricks:gt, Args:[%0->$$28, %0->$$27]])
+                                                                  select (function-call: algebricks:gt, Args:[%0->$$28, %0->$$27])
                                                                   -- STREAM_SELECT  |PARTITIONED|
                                                                     exchange 
                                                                     -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
@@ -221,4 +221,4 @@
                                         exchange 
                                         -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                                           empty-tuple-source
-                                          -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                                          -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q22_global_sales_opportunity.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q22_global_sales_opportunity.plan
index 591576b..c5897f7 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q22_global_sales_opportunity.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q22_global_sales_opportunity.plan
@@ -33,7 +33,7 @@
                     nested tuple source
                     -- NESTED_TUPLE_SOURCE  |LOCAL|
                }
-        -- EXTERNAL_GROUP_BY[]  |LOCAL|
+        -- EXTERNAL_GROUP_BY[]  |PARTITIONED|
           exchange 
           -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
             select (function-call: algebricks:gt, Args:[%0->$$1, 0.0])
@@ -53,9 +53,9 @@
     distinct ([%0->$$2])
     -- PRE_SORTED_DISTINCT_BY  |PARTITIONED|
       exchange 
-      -- ONE_TO_ONE_EXCHANGE  |LOCAL|
+      -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
         order (ASC, %0->$$2) 
-        -- STABLE_SORT [$$2(ASC)]  |LOCAL|
+        -- STABLE_SORT [$$2(ASC)]  |PARTITIONED|
           exchange 
           -- HASH_PARTITION_EXCHANGE [$$2]  |PARTITIONED|
             data-scan [$$2]<-[$$1, $$2, $$3, $$4, $$5, $$6, $$7, $$8, $$9] <- default.orders
@@ -73,7 +73,7 @@
       exchange 
       -- SORT_MERGE_EXCHANGE [$$6(ASC) ]  |PARTITIONED|
         order (ASC, %0->$$6) 
-        -- STABLE_SORT [$$6(ASC)]  |LOCAL|
+        -- STABLE_SORT [$$6(ASC)]  |PARTITIONED|
           exchange 
           -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
             group by ([$$6 := %0->$$13]) decor ([]) {
@@ -91,7 +91,7 @@
                             nested tuple source
                             -- NESTED_TUPLE_SOURCE  |LOCAL|
                        }
-                -- EXTERNAL_GROUP_BY[$$5]  |LOCAL|
+                -- EXTERNAL_GROUP_BY[$$5]  |PARTITIONED|
                   exchange 
                   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                     project ([$$5, $$3])
@@ -133,4 +133,4 @@
                               exchange 
                               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                                 empty-tuple-source
-                                -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                                -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q2_minimum_cost_supplier.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q2_minimum_cost_supplier.plan
index 151f34d..6138f7a 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q2_minimum_cost_supplier.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q2_minimum_cost_supplier.plan
@@ -10,7 +10,7 @@
         -- HASH_PARTITION_EXCHANGE [$$1]  |PARTITIONED|
           project ([$$1, $$3])
           -- STREAM_PROJECT  |PARTITIONED|
-            select (function-call: algebricks:and, Args:[function-call: hive:org.apache.hadoop.hive.ql.udf.UDFLike, Args:[%0->$$5, %BRASS], function-call: algebricks:eq, Args:[%0->$$6, 15], function-call: hive:org.apache.hadoop.hive.ql.udf.UDFLike, Args:[%0->$$5, %BRASS]])
+            select (function-call: algebricks:and, Args:[function-call: algebricks:eq, Args:[%0->$$6, 15], function-call: hive:org.apache.hadoop.hive.ql.udf.UDFLike, Args:[%0->$$5, %BRASS]])
             -- STREAM_SELECT  |PARTITIONED|
               exchange 
               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
@@ -103,11 +103,11 @@
                       nested tuple source
                       -- NESTED_TUPLE_SOURCE  |LOCAL|
                  }
-          -- PRE_CLUSTERED_GROUP_BY[$$4]  |LOCAL|
+          -- PRE_CLUSTERED_GROUP_BY[$$4]  |PARTITIONED|
             exchange 
-            -- ONE_TO_ONE_EXCHANGE  |LOCAL|
+            -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
               order (ASC, %0->$$4) 
-              -- STABLE_SORT [$$4(ASC)]  |LOCAL|
+              -- STABLE_SORT [$$4(ASC)]  |PARTITIONED|
                 exchange 
                 -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                   data-scan [$$4, $$5]<-[$$1, $$2, $$3, $$4, $$5, $$6, $$7, $$8, $$9] <- default.q2_minimum_cost_supplier_tmp1
@@ -125,11 +125,11 @@
       exchange 
       -- SORT_MERGE_EXCHANGE [$$3(DESC), $$5(ASC), $$4(ASC), $$6(ASC) ]  |PARTITIONED|
         limit 100
-        -- STREAM_LIMIT  |LOCAL|
+        -- STREAM_LIMIT  |PARTITIONED|
           exchange 
-          -- ONE_TO_ONE_EXCHANGE  |LOCAL|
+          -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
             order (DESC, %0->$$3) (ASC, %0->$$5) (ASC, %0->$$4) (ASC, %0->$$6) 
-            -- STABLE_SORT [$$3(DESC), $$5(ASC), $$4(ASC), $$6(ASC)]  |LOCAL|
+            -- STABLE_SORT [$$3(DESC), $$5(ASC), $$4(ASC), $$6(ASC)]  |PARTITIONED|
               exchange 
               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                 project ([$$3, $$4, $$5, $$6, $$8, $$9, $$10, $$11])
@@ -153,4 +153,4 @@
                           exchange 
                           -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                             empty-tuple-source
-                            -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                            -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q3_shipping_priority.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q3_shipping_priority.plan
index a1b8e42..31c4210 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q3_shipping_priority.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q3_shipping_priority.plan
@@ -7,11 +7,11 @@
       exchange 
       -- SORT_MERGE_EXCHANGE [$$34(DESC) ]  |PARTITIONED|
         limit 10
-        -- STREAM_LIMIT  |LOCAL|
+        -- STREAM_LIMIT  |PARTITIONED|
           exchange 
-          -- ONE_TO_ONE_EXCHANGE  |LOCAL|
+          -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
             order (DESC, %0->$$34) 
-            -- STABLE_SORT [$$34(DESC)]  |LOCAL|
+            -- STABLE_SORT [$$34(DESC)]  |PARTITIONED|
               exchange 
               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                 project ([$$1, $$34, $$29, $$32])
@@ -67,4 +67,4 @@
                                             exchange 
                                             -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                                               empty-tuple-source
-                                              -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                                              -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q4_order_priority.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q4_order_priority.plan
index 435fd7c..be5a66a 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q4_order_priority.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q4_order_priority.plan
@@ -5,9 +5,9 @@
     distinct ([%0->$$1])
     -- PRE_SORTED_DISTINCT_BY  |PARTITIONED|
       exchange 
-      -- ONE_TO_ONE_EXCHANGE  |LOCAL|
+      -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
         order (ASC, %0->$$1) 
-        -- STABLE_SORT [$$1(ASC)]  |LOCAL|
+        -- STABLE_SORT [$$1(ASC)]  |PARTITIONED|
           exchange 
           -- HASH_PARTITION_EXCHANGE [$$1]  |PARTITIONED|
             project ([$$1])
@@ -31,7 +31,7 @@
       exchange 
       -- SORT_MERGE_EXCHANGE [$$11(ASC) ]  |PARTITIONED|
         order (ASC, %0->$$11) 
-        -- STABLE_SORT [$$11(ASC)]  |LOCAL|
+        -- STABLE_SORT [$$11(ASC)]  |PARTITIONED|
           exchange 
           -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
             group by ([$$11 := %0->$$16]) decor ([]) {
@@ -49,7 +49,7 @@
                             nested tuple source
                             -- NESTED_TUPLE_SOURCE  |LOCAL|
                        }
-                -- EXTERNAL_GROUP_BY[$$7]  |LOCAL|
+                -- EXTERNAL_GROUP_BY[$$7]  |PARTITIONED|
                   exchange 
                   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                     project ([$$7])
@@ -70,7 +70,7 @@
                           -- HASH_PARTITION_EXCHANGE [$$2]  |PARTITIONED|
                             project ([$$2, $$7])
                             -- STREAM_PROJECT  |PARTITIONED|
-                              select (function-call: algebricks:and, Args:[function-call: algebricks:lt, Args:[%0->$$6, 1993-10-01], function-call: algebricks:ge, Args:[%0->$$6, 1993-07-01], function-call: algebricks:lt, Args:[%0->$$6, 1993-10-01]])
+                              select (function-call: algebricks:and, Args:[function-call: algebricks:ge, Args:[%0->$$6, 1993-07-01], function-call: algebricks:lt, Args:[%0->$$6, 1993-10-01]])
                               -- STREAM_SELECT  |PARTITIONED|
                                 exchange 
                                 -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
@@ -79,4 +79,4 @@
                                     exchange 
                                     -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                                       empty-tuple-source
-                                      -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                                      -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q5_local_supplier_volume.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q5_local_supplier_volume.plan
index 177d24c..383e550 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q5_local_supplier_volume.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q5_local_supplier_volume.plan
@@ -5,7 +5,7 @@
     exchange 
     -- SORT_MERGE_EXCHANGE [$$49(DESC) ]  |PARTITIONED|
       order (DESC, %0->$$49) 
-      -- STABLE_SORT [$$49(DESC)]  |LOCAL|
+      -- STABLE_SORT [$$49(DESC)]  |PARTITIONED|
         exchange 
         -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
           group by ([$$48 := %0->$$52]) decor ([]) {
@@ -23,7 +23,7 @@
                           nested tuple source
                           -- NESTED_TUPLE_SOURCE  |LOCAL|
                      }
-              -- EXTERNAL_GROUP_BY[$$42]  |LOCAL|
+              -- EXTERNAL_GROUP_BY[$$42]  |PARTITIONED|
                 exchange 
                 -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                   project ([$$42, $$23, $$24])
@@ -106,7 +106,7 @@
                                 -- HASH_PARTITION_EXCHANGE [$$9]  |PARTITIONED|
                                   project ([$$9, $$10])
                                   -- STREAM_PROJECT  |PARTITIONED|
-                                    select (function-call: algebricks:and, Args:[function-call: algebricks:lt, Args:[%0->$$13, 1995-01-01], function-call: algebricks:ge, Args:[%0->$$13, 1994-01-01], function-call: algebricks:lt, Args:[%0->$$13, 1995-01-01]])
+                                    select (function-call: algebricks:and, Args:[function-call: algebricks:ge, Args:[%0->$$13, 1994-01-01], function-call: algebricks:lt, Args:[%0->$$13, 1995-01-01]])
                                     -- STREAM_SELECT  |PARTITIONED|
                                       exchange 
                                       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
@@ -123,4 +123,4 @@
                             exchange 
                             -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                               empty-tuple-source
-                              -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                              -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q6_forecast_revenue_change.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q6_forecast_revenue_change.plan
index cd9ffcd..aac9a5b 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q6_forecast_revenue_change.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q6_forecast_revenue_change.plan
@@ -17,12 +17,12 @@
                     nested tuple source
                     -- NESTED_TUPLE_SOURCE  |LOCAL|
                }
-        -- EXTERNAL_GROUP_BY[]  |LOCAL|
+        -- EXTERNAL_GROUP_BY[]  |PARTITIONED|
           exchange 
           -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
             project ([$$6, $$7])
             -- STREAM_PROJECT  |PARTITIONED|
-              select (function-call: algebricks:and, Args:[function-call: algebricks:ge, Args:[%0->$$11, 1994-01-01], function-call: algebricks:lt, Args:[%0->$$11, 1995-01-01], function-call: algebricks:ge, Args:[%0->$$7, 0.05], function-call: algebricks:le, Args:[%0->$$7, 0.07], function-call: algebricks:lt, Args:[%0->$$5, 24], function-call: algebricks:ge, Args:[%0->$$11, 1994-01-01], function-call: algebricks:lt, Args:[%0->$$11, 1995-01-01], function-call: algebricks:ge, Args:[%0->$$7, 0.05], function-call: algebricks:le, Args:[%0->$$7, 0.07], function-call: algebricks:lt, Args:[%0->$$5, 24]])
+              select (function-call: algebricks:and, Args:[function-call: algebricks:ge, Args:[%0->$$11, 1994-01-01], function-call: algebricks:lt, Args:[%0->$$11, 1995-01-01], function-call: algebricks:ge, Args:[%0->$$7, 0.05], function-call: algebricks:le, Args:[%0->$$7, 0.07], function-call: algebricks:lt, Args:[%0->$$5, 24.0]])
               -- STREAM_SELECT  |PARTITIONED|
                 exchange 
                 -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
@@ -31,4 +31,4 @@
                     exchange 
                     -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                       empty-tuple-source
-                      -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                      -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q7_volume_shipping.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q7_volume_shipping.plan
index 39f8301..c1d5b26 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q7_volume_shipping.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q7_volume_shipping.plan
@@ -5,9 +5,9 @@
     union ($$6, $$10, $$17) ($$2, $$14, $$18) ($$5, $$9, $$19) ($$1, $$13, $$20)
     -- UNION_ALL  |PARTITIONED|
       exchange 
-      -- ONE_TO_ONE_EXCHANGE  |UNPARTITIONED|
+      -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
         project ([$$6, $$2, $$5, $$1])
-        -- STREAM_PROJECT  |UNPARTITIONED|
+        -- STREAM_PROJECT  |PARTITIONED|
           exchange 
           -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
             join (true)
@@ -31,9 +31,9 @@
                   select (function-call: algebricks:eq, Args:[%0->$$6, FRANCE])
                   -- STREAM_SELECT  |PARTITIONED|
                     project ([$$5, $$6])
-                    -- STREAM_PROJECT  |UNPARTITIONED|
+                    -- STREAM_PROJECT  |PARTITIONED|
                       assign [$$5, $$6] <- [%0->$$9, %0->$$10]
-                      -- ASSIGN  |UNPARTITIONED|
+                      -- ASSIGN  |PARTITIONED|
                         exchange 
                         -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                           replicate 
@@ -47,9 +47,9 @@
                                   empty-tuple-source
                                   -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
       exchange 
-      -- ONE_TO_ONE_EXCHANGE  |UNPARTITIONED|
+      -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
         project ([$$10, $$14, $$9, $$13])
-        -- STREAM_PROJECT  |UNPARTITIONED|
+        -- STREAM_PROJECT  |PARTITIONED|
           exchange 
           -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
             join (true)
@@ -91,7 +91,7 @@
     exchange 
     -- SORT_MERGE_EXCHANGE [$$47(ASC), $$48(ASC), $$49(ASC) ]  |PARTITIONED|
       order (ASC, %0->$$47) (ASC, %0->$$48) (ASC, %0->$$49) 
-      -- STABLE_SORT [$$47(ASC), $$48(ASC), $$49(ASC)]  |LOCAL|
+      -- STABLE_SORT [$$47(ASC), $$48(ASC), $$49(ASC)]  |PARTITIONED|
         exchange 
         -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
           group by ([$$47 := %0->$$53; $$48 := %0->$$54; $$49 := %0->$$55]) decor ([]) {
@@ -109,7 +109,7 @@
                           nested tuple source
                           -- NESTED_TUPLE_SOURCE  |LOCAL|
                      }
-              -- EXTERNAL_GROUP_BY[$$1, $$2, $$45]  |LOCAL|
+              -- EXTERNAL_GROUP_BY[$$1, $$2, $$45]  |PARTITIONED|
                 exchange 
                 -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                   project ([$$1, $$2, $$45, $$46])
@@ -148,7 +148,7 @@
                                                   -- HYBRID_HASH_JOIN [$$20][$$36]  |PARTITIONED|
                                                     exchange 
                                                     -- HASH_PARTITION_EXCHANGE [$$20]  |PARTITIONED|
-                                                      select (function-call: algebricks:and, Args:[function-call: algebricks:le, Args:[%0->$$30, 1996-12-31], function-call: algebricks:ge, Args:[%0->$$30, 1995-01-01], function-call: algebricks:le, Args:[%0->$$30, 1996-12-31]])
+                                                      select (function-call: algebricks:and, Args:[function-call: algebricks:ge, Args:[%0->$$30, 1995-01-01], function-call: algebricks:le, Args:[%0->$$30, 1996-12-31]])
                                                       -- STREAM_SELECT  |PARTITIONED|
                                                         exchange 
                                                         -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
@@ -189,4 +189,4 @@
                                 exchange 
                                 -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                                   empty-tuple-source
-                                  -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                                  -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q8_national_market_share.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q8_national_market_share.plan
index b807a24..b9916e2 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q8_national_market_share.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q8_national_market_share.plan
@@ -3,7 +3,7 @@
   exchange 
   -- SORT_MERGE_EXCHANGE [$$63(ASC) ]  |PARTITIONED|
     order (ASC, %0->$$63) 
-    -- STABLE_SORT [$$63(ASC)]  |LOCAL|
+    -- STABLE_SORT [$$63(ASC)]  |PARTITIONED|
       exchange 
       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
         project ([$$63, $$66])
@@ -27,7 +27,7 @@
                               nested tuple source
                               -- NESTED_TUPLE_SOURCE  |LOCAL|
                          }
-                  -- EXTERNAL_GROUP_BY[$$61]  |LOCAL|
+                  -- EXTERNAL_GROUP_BY[$$61]  |PARTITIONED|
                     exchange 
                     -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                       project ([$$61, $$62, $$2])
@@ -138,7 +138,7 @@
                                                                 -- HASH_PARTITION_EXCHANGE [$$38]  |PARTITIONED|
                                                                   project ([$$38, $$37, $$41])
                                                                   -- STREAM_PROJECT  |PARTITIONED|
-                                                                    select (function-call: algebricks:and, Args:[function-call: algebricks:lt, Args:[%0->$$41, 1996-12-31], function-call: algebricks:ge, Args:[%0->$$41, 1995-01-01]])
+                                                                    select (function-call: algebricks:and, Args:[function-call: algebricks:ge, Args:[%0->$$41, 1995-01-01], function-call: algebricks:lt, Args:[%0->$$41, 1996-12-31]])
                                                                     -- STREAM_SELECT  |PARTITIONED|
                                                                       exchange 
                                                                       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
@@ -175,7 +175,7 @@
                                   project ([$$1, $$2])
                                   -- STREAM_PROJECT  |PARTITIONED|
                                     assign [$$1, $$2, $$3, $$4] <- [%0->$$54, %0->$$55, %0->$$56, %0->$$57]
-                                    -- ASSIGN  |UNPARTITIONED|
+                                    -- ASSIGN  |PARTITIONED|
                                       exchange 
                                       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                                         replicate 
@@ -187,4 +187,4 @@
                                               exchange 
                                               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                                                 empty-tuple-source
-                                                -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                                                -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q9_product_type_profit.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q9_product_type_profit.plan
index f57f4a3..ecf4acb 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q9_product_type_profit.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/q9_product_type_profit.plan
@@ -5,7 +5,7 @@
     exchange 
     -- SORT_MERGE_EXCHANGE [$$53(ASC), $$54(DESC) ]  |PARTITIONED|
       order (ASC, %0->$$53) (DESC, %0->$$54) 
-      -- STABLE_SORT [$$53(ASC), $$54(DESC)]  |LOCAL|
+      -- STABLE_SORT [$$53(ASC), $$54(DESC)]  |PARTITIONED|
         exchange 
         -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
           group by ([$$53 := %0->$$58; $$54 := %0->$$59]) decor ([]) {
@@ -23,7 +23,7 @@
                           nested tuple source
                           -- NESTED_TUPLE_SOURCE  |LOCAL|
                      }
-              -- EXTERNAL_GROUP_BY[$$48, $$51]  |LOCAL|
+              -- EXTERNAL_GROUP_BY[$$48, $$51]  |PARTITIONED|
                 exchange 
                 -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                   project ([$$48, $$51, $$52])
@@ -121,4 +121,4 @@
                                 exchange 
                                 -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                                   empty-tuple-source
-                                  -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                                  -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/u1_group_by.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/u1_group_by.plan
index 188aa6d..bec1353 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/u1_group_by.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/u1_group_by.plan
@@ -19,7 +19,7 @@
                       nested tuple source
                       -- NESTED_TUPLE_SOURCE  |LOCAL|
                  }
-          -- EXTERNAL_GROUP_BY[$$9]  |LOCAL|
+          -- EXTERNAL_GROUP_BY[$$9]  |PARTITIONED|
             exchange 
             -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
               project ([$$9, $$5, $$6, $$7, $$8])
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/u5_lateral_view.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/u5_lateral_view.plan
index 48e624e..2cbea4a 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/u5_lateral_view.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/u5_lateral_view.plan
@@ -6,7 +6,7 @@
     -- UNNEST  |PARTITIONED|
       exchange 
       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-        data-scan [$$1, $$2, $$3]<-[$$1, $$2, $$3, $$4, $$5, $$6, $$7] <- default.supplier
+        data-scan [$$2, $$3, $$1]<-[$$1, $$2, $$3, $$4, $$5, $$6, $$7] <- default.supplier
         -- DATASOURCE_SCAN  |PARTITIONED|
           exchange 
           -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/u6_limit.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/u6_limit.plan
index b5ed12f..6a0b125 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/u6_limit.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/u6_limit.plan
@@ -7,14 +7,14 @@
       exchange 
       -- SORT_MERGE_EXCHANGE [$$4(ASC) ]  |PARTITIONED|
         limit 4
-        -- STREAM_LIMIT  |LOCAL|
+        -- STREAM_LIMIT  |PARTITIONED|
           exchange 
-          -- ONE_TO_ONE_EXCHANGE  |LOCAL|
+          -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
             order (ASC, %0->$$4) 
-            -- STABLE_SORT [$$4(ASC)]  |LOCAL|
+            -- STABLE_SORT [$$4(ASC)]  |PARTITIONED|
               exchange 
               -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                select (function-call: algebricks:lt, Args:[%0->$$4, 10000])
+                select (function-call: algebricks:lt, Args:[%0->$$4, 10000.0])
                 -- STREAM_SELECT  |PARTITIONED|
                   exchange 
                   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/u7_multi_join.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/u7_multi_join.plan
index ab55181..b5f1dc2 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/u7_multi_join.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/u7_multi_join.plan
@@ -16,37 +16,35 @@
               -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
         exchange 
         -- HASH_PARTITION_EXCHANGE [$$25]  |PARTITIONED|
-          project ([$$32, $$25, $$29, $$28])
+          project ([$$25, $$28, $$29, $$32])
           -- STREAM_PROJECT  |PARTITIONED|
-            project ([$$25, $$17, $$28, $$29, $$32])
-            -- STREAM_PROJECT  |PARTITIONED|
-              exchange 
-              -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                join (function-call: algebricks:eq, Args:[%0->$$26, %0->$$17])
-                -- HYBRID_HASH_JOIN [$$26][$$17]  |PARTITIONED|
-                  exchange 
-                  -- HASH_PARTITION_EXCHANGE [$$26]  |PARTITIONED|
-                    select (function-call: algebricks:and, Args:[function-call: algebricks:lt, Args:[%0->$$28, 30000], function-call: algebricks:lt, Args:[%0->$$28, 30000]])
+            exchange 
+            -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+              join (function-call: algebricks:eq, Args:[%0->$$26, %0->$$17])
+              -- HYBRID_HASH_JOIN [$$26][$$17]  |PARTITIONED|
+                exchange 
+                -- HASH_PARTITION_EXCHANGE [$$26]  |PARTITIONED|
+                  select (function-call: algebricks:and, Args:[function-call: algebricks:lt, Args:[%0->$$28, 30000.0], function-call: algebricks:lt, Args:[%0->$$26, 5]])
+                  -- STREAM_SELECT  |PARTITIONED|
+                    exchange 
+                    -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                      data-scan [$$32, $$25, $$26, $$29, $$28]<-[$$25, $$26, $$27, $$28, $$29, $$30, $$31, $$32, $$33] <- default.orders
+                      -- DATASOURCE_SCAN  |PARTITIONED|
+                        exchange 
+                        -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                          empty-tuple-source
+                          -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                exchange 
+                -- HASH_PARTITION_EXCHANGE [$$17]  |PARTITIONED|
+                  project ([$$17])
+                  -- STREAM_PROJECT  |PARTITIONED|
+                    select (function-call: algebricks:lt, Args:[%0->$$17, 5])
                     -- STREAM_SELECT  |PARTITIONED|
                       exchange 
                       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                        data-scan [$$32, $$25, $$26, $$29, $$28]<-[$$25, $$26, $$27, $$28, $$29, $$30, $$31, $$32, $$33] <- default.orders
+                        data-scan [$$17]<-[$$17, $$18, $$19, $$20, $$21, $$22, $$23, $$24] <- default.customer
                         -- DATASOURCE_SCAN  |PARTITIONED|
                           exchange 
                           -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
                             empty-tuple-source
-                            -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
-                  exchange 
-                  -- HASH_PARTITION_EXCHANGE [$$17]  |PARTITIONED|
-                    project ([$$17])
-                    -- STREAM_PROJECT  |PARTITIONED|
-                      select (function-call: algebricks:and, Args:[function-call: algebricks:lt, Args:[%0->$$17, 5], function-call: algebricks:lt, Args:[%0->$$17, 5]])
-                      -- STREAM_SELECT  |PARTITIONED|
-                        exchange 
-                        -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                          data-scan [$$17]<-[$$17, $$18, $$19, $$20, $$21, $$22, $$23, $$24] <- default.customer
-                          -- DATASOURCE_SCAN  |PARTITIONED|
-                            exchange 
-                            -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                              empty-tuple-source
-                              -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+                            -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/u9_order_by.plan b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/u9_order_by.plan
index 7370fcf..344898d 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/u9_order_by.plan
+++ b/hivesterix/hivesterix-dist/src/test/resources/optimizerts/results/u9_order_by.plan
@@ -3,7 +3,7 @@
   exchange 
   -- SORT_MERGE_EXCHANGE [$$2(ASC) ]  |PARTITIONED|
     order (ASC, %0->$$2) 
-    -- STABLE_SORT [$$2(ASC)]  |LOCAL|
+    -- STABLE_SORT [$$2(ASC)]  |PARTITIONED|
       exchange 
       -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
         select (function-call: algebricks:lt, Args:[function-call: hive:org.apache.hadoop.hive.ql.udf.UDFOPMultiply, Args:[%0->$$1, 2], 20])
diff --git a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/hive/conf/hive-default.xml b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/hive/conf/hive-default.xml
index a4ee677..49cdedf 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/hive/conf/hive-default.xml
+++ b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/hive/conf/hive-default.xml
@@ -1,22 +1,66 @@
 <?xml version="1.0"?>
-<!--
- ! Copyright 2009-2013 by The Regents of the University of California
- ! Licensed under the Apache License, Version 2.0 (the "License");
- ! you may not use this file except in compliance with the License.
- ! you may obtain a copy of the License from
- ! 
- !     http://www.apache.org/licenses/LICENSE-2.0
- ! 
- ! Unless required by applicable law or agreed to in writing, software
- ! distributed under the License is distributed on an "AS IS" BASIS,
- ! WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- ! See the License for the specific language governing permissions and
- ! limitations under the License.
- !-->
+<!-- ! Copyright 2009-2013 by The Regents of the University of California 
+	! Licensed under the Apache License, Version 2.0 (the "License"); ! you may 
+	not use this file except in compliance with the License. ! you may obtain 
+	a copy of the License from ! ! http://www.apache.org/licenses/LICENSE-2.0 
+	! ! Unless required by applicable law or agreed to in writing, software ! 
+	distributed under the License is distributed on an "AS IS" BASIS, ! WITHOUT 
+	WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. ! See the 
+	License for the specific language governing permissions and ! limitations 
+	under the License. ! -->
 <?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
 
 <configuration>
 
+	<!-- Hivesterix Execution Parameters -->
+	<property>
+		<name>hive.hyracks.connectorpolicy</name>
+		<value>PIPELINING</value>
+	</property>
+
+	<property>
+		<name>hive.hyracks.parrallelism</name>
+		<value>4</value>
+	</property>
+
+	<property>
+		<name>hive.algebricks.groupby.external</name>
+		<value>true</value>
+	</property>
+
+	<property>
+		<name>hive.algebricks.groupby.external.memory</name>
+		<value>3072</value>
+	</property>
+
+	<property>
+		<name>hive.algebricks.sort.memory</name>
+		<value>3072</value>
+	</property>
+
+	<property>
+		<name>hive.algebricks.framesize</name>
+		<value>768</value>
+	</property>
+
+	<property>
+		<name>hive.auto.convert.join</name>
+		<value>false</value>
+	</property>
+
+	<property>
+		<name>hive.auto.convert.join.noconditionaltask</name>
+		<value>false</value>
+		<description>Whether Hive enable the optimization about converting
+			common join into mapjoin based on the input file
+			size. If this paramater is on, and the sum of size for n-1 of the
+			tables/partitions for a n-way join is smaller than the
+			specified size, the join is directly converted to a mapjoin (there is no
+			conditional task).
+		</description>
+	</property>
+
+
 	<!-- Hive Configuration can either be stored in this file or in the hadoop 
 		configuration files -->
 	<!-- that are implied by Hadoop setup variables. -->
@@ -42,52 +86,6 @@
 	</property>
 
 	<property>
-		<name>hive.hyracks.connectorpolicy</name>
-		<value>SEND_SIDE_MAT_PIPELINING</value>
-	</property>
-
-	<property>
-		<name>hive.hyracks.host</name>
-		<value>127.0.0.1</value>
-	</property>
-
-	<property>
-		<name>hive.hyracks.port</name>
-		<value>13099</value>
-	</property>
-
-	<property>
-		<name>hive.hyracks.app</name>
-		<value>hivesterix</value>
-	</property>
-
-
-	<property>
-		<name>hive.hyracks.parrallelism</name>
-		<value>2</value>
-	</property>
-
-	<property>
-		<name>hive.algebricks.groupby.external</name>
-		<value>true</value>
-	</property>
-
-	<property>
-		<name>hive.algebricks.groupby.external.memory</name>
-		<value>3072</value>
-	</property>
-
-	<property>
-		<name>hive.algebricks.sort.memory</name>
-		<value>3072</value>
-	</property>
-
-	<property>
-		<name>hive.algebricks.framesize</name>
-		<value>768</value>
-	</property>
-
-	<property>
 		<name>hive.exec.reducers.bytes.per.reducer</name>
 		<value>1000000000</value>
 		<description>size per reducer.The default is 1G, i.e if the input size
diff --git a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/logging.properties b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/logging.properties
index a7d8d9c..f886a44 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/logging.properties
+++ b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/logging.properties
@@ -43,7 +43,7 @@
 # Note that the ConsoleHandler also has a separate level
 # setting to limit messages printed to the console.
 
-.level= WARNING
+.level= INFO
 # .level= INFO
 # .level= FINE
 # .level = FINEST
diff --git a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q10_returned_item.hive b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q10_returned_item.hive
index 3f1214a..bb07665 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q10_returned_item.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q10_returned_item.hive
@@ -13,9 +13,6 @@
 -- create the result table
 create table q10_returned_item (c_custkey int, c_name string, revenue double, c_acctbal string, n_name string, c_address string, c_phone string, c_comment string);
 
-set mapred.min.split.size=536870912;
-set hive.exec.reducers.bytes.per.reducer=1024000000;
-
 -- the query
 insert overwrite table q10_returned_item
 select 
diff --git a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q12_shipping.hive b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q12_shipping.hive
index 062f7b9..8546365 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q12_shipping.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q12_shipping.hive
@@ -9,9 +9,6 @@
 -- create the result table
 create table q12_shipping(l_shipmode string, high_line_count double, low_line_count double);
 
-set mapred.min.split.size=536870912;
-set hive.exec.reducers.bytes.per.reducer=1225000000;
-
 -- the query
 insert overwrite table q12_shipping
 select 
diff --git a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q14_promotion_effect.hive b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q14_promotion_effect.hive
index 988f400..4644d23 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q14_promotion_effect.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q14_promotion_effect.hive
@@ -9,9 +9,6 @@
 -- create the result table
 create table q14_promotion_effect(promo_revenue double);
 
-set mapred.min.split.size=536870912;
-set hive.exec.reducers.bytes.per.reducer=1040000000;
-
 -- the query
 insert overwrite table q14_promotion_effect
 select 
diff --git a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q15_top_supplier.hive b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q15_top_supplier.hive
index 04064ed..8fa333e 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q15_top_supplier.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q15_top_supplier.hive
@@ -14,8 +14,6 @@
 create table q15_top_supplier(s_suppkey int, s_name string, s_address string, s_phone string, total_revenue double);
 
 
-set mapred.min.split.size=536870912;
-
 -- the query
 insert overwrite table revenue
 select 
diff --git a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q18_large_volume_customer.hive b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q18_large_volume_customer.hive
index ac2902c..d1eaacc 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q18_large_volume_customer.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q18_large_volume_customer.hive
@@ -13,9 +13,6 @@
 create table q18_tmp(l_orderkey int, t_sum_quantity double);
 create table q18_large_volume_customer(c_name string, c_custkey int, o_orderkey int, o_orderdate string, o_totalprice double, sum_quantity double);
 
-set mapred.min.split.size=268435456;
-set hive.exec.reducers.bytes.per.reducer=1164000000;
-
 -- the query
 insert overwrite table q18_tmp
 select 
diff --git a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q19_discounted_revenue.hive b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q19_discounted_revenue.hive
index 2002e1e..6badfcf 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q19_discounted_revenue.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q19_discounted_revenue.hive
@@ -9,9 +9,6 @@
 -- create the result table
 create table q19_discounted_revenue(revenue double);
 
-set mapred.min.split.size=268435456;
-set hive.exec.reducers.bytes.per.reducer=1040000000;
-
 -- the query
 insert overwrite table q19_discounted_revenue
 select
diff --git a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q1_pricing_summary_report.hive b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q1_pricing_summary_report.hive
index a002068..af64a4f 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q1_pricing_summary_report.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q1_pricing_summary_report.hive
@@ -7,8 +7,6 @@
 -- create the target table
 CREATE TABLE q1_pricing_summary_report ( L_RETURNFLAG STRING, L_LINESTATUS STRING, SUM_QTY DOUBLE, SUM_BASE_PRICE DOUBLE, SUM_DISC_PRICE DOUBLE, SUM_CHARGE DOUBLE, AVE_QTY DOUBLE, AVE_PRICE DOUBLE, AVE_DISC DOUBLE, COUNT_ORDER INT);
 
-set mapred.min.split.size=536870912;
-
 -- the query
 INSERT OVERWRITE TABLE q1_pricing_summary_report 
 SELECT 
diff --git a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q20_potential_part_promotion.hive b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q20_potential_part_promotion.hive
index 2bb90ea..32181bf 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q20_potential_part_promotion.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q20_potential_part_promotion.hive
@@ -23,8 +23,6 @@
 create table q20_tmp4(ps_suppkey int);
 create table q20_potential_part_promotion(s_name string, s_address string);
 
-set mapred.min.split.size=536870912;
-
 -- the query
 insert overwrite table q20_tmp1
 select distinct p_partkey
diff --git a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q3_shipping_priority.hive b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q3_shipping_priority.hive
index 0049eb3..67f6dc4 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q3_shipping_priority.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q3_shipping_priority.hive
@@ -11,9 +11,6 @@
 -- create the target table
 create table q3_shipping_priority (l_orderkey int, revenue double, o_orderdate string, o_shippriority int);
 
-set mapred.min.split.size=536870912;
-set hive.exec.reducers.bytes.per.reducer=1024000000;
-
 -- the query
 Insert overwrite table q3_shipping_priority 
 select 
diff --git a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q4_order_priority.hive b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q4_order_priority.hive
index aa828e9..efbcff2 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q4_order_priority.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q4_order_priority.hive
@@ -11,7 +11,6 @@
 CREATE TABLE q4_order_priority_tmp (O_ORDERKEY INT);
 CREATE TABLE q4_order_priority (O_ORDERPRIORITY STRING, ORDER_COUNT INT);
 
-set mapred.min.split.size=536870912;
 -- the query
 INSERT OVERWRITE TABLE q4_order_priority_tmp 
 select 
diff --git a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q5_local_supplier_volume.hive b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q5_local_supplier_volume.hive
index 9af2dd2..838a1e8 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q5_local_supplier_volume.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q5_local_supplier_volume.hive
@@ -17,7 +17,6 @@
 -- create the target table
 create table q5_local_supplier_volume (N_NAME STRING, REVENUE DOUBLE);
 
-set mapred.min.split.size=536870912;
 
 -- the query
 insert overwrite table q5_local_supplier_volume 
diff --git a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q7_volume_shipping.hive b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q7_volume_shipping.hive
index 2678f80..12ae8ae 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q7_volume_shipping.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q7_volume_shipping.hive
@@ -17,9 +17,6 @@
 create table q7_volume_shipping (supp_nation string, cust_nation string, l_year int, revenue double);
 create table q7_volume_shipping_tmp(supp_nation string, cust_nation string, s_nationkey int, c_nationkey int);
 
-set mapred.min.split.size=536870912;
-set hive.exec.reducers.bytes.per.reducer=1225000000;
-
 -- the query
 insert overwrite table q7_volume_shipping_tmp
 select 
diff --git a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q9_product_type_profit.hive b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q9_product_type_profit.hive
index 2e5b4a1..c491997 100644
--- a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q9_product_type_profit.hive
+++ b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/q9_product_type_profit.hive
@@ -17,9 +17,6 @@
 -- create the result table
 create table q9_product_type_profit (nation string, o_year string, sum_profit double);
 
-set mapred.min.split.size=536870912;
-set hive.exec.reducers.bytes.per.reducer=1024000000;
-
 -- the query
 insert overwrite table q9_product_type_profit
 select 
diff --git a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/u8_order_by.hive b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/u8_order_by.hive
new file mode 100644
index 0000000..6efd2ae
--- /dev/null
+++ b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/queries/u8_order_by.hive
@@ -0,0 +1,8 @@
+drop table IF EXISTS nation;
+drop table IF EXISTS u8_non_mapred;
+
+create external table nation (N_NATIONKEY INT, N_NAME STRING, N_REGIONKEY INT, N_COMMENT STRING) ROW FORMAT DELIMITED FIELDS TERMINATED BY '|' STORED AS TEXTFILE LOCATION '/tpch/nation';
+create table u8_order_by (N_NATIONKEY INT, N_NAME STRING, N_REGIONKEY INT, N_COMMENT STRING);
+
+insert overwrite table u8_order_by
+select * FROM nation order by N_NATIONKEY;
diff --git a/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/results/u8_order_by.result b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/results/u8_order_by.result
new file mode 100644
index 0000000..719b246
--- /dev/null
+++ b/hivesterix/hivesterix-dist/src/test/resources/runtimefunctionts/results/u8_order_by.result
@@ -0,0 +1,25 @@
+0ALGERIA0 haggle. carefully final deposits detect slyly agai
+1ARGENTINA1al foxes promise slyly according to the regular accounts. bold requests alon
+2BRAZIL1y alongside of the pending deposits. carefully special packages are about the ironic forges. slyly special 
+3CANADA1eas hang ironic, silent packages. slyly regular packages are furiously over the tithes. fluffily bold
+4EGYPT4y above the carefully unusual theodolites. final dugouts are quickly across the furiously regular d
+5ETHIOPIA0ven packages wake quickly. regu
+6FRANCE3refully final requests. regular, ironi
+7GERMANY3l platelets. regular accounts x-ray: unusual, regular acco
+8INDIA2ss excuses cajole slyly across the packages. deposits print aroun
+9INDONESIA2 slyly express asymptotes. regular deposits haggle slyly. carefully ironic hockey players sleep blithely. carefull
+10IRAN4efully alongside of the slyly final dependencies. 
+11IRAQ4nic deposits boost atop the quickly final requests? quickly regula
+12JAPAN2ously. final, express gifts cajole a
+13JORDAN4ic deposits are blithely about the carefully regular pa
+14KENYA0 pending excuses haggle furiously deposits. pending, express pinto beans wake fluffily past t
+15MOROCCO0rns. blithely bold courts among the closely regular packages use furiously bold platelets?
+16MOZAMBIQUE0s. ironic, unusual asymptotes wake blithely r
+17PERU1platelets. blithely pending dependencies use fluffily across the even pinto beans. carefully silent accoun
+18CHINA2c dependencies. furiously express notornis sleep slyly regular accounts. ideas sleep. depos
+19ROMANIA3ular asymptotes are about the furious multipliers. express dependencies nag above the ironically ironic account
+20SAUDI ARABIA4ts. silent requests haggle. closely express packages sleep across the blithely
+21VIETNAM2hely enticingly express accounts. even, final 
+22RUSSIA3 requests against the platelets use never according to the quickly regular pint
+23UNITED KINGDOM3eans boost carefully special requests. accounts are. carefull
+24UNITED STATES1y final packages. slow foxes cajole quickly. quickly silent platelets breach ironic accounts. unusual pinto be
diff --git a/hivesterix/hivesterix-optimizer/pom.xml b/hivesterix/hivesterix-optimizer/pom.xml
index ba7c7ad..858507e 100644
--- a/hivesterix/hivesterix-optimizer/pom.xml
+++ b/hivesterix/hivesterix-optimizer/pom.xml
@@ -18,7 +18,7 @@
 	<parent>
 		<artifactId>hivesterix</artifactId>
 		<groupId>edu.uci.ics.hyracks</groupId>
-		<version>0.2.7-SNAPSHOT</version>
+		<version>0.2.10-SNAPSHOT</version>
 	</parent>
 
 	<artifactId>hivesterix-optimizer</artifactId>
@@ -44,14 +44,14 @@
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hivesterix-common</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hivesterix-translator</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
diff --git a/hivesterix/hivesterix-optimizer/src/main/java/edu/uci/ics/hivesterix/optimizer/rulecollections/HiveRuleCollections.java b/hivesterix/hivesterix-optimizer/src/main/java/edu/uci/ics/hivesterix/optimizer/rulecollections/HiveRuleCollections.java
index 959e73e..12b5986 100644
--- a/hivesterix/hivesterix-optimizer/src/main/java/edu/uci/ics/hivesterix/optimizer/rulecollections/HiveRuleCollections.java
+++ b/hivesterix/hivesterix-optimizer/src/main/java/edu/uci/ics/hivesterix/optimizer/rulecollections/HiveRuleCollections.java
@@ -12,115 +12,116 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package edu.uci.ics.hivesterix.optimizer.rulecollections;
-
-import java.util.LinkedList;
-
-import edu.uci.ics.hivesterix.optimizer.rules.InsertProjectBeforeWriteRule;
-import edu.uci.ics.hivesterix.optimizer.rules.IntroduceEarlyProjectRule;
-import edu.uci.ics.hivesterix.optimizer.rules.LocalGroupByRule;
-import edu.uci.ics.hivesterix.optimizer.rules.RemoveRedundantSelectRule;
-import edu.uci.ics.hyracks.algebricks.core.rewriter.base.HeuristicOptimizer;
-import edu.uci.ics.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.BreakSelectIntoConjunctsRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.ComplexJoinInferenceRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.ConsolidateAssignsRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.ConsolidateSelectsRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.EliminateSubplanRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.EnforceStructuralPropertiesRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.ExtractCommonOperatorsRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.ExtractGbyExpressionsRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.FactorRedundantGroupAndDecorVarsRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.InferTypesRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.InlineVariablesRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.InsertProjectBeforeUnionRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.IntroduceAggregateCombinerRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.IntroduceGroupByCombinerRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.IsolateHyracksOperatorsRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.PullSelectOutOfEqJoin;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.PushLimitDownRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.PushProjectDownRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.PushProjectIntoDataSourceScanRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.PushSelectDownRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.PushSelectIntoJoinRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.ReinferAllTypesRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.RemoveRedundantProjectionRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.RemoveUnusedAssignAndAggregateRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.SetAlgebricksPhysicalOperatorsRule;
-import edu.uci.ics.hyracks.algebricks.rewriter.rules.SetExecutionModeRule;
-
-public final class HiveRuleCollections {
-
-    public final static LinkedList<IAlgebraicRewriteRule> NORMALIZATION = new LinkedList<IAlgebraicRewriteRule>();
-    static {
-        NORMALIZATION.add(new EliminateSubplanRule());
-        NORMALIZATION.add(new BreakSelectIntoConjunctsRule());
-        NORMALIZATION.add(new PushSelectIntoJoinRule());
-        NORMALIZATION.add(new ExtractGbyExpressionsRule());
-        NORMALIZATION.add(new RemoveRedundantSelectRule());
-    }
-
-    public final static LinkedList<IAlgebraicRewriteRule> COND_PUSHDOWN_AND_JOIN_INFERENCE = new LinkedList<IAlgebraicRewriteRule>();
-    static {
-        COND_PUSHDOWN_AND_JOIN_INFERENCE.add(new PushSelectDownRule());
-        COND_PUSHDOWN_AND_JOIN_INFERENCE.add(new InlineVariablesRule());
-        COND_PUSHDOWN_AND_JOIN_INFERENCE.add(new FactorRedundantGroupAndDecorVarsRule());
-        COND_PUSHDOWN_AND_JOIN_INFERENCE.add(new EliminateSubplanRule());
-    }
-
-    public final static LinkedList<IAlgebraicRewriteRule> LOAD_FIELDS = new LinkedList<IAlgebraicRewriteRule>();
-    static {
-        // should LoadRecordFieldsRule be applied in only one pass over the
-        // plan?
-        LOAD_FIELDS.add(new InlineVariablesRule());
-        // LOAD_FIELDS.add(new RemoveUnusedAssignAndAggregateRule());
-        LOAD_FIELDS.add(new ComplexJoinInferenceRule());
-        LOAD_FIELDS.add(new InferTypesRule());
-    }
-
-    public final static LinkedList<IAlgebraicRewriteRule> OP_PUSHDOWN = new LinkedList<IAlgebraicRewriteRule>();
-    static {
-        OP_PUSHDOWN.add(new PushProjectDownRule());
-        OP_PUSHDOWN.add(new PushSelectDownRule());
-    }
-
-    public final static LinkedList<IAlgebraicRewriteRule> DATA_EXCHANGE = new LinkedList<IAlgebraicRewriteRule>();
-    static {
-        DATA_EXCHANGE.add(new SetExecutionModeRule());
-    }
-
-    public final static LinkedList<IAlgebraicRewriteRule> CONSOLIDATION = new LinkedList<IAlgebraicRewriteRule>();
-    static {
-        CONSOLIDATION.add(new RemoveRedundantProjectionRule());
-        CONSOLIDATION.add(new ConsolidateSelectsRule());
-        CONSOLIDATION.add(new IntroduceEarlyProjectRule());
-        CONSOLIDATION.add(new ConsolidateAssignsRule());
-        CONSOLIDATION.add(new IntroduceGroupByCombinerRule());
-        CONSOLIDATION.add(new IntroduceAggregateCombinerRule());
-        CONSOLIDATION.add(new RemoveUnusedAssignAndAggregateRule());
-    }
-
-    public final static LinkedList<IAlgebraicRewriteRule> PHYSICAL_PLAN_REWRITES = new LinkedList<IAlgebraicRewriteRule>();
-    static {
-        PHYSICAL_PLAN_REWRITES.add(new PullSelectOutOfEqJoin());
-        PHYSICAL_PLAN_REWRITES.add(new SetAlgebricksPhysicalOperatorsRule());
-        PHYSICAL_PLAN_REWRITES.add(new EnforceStructuralPropertiesRule());
-        PHYSICAL_PLAN_REWRITES.add(new PushProjectDownRule());
-        PHYSICAL_PLAN_REWRITES.add(new SetAlgebricksPhysicalOperatorsRule());
-        PHYSICAL_PLAN_REWRITES.add(new PushLimitDownRule());
-        PHYSICAL_PLAN_REWRITES.add(new InsertProjectBeforeWriteRule());
-        PHYSICAL_PLAN_REWRITES.add(new InsertProjectBeforeUnionRule());
-    }
-
-    public final static LinkedList<IAlgebraicRewriteRule> prepareJobGenRules = new LinkedList<IAlgebraicRewriteRule>();
-    static {
-        prepareJobGenRules.add(new ReinferAllTypesRule());
-        prepareJobGenRules.add(new IsolateHyracksOperatorsRule(
-                HeuristicOptimizer.hyraxOperatorsBelowWhichJobGenIsDisabled));
-        prepareJobGenRules.add(new ExtractCommonOperatorsRule());
-        prepareJobGenRules.add(new LocalGroupByRule());
-        prepareJobGenRules.add(new PushProjectIntoDataSourceScanRule());
-        prepareJobGenRules.add(new ReinferAllTypesRule());
-    }
-
-}
+package edu.uci.ics.hivesterix.optimizer.rulecollections;
+
+import java.util.LinkedList;
+
+import edu.uci.ics.hivesterix.optimizer.rules.InsertProjectBeforeWriteRule;
+import edu.uci.ics.hivesterix.optimizer.rules.IntroduceEarlyProjectRule;
+import edu.uci.ics.hivesterix.optimizer.rules.LocalGroupByRule;
+import edu.uci.ics.hivesterix.optimizer.rules.RemoveRedundantSelectRule;
+import edu.uci.ics.hyracks.algebricks.core.rewriter.base.HeuristicOptimizer;
+import edu.uci.ics.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.BreakSelectIntoConjunctsRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.ComplexJoinInferenceRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.ConsolidateAssignsRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.ConsolidateSelectsRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.EliminateSubplanRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.EnforceStructuralPropertiesRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.ExtractCommonOperatorsRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.ExtractGbyExpressionsRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.FactorRedundantGroupAndDecorVarsRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.InferTypesRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.InlineVariablesRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.InsertProjectBeforeUnionRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.IntroduceAggregateCombinerRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.IntroduceGroupByCombinerRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.IsolateHyracksOperatorsRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.PullSelectOutOfEqJoin;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.PushLimitDownRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.PushProjectDownRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.PushProjectIntoDataSourceScanRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.PushSelectDownRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.PushSelectIntoJoinRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.ReinferAllTypesRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.RemoveRedundantProjectionRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.RemoveUnusedAssignAndAggregateRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.SetAlgebricksPhysicalOperatorsRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.SetExecutionModeRule;
+
+public final class HiveRuleCollections {
+
+    public final static LinkedList<IAlgebraicRewriteRule> NORMALIZATION = new LinkedList<IAlgebraicRewriteRule>();
+    static {
+        NORMALIZATION.add(new EliminateSubplanRule());
+        NORMALIZATION.add(new BreakSelectIntoConjunctsRule());
+        NORMALIZATION.add(new PushSelectIntoJoinRule());
+        NORMALIZATION.add(new ExtractGbyExpressionsRule());
+        NORMALIZATION.add(new RemoveRedundantSelectRule());
+    }
+
+    public final static LinkedList<IAlgebraicRewriteRule> COND_PUSHDOWN_AND_JOIN_INFERENCE = new LinkedList<IAlgebraicRewriteRule>();
+    static {
+        COND_PUSHDOWN_AND_JOIN_INFERENCE.add(new PushSelectDownRule());
+        COND_PUSHDOWN_AND_JOIN_INFERENCE.add(new InlineVariablesRule());
+        COND_PUSHDOWN_AND_JOIN_INFERENCE.add(new FactorRedundantGroupAndDecorVarsRule());
+        COND_PUSHDOWN_AND_JOIN_INFERENCE.add(new EliminateSubplanRule());
+    }
+
+    public final static LinkedList<IAlgebraicRewriteRule> LOAD_FIELDS = new LinkedList<IAlgebraicRewriteRule>();
+    static {
+        // should LoadRecordFieldsRule be applied in only one pass over the
+        // plan?
+        LOAD_FIELDS.add(new InlineVariablesRule());
+        // LOAD_FIELDS.add(new RemoveUnusedAssignAndAggregateRule());
+        LOAD_FIELDS.add(new ComplexJoinInferenceRule());
+        LOAD_FIELDS.add(new InferTypesRule());
+    }
+
+    public final static LinkedList<IAlgebraicRewriteRule> OP_PUSHDOWN = new LinkedList<IAlgebraicRewriteRule>();
+    static {
+        OP_PUSHDOWN.add(new PushProjectDownRule());
+        OP_PUSHDOWN.add(new PushSelectDownRule());
+    }
+
+    public final static LinkedList<IAlgebraicRewriteRule> DATA_EXCHANGE = new LinkedList<IAlgebraicRewriteRule>();
+    static {
+        DATA_EXCHANGE.add(new SetExecutionModeRule());
+    }
+
+    public final static LinkedList<IAlgebraicRewriteRule> CONSOLIDATION = new LinkedList<IAlgebraicRewriteRule>();
+    static {
+        CONSOLIDATION.add(new RemoveRedundantProjectionRule());
+        CONSOLIDATION.add(new ConsolidateSelectsRule());
+        CONSOLIDATION.add(new IntroduceEarlyProjectRule());
+        CONSOLIDATION.add(new ConsolidateAssignsRule());
+        CONSOLIDATION.add(new IntroduceGroupByCombinerRule());
+        CONSOLIDATION.add(new IntroduceAggregateCombinerRule());
+        CONSOLIDATION.add(new RemoveUnusedAssignAndAggregateRule());
+    }
+
+    public final static LinkedList<IAlgebraicRewriteRule> PHYSICAL_PLAN_REWRITES = new LinkedList<IAlgebraicRewriteRule>();
+    static {
+        PHYSICAL_PLAN_REWRITES.add(new PullSelectOutOfEqJoin());
+        PHYSICAL_PLAN_REWRITES.add(new SetAlgebricksPhysicalOperatorsRule());
+        PHYSICAL_PLAN_REWRITES.add(new EnforceStructuralPropertiesRule());
+        PHYSICAL_PLAN_REWRITES.add(new PushProjectDownRule());
+        PHYSICAL_PLAN_REWRITES.add(new SetAlgebricksPhysicalOperatorsRule());
+        PHYSICAL_PLAN_REWRITES.add(new PushLimitDownRule());
+        PHYSICAL_PLAN_REWRITES.add(new InsertProjectBeforeWriteRule());
+        PHYSICAL_PLAN_REWRITES.add(new InsertProjectBeforeUnionRule());
+    }
+
+    public final static LinkedList<IAlgebraicRewriteRule> prepareJobGenRules = new LinkedList<IAlgebraicRewriteRule>();
+    static {
+        prepareJobGenRules.add(new ReinferAllTypesRule());
+        prepareJobGenRules.add(new IsolateHyracksOperatorsRule(
+                HeuristicOptimizer.hyraxOperatorsBelowWhichJobGenIsDisabled));
+        prepareJobGenRules.add(new ExtractCommonOperatorsRule());
+        prepareJobGenRules.add(new LocalGroupByRule());
+        prepareJobGenRules.add(new PushProjectIntoDataSourceScanRule());
+        prepareJobGenRules.add(new ReinferAllTypesRule());
+        prepareJobGenRules.add(new SetExecutionModeRule());
+    }
+
+}
diff --git a/hivesterix/hivesterix-runtime/pom.xml b/hivesterix/hivesterix-runtime/pom.xml
index e4f5416..6d10286 100644
--- a/hivesterix/hivesterix-runtime/pom.xml
+++ b/hivesterix/hivesterix-runtime/pom.xml
@@ -20,16 +20,14 @@
 	<parent>
                 <groupId>edu.uci.ics.hyracks</groupId>
                 <artifactId>hivesterix</artifactId>
-                <version>0.2.7-SNAPSHOT</version>
+                <version>0.2.10-SNAPSHOT</version>
         </parent>
 
 	<dependencies>
-        <dependency>
-			<groupId>javax.servlet</groupId>
-			<artifactId>servlet-api</artifactId>
-			<version>2.5</version>
-			<type>jar</type>
-			<scope>compile</scope>
+		<dependency>
+  			<groupId>sqlline</groupId>
+  			<artifactId>sqlline</artifactId>
+  			<version>1_0_2</version>
 		</dependency>
 		<dependency>
 			<groupId>junit</groupId>
@@ -38,285 +36,105 @@
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
-			<groupId>args4j</groupId>
-			<artifactId>args4j</artifactId>
-			<version>2.0.12</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.json</groupId>
-			<artifactId>json</artifactId>
-			<version>20090211</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.eclipse.jetty</groupId>
-			<artifactId>jetty-server</artifactId>
-			<version>8.0.0.M1</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.eclipse.jetty</groupId>
-			<artifactId>jetty-servlet</artifactId>
-			<version>8.0.0.M1</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>jline</groupId>
-			<artifactId>jline</artifactId>
-			<version>0.9.94</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.datanucleus</groupId>
-			<artifactId>datanucleus-core</artifactId>
-			<version>2.0.3</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.datanucleus</groupId>
-			<artifactId>datanucleus-connectionpool</artifactId>
-			<version>2.0.3</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.datanucleus</groupId>
-			<artifactId>datanucleus-enhancer</artifactId>
-			<version>2.0.3</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.datanucleus</groupId>
-			<artifactId>datanucleus-rdbms</artifactId>
-			<version>2.0.3</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>commons-dbcp</groupId>
-			<artifactId>commons-dbcp</artifactId>
-			<version>1.4</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>commons-pool</groupId>
-			<artifactId>commons-pool</artifactId>
-			<version>1.5.4</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>commons-collections</groupId>
-			<artifactId>commons-collections</artifactId>
-			<version>3.2.1</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>commons-lang</groupId>
-			<artifactId>commons-lang</artifactId>
-			<version>2.4</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>javax</groupId>
-			<artifactId>jdo2-api</artifactId>
-			<version>2.3-ec</version>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>com.facebook</groupId>
-			<artifactId>libfb303</artifactId>
-			<version>0.5.0</version>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.thrift</groupId>
-			<artifactId>libthrift</artifactId>
-			<version>0.5.0</version>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.commons</groupId>
-			<artifactId>cli</artifactId>
-			<version>1.2</version>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.apache</groupId>
-			<artifactId>log4j</artifactId>
-			<version>1.2.15</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.antlr</groupId>
-			<artifactId>antlr-runtime</artifactId>
-			<version>3.0.1</version>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.hadoop.hive</groupId>
+			<groupId>org.apache.hive</groupId>
 			<artifactId>hive-cli</artifactId>
-			<version>0.7.0</version>
+			<version>0.11.0</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
-			<groupId>org.apache.hadoop.hive</groupId>
+			<groupId>org.apache.hive</groupId>
 			<artifactId>hive-common</artifactId>
-			<version>0.7.0</version>
+			<version>0.11.0</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
-			<groupId>org.apache.hadoop.hive</groupId>
+			<groupId>org.apache.hive</groupId>
 			<artifactId>hive-exec</artifactId>
-			<version>0.7.0</version>
+			<version>0.11.0</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
-			<groupId>org.apache.hadoop.hive</groupId>
+			<groupId>org.apache.hive</groupId>
 			<artifactId>hive-hwi</artifactId>
-			<version>0.7.0</version>
+			<version>0.11.0</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
-			<groupId>org.apache.hadoop.hive</groupId>
+			<groupId>org.apache.hive</groupId>
 			<artifactId>hive-jdbc</artifactId>
-			<version>0.7.0</version>
+			<version>0.11.0</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
-			<groupId>org.apache.hadoop.hive</groupId>
+			<groupId>org.apache.hive</groupId>
 			<artifactId>hive-metastore</artifactId>
-			<version>0.7.0</version>
+			<version>0.11.0</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
-			<groupId>org.apache.hadoop.hive</groupId>
+			<groupId>org.apache.hive</groupId>
 			<artifactId>hive-service</artifactId>
-			<version>0.7.0</version>
+			<version>0.11.0</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
-			<groupId>org.apache.hadoop.hive</groupId>
+			<groupId>org.apache.hive</groupId>
 			<artifactId>hive-shims</artifactId>
-			<version>0.7.0</version>
+			<version>0.11.0</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
-			<groupId>org.apache.hadoop.hive</groupId>
+			<groupId>org.apache.hive</groupId>
 			<artifactId>hive-serde</artifactId>
-			<version>0.7.0</version>
+			<version>0.11.0</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
-			<groupId>org.slf4j</groupId>
-			<artifactId>slf4j-api</artifactId>
-			<version>1.6.1</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>commons-cli</groupId>
-			<artifactId>commons-cli</artifactId>
-			<version>1.2</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.slf4j</groupId>
-			<artifactId>slf4j-log4j12</artifactId>
-			<version>1.6.1</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>commons-logging</groupId>
-			<artifactId>commons-logging</artifactId>
-			<version>1.1.1</version>
-			<type>jar</type>
-			<classifier>api</classifier>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>com.google.guava</groupId>
-			<artifactId>guava</artifactId>
-			<version>r06</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.antlr</groupId>
-			<artifactId>stringtemplate</artifactId>
-			<version>3.2</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.derby</groupId>
-			<artifactId>derby</artifactId>
-			<version>10.8.1.2</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.hbase</groupId>
-			<artifactId>hbase</artifactId>
-			<version>0.90.3</version>
-			<type>jar</type>
-			<scope>compile</scope>
+			<groupId>org.apache.hive</groupId>
+			<artifactId>hive-hbase-handler</artifactId>
+			<version>0.11.0</version>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>algebricks-compiler</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-control-cc</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-control-nc</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hivesterix-serde</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hivesterix-common</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
@@ -384,5 +202,19 @@
 			<id>hyracks-public-release</id>
 			<url>http://obelix.ics.uci.edu/nexus/content/repositories/hyracks-public-releases</url>
 		</repository>
+		<repository>
+			<releases>
+				<enabled>true</enabled>
+				<updatePolicy>always</updatePolicy>
+				<checksumPolicy>warn</checksumPolicy>
+			</releases>
+			<snapshots>
+				<enabled>true</enabled>
+				<updatePolicy>always</updatePolicy>
+				<checksumPolicy>fail</checksumPolicy>
+			</snapshots>
+			<id>plugins-release</id>
+			<url>http://repo.springsource.org/plugins-release</url>
+		</repository>
 	</repositories>
 </project>
diff --git a/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/evaluator/AbstractExpressionEvaluator.java b/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/evaluator/AbstractExpressionEvaluator.java
index a5177c9..dd4fbe7 100644
--- a/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/evaluator/AbstractExpressionEvaluator.java
+++ b/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/evaluator/AbstractExpressionEvaluator.java
@@ -34,6 +34,7 @@
 import edu.uci.ics.hyracks.data.std.api.IDataOutputProvider;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
 
+@SuppressWarnings("deprecation")
 public abstract class AbstractExpressionEvaluator implements ICopyEvaluator {
 
     private List<ICopyEvaluator> children;
diff --git a/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/evaluator/AggregationFunctionEvaluator.java b/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/evaluator/AggregationFunctionEvaluator.java
index d061b23..87d2221 100644
--- a/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/evaluator/AggregationFunctionEvaluator.java
+++ b/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/evaluator/AggregationFunctionEvaluator.java
@@ -36,6 +36,7 @@
 import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyAggregateFunction;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
 
+@SuppressWarnings("deprecation")
 public class AggregationFunctionEvaluator implements ICopyAggregateFunction {
 
     /**
diff --git a/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/evaluator/AggregatuibFunctionSerializableEvaluator.java b/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/evaluator/AggregatuibFunctionSerializableEvaluator.java
index f4b77b8..3f1cc27 100644
--- a/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/evaluator/AggregatuibFunctionSerializableEvaluator.java
+++ b/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/evaluator/AggregatuibFunctionSerializableEvaluator.java
@@ -35,6 +35,7 @@
 import edu.uci.ics.hyracks.algebricks.runtime.base.ICopySerializableAggregateFunction;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
 
+@SuppressWarnings("deprecation")
 public class AggregatuibFunctionSerializableEvaluator implements ICopySerializableAggregateFunction {
 
     /**
diff --git a/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/evaluator/UDTFFunctionEvaluator.java b/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/evaluator/UDTFFunctionEvaluator.java
index d91b806..b511d87 100644
--- a/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/evaluator/UDTFFunctionEvaluator.java
+++ b/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/evaluator/UDTFFunctionEvaluator.java
@@ -35,6 +35,7 @@
 import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyUnnestingFunction;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
 
+@SuppressWarnings("deprecation")
 public class UDTFFunctionEvaluator implements ICopyUnnestingFunction, Collector {
 
     /**
diff --git a/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/factory/evaluator/AggregationFunctionFactory.java b/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/factory/evaluator/AggregationFunctionFactory.java
index 09f0cb6..d65dc24 100644
--- a/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/factory/evaluator/AggregationFunctionFactory.java
+++ b/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/factory/evaluator/AggregationFunctionFactory.java
@@ -12,370 +12,383 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package edu.uci.ics.hivesterix.runtime.factory.evaluator;
-
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-
-import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.hive.ql.exec.ExprNodeEvaluator;
-import org.apache.hadoop.hive.ql.exec.ExprNodeEvaluatorFactory;
-import org.apache.hadoop.hive.ql.exec.FunctionRegistry;
-import org.apache.hadoop.hive.ql.exec.Utilities;
-import org.apache.hadoop.hive.ql.metadata.HiveException;
-import org.apache.hadoop.hive.ql.plan.AggregationDesc;
-import org.apache.hadoop.hive.ql.plan.ExprNodeDesc;
-import org.apache.hadoop.hive.ql.udf.generic.GenericUDAFEvaluator;
-import org.apache.hadoop.hive.serde2.SerDe;
-import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
-import org.apache.hadoop.hive.serde2.typeinfo.StructTypeInfo;
-import org.apache.hadoop.hive.serde2.typeinfo.TypeInfo;
-import org.apache.hadoop.hive.serde2.typeinfo.TypeInfoFactory;
-
-import edu.uci.ics.hivesterix.logical.expression.ExpressionTranslator;
-import edu.uci.ics.hivesterix.runtime.evaluator.AggregationFunctionEvaluator;
-import edu.uci.ics.hivesterix.runtime.jobgen.Schema;
-import edu.uci.ics.hivesterix.serde.lazy.LazyFactory;
-import edu.uci.ics.hivesterix.serde.lazy.LazyObject;
-import edu.uci.ics.hivesterix.serde.lazy.LazySerDe;
-import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
-import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.AggregateFunctionCallExpression;
-import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.IVariableTypeEnvironment;
-import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyAggregateFunction;
-import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyAggregateFunctionFactory;
-import edu.uci.ics.hyracks.data.std.api.IDataOutputProvider;
-
-public class AggregationFunctionFactory implements ICopyAggregateFunctionFactory {
-
-    private static final long serialVersionUID = 1L;
-
-    /**
-     * list of parameters' serialization
-     */
-    private List<String> parametersSerialization = new ArrayList<String>();
-
-    /**
-     * the name of the udf
-     */
-    private String genericUDAFName;
-
-    /**
-     * aggregation mode
-     */
-    private GenericUDAFEvaluator.Mode mode;
-
-    /**
-     * list of type info
-     */
-    private List<TypeInfo> types = new ArrayList<TypeInfo>();
-
-    /**
-     * distinct or not
-     */
-    private boolean distinct;
-
-    /**
-     * the schema of incoming rows
-     */
-    private Schema rowSchema;
-
-    /**
-     * list of parameters
-     */
-    private transient List<ExprNodeDesc> parametersOrigin;
-
-    /**
-     * row inspector
-     */
-    private transient ObjectInspector rowInspector = null;
-
-    /**
-     * output object inspector
-     */
-    private transient ObjectInspector outputInspector = null;
-
-    /**
-     * output object inspector
-     */
-    private transient ObjectInspector outputInspectorPartial = null;
-
-    /**
-     * parameter inspectors
-     */
-    private transient ObjectInspector[] parameterInspectors = null;
-
-    /**
-     * expression desc
-     */
-    private transient HashMap<Long, List<ExprNodeDesc>> parameterExprs = new HashMap<Long, List<ExprNodeDesc>>();
-
-    /**
-     * evaluators
-     */
-    private transient HashMap<Long, ExprNodeEvaluator[]> evaluators = new HashMap<Long, ExprNodeEvaluator[]>();
-
-    /**
-     * cached parameter objects
-     */
-    private transient HashMap<Long, Object[]> cachedParameters = new HashMap<Long, Object[]>();
-
-    /**
-     * cached row object: one per thread
-     */
-    private transient HashMap<Long, LazyObject<? extends ObjectInspector>> cachedRowObjects = new HashMap<Long, LazyObject<? extends ObjectInspector>>();
-
-    /**
-     * we only use lazy serde to do serialization
-     */
-    private transient HashMap<Long, SerDe> serDe = new HashMap<Long, SerDe>();
-
-    /**
-     * udaf evaluators
-     */
-    private transient HashMap<Long, GenericUDAFEvaluator> udafsPartial = new HashMap<Long, GenericUDAFEvaluator>();
-
-    /**
-     * udaf evaluators
-     */
-    private transient HashMap<Long, GenericUDAFEvaluator> udafsComplete = new HashMap<Long, GenericUDAFEvaluator>();
-
-    /**
-     * aggregation function desc
-     */
-    private transient AggregationDesc aggregator;
-
-    /**
-     * @param aggregator
-     *            Algebricks function call expression
-     * @param oi
-     *            schema
-     */
-    public AggregationFunctionFactory(AggregateFunctionCallExpression expression, Schema oi,
-            IVariableTypeEnvironment env) throws AlgebricksException {
-
-        try {
-            aggregator = (AggregationDesc) ExpressionTranslator.getHiveExpression(expression, env);
-        } catch (Exception e) {
-            e.printStackTrace();
-            throw new AlgebricksException(e.getMessage());
-        }
-        init(aggregator.getParameters(), aggregator.getGenericUDAFName(), aggregator.getMode(),
-                aggregator.getDistinct(), oi);
-    }
-
-    /**
-     * constructor of aggregation function factory
-     * 
-     * @param inputs
-     * @param name
-     * @param udafMode
-     * @param distinct
-     * @param oi
-     */
-    private void init(List<ExprNodeDesc> inputs, String name, GenericUDAFEvaluator.Mode udafMode, boolean distinct,
-            Schema oi) {
-        parametersOrigin = inputs;
-        genericUDAFName = name;
-        mode = udafMode;
-        this.distinct = distinct;
-        rowSchema = oi;
-
-        for (ExprNodeDesc input : inputs) {
-            TypeInfo type = input.getTypeInfo();
-            if (type instanceof StructTypeInfo) {
-                types.add(TypeInfoFactory.doubleTypeInfo);
-            } else
-                types.add(type);
-
-            String s = Utilities.serializeExpression(input);
-            parametersSerialization.add(s);
-        }
-    }
-
-    @Override
-    public synchronized ICopyAggregateFunction createAggregateFunction(IDataOutputProvider provider)
-            throws AlgebricksException {
-        if (parametersOrigin == null) {
-            Configuration config = new Configuration();
-            config.setClassLoader(this.getClass().getClassLoader());
-            /**
-             * in case of class.forname(...) call in hive code
-             */
-            Thread.currentThread().setContextClassLoader(this.getClass().getClassLoader());
-
-            parametersOrigin = new ArrayList<ExprNodeDesc>();
-            for (String serialization : parametersSerialization) {
-                parametersOrigin.add(Utilities.deserializeExpression(serialization, config));
-            }
-        }
-
-        /**
-         * exprs
-         */
-        if (parameterExprs == null)
-            parameterExprs = new HashMap<Long, List<ExprNodeDesc>>();
-
-        /**
-         * evaluators
-         */
-        if (evaluators == null)
-            evaluators = new HashMap<Long, ExprNodeEvaluator[]>();
-
-        /**
-         * cached parameter objects
-         */
-        if (cachedParameters == null)
-            cachedParameters = new HashMap<Long, Object[]>();
-
-        /**
-         * cached row object: one per thread
-         */
-        if (cachedRowObjects == null)
-            cachedRowObjects = new HashMap<Long, LazyObject<? extends ObjectInspector>>();
-
-        /**
-         * we only use lazy serde to do serialization
-         */
-        if (serDe == null)
-            serDe = new HashMap<Long, SerDe>();
-
-        /**
-         * UDAF functions
-         */
-        if (udafsComplete == null)
-            udafsComplete = new HashMap<Long, GenericUDAFEvaluator>();
-
-        /**
-         * UDAF functions
-         */
-        if (udafsPartial == null)
-            udafsPartial = new HashMap<Long, GenericUDAFEvaluator>();
-
-        if (parameterInspectors == null)
-            parameterInspectors = new ObjectInspector[parametersOrigin.size()];
-
-        if (rowInspector == null)
-            rowInspector = rowSchema.toObjectInspector();
-
-        // get current thread id
-        long threadId = Thread.currentThread().getId();
-
-        /**
-         * expressions, expressions are thread local
-         */
-        List<ExprNodeDesc> parameters = parameterExprs.get(threadId);
-        if (parameters == null) {
-            parameters = new ArrayList<ExprNodeDesc>();
-            for (ExprNodeDesc parameter : parametersOrigin)
-                parameters.add(parameter.clone());
-            parameterExprs.put(threadId, parameters);
-        }
-
-        /**
-         * cached parameter objects
-         */
-        Object[] cachedParas = cachedParameters.get(threadId);
-        if (cachedParas == null) {
-            cachedParas = new Object[parameters.size()];
-            cachedParameters.put(threadId, cachedParas);
-        }
-
-        /**
-         * cached row object: one per thread
-         */
-        LazyObject<? extends ObjectInspector> cachedRowObject = cachedRowObjects.get(threadId);
-        if (cachedRowObject == null) {
-            cachedRowObject = LazyFactory.createLazyObject(rowInspector);
-            cachedRowObjects.put(threadId, cachedRowObject);
-        }
-
-        /**
-         * we only use lazy serde to do serialization
-         */
-        SerDe lazySer = serDe.get(threadId);
-        if (lazySer == null) {
-            lazySer = new LazySerDe();
-            serDe.put(threadId, lazySer);
-        }
-
-        /**
-         * evaluators
-         */
-        ExprNodeEvaluator[] evals = evaluators.get(threadId);
-        if (evals == null) {
-            evals = new ExprNodeEvaluator[parameters.size()];
-            evaluators.put(threadId, evals);
-        }
-
-        GenericUDAFEvaluator udafPartial;
-        GenericUDAFEvaluator udafComplete;
-
-        // initialize object inspectors
-        try {
-            /**
-             * evaluators, udf, object inpsectors are shared in one thread
-             */
-            for (int i = 0; i < evals.length; i++) {
-                if (evals[i] == null) {
-                    evals[i] = ExprNodeEvaluatorFactory.get(parameters.get(i));
-                    if (parameterInspectors[i] == null) {
-                        parameterInspectors[i] = evals[i].initialize(rowInspector);
-                    } else {
-                        evals[i].initialize(rowInspector);
-                    }
-                }
-            }
-
-            udafComplete = udafsComplete.get(threadId);
-            if (udafComplete == null) {
-                try {
-                    udafComplete = FunctionRegistry.getGenericUDAFEvaluator(genericUDAFName, types, distinct, false);
-                } catch (HiveException e) {
-                    throw new AlgebricksException(e);
-                }
-                udafsComplete.put(threadId, udafComplete);
-                udafComplete.init(mode, parameterInspectors);
-            }
-
-            // multiple stage group by, determined by the mode parameter
-            if (outputInspector == null)
-                outputInspector = udafComplete.init(mode, parameterInspectors);
-
-            // initial partial gby udaf
-            GenericUDAFEvaluator.Mode partialMode;
-            // adjust mode for external groupby
-            if (mode == GenericUDAFEvaluator.Mode.COMPLETE)
-                partialMode = GenericUDAFEvaluator.Mode.PARTIAL1;
-            else if (mode == GenericUDAFEvaluator.Mode.FINAL)
-                partialMode = GenericUDAFEvaluator.Mode.PARTIAL2;
-            else
-                partialMode = mode;
-            udafPartial = udafsPartial.get(threadId);
-            if (udafPartial == null) {
-                try {
-                    udafPartial = FunctionRegistry.getGenericUDAFEvaluator(genericUDAFName, types, distinct, false);
-                } catch (HiveException e) {
-                    throw new AlgebricksException(e);
-                }
-                udafPartial.init(partialMode, parameterInspectors);
-                udafsPartial.put(threadId, udafPartial);
-            }
-
-            // multiple stage group by, determined by the mode parameter
-            if (outputInspectorPartial == null)
-                outputInspectorPartial = udafPartial.init(partialMode, parameterInspectors);
-        } catch (Exception e) {
-            e.printStackTrace();
-            throw new AlgebricksException(e);
-        }
-
-        return new AggregationFunctionEvaluator(parameters, types, genericUDAFName, mode, distinct, rowInspector,
-                provider.getDataOutput(), evals, parameterInspectors, cachedParas, lazySer, cachedRowObject,
-                udafPartial, udafComplete, outputInspector, outputInspectorPartial);
-    }
-
-    public String toString() {
-        return "aggregation function expression evaluator factory: " + this.genericUDAFName;
-    }
-}
+package edu.uci.ics.hivesterix.runtime.factory.evaluator;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hive.ql.exec.ExprNodeEvaluator;
+import org.apache.hadoop.hive.ql.exec.ExprNodeEvaluatorFactory;
+import org.apache.hadoop.hive.ql.exec.FunctionRegistry;
+import org.apache.hadoop.hive.ql.exec.Utilities;
+import org.apache.hadoop.hive.ql.metadata.HiveException;
+import org.apache.hadoop.hive.ql.plan.AggregationDesc;
+import org.apache.hadoop.hive.ql.plan.ExprNodeDesc;
+import org.apache.hadoop.hive.ql.udf.generic.GenericUDAFEvaluator;
+import org.apache.hadoop.hive.serde2.SerDe;
+import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
+import org.apache.hadoop.hive.serde2.typeinfo.StructTypeInfo;
+import org.apache.hadoop.hive.serde2.typeinfo.TypeInfo;
+import org.apache.hadoop.hive.serde2.typeinfo.TypeInfoFactory;
+
+import edu.uci.ics.hivesterix.logical.expression.ExpressionTranslator;
+import edu.uci.ics.hivesterix.runtime.evaluator.AggregationFunctionEvaluator;
+import edu.uci.ics.hivesterix.runtime.jobgen.Schema;
+import edu.uci.ics.hivesterix.serde.lazy.LazyFactory;
+import edu.uci.ics.hivesterix.serde.lazy.LazyObject;
+import edu.uci.ics.hivesterix.serde.lazy.LazySerDe;
+import edu.uci.ics.hivesterix.serde.lazy.LazyUtils;
+import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
+import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.AggregateFunctionCallExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.IVariableTypeEnvironment;
+import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyAggregateFunction;
+import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyAggregateFunctionFactory;
+import edu.uci.ics.hyracks.data.std.api.IDataOutputProvider;
+
+@SuppressWarnings("deprecation")
+public class AggregationFunctionFactory implements ICopyAggregateFunctionFactory {
+
+    private static final long serialVersionUID = 1L;
+
+    /**
+     * list of parameters' serialization
+     */
+    private List<String> parametersSerialization = new ArrayList<String>();
+
+    /**
+     * the name of the udf
+     */
+    private String genericUDAFName;
+
+    /**
+     * aggregation mode
+     */
+    private GenericUDAFEvaluator.Mode mode;
+
+    /**
+     * list of type info
+     */
+    private List<TypeInfo> types = new ArrayList<TypeInfo>();
+
+    /**
+     * distinct or not
+     */
+    private boolean distinct;
+
+    /**
+     * the schema of incoming rows
+     */
+    private Schema rowSchema;
+
+    /**
+     * list of parameters
+     */
+    private transient List<ExprNodeDesc> parametersOrigin;
+
+    /**
+     * row inspector
+     */
+    private transient ObjectInspector rowInspector = null;
+
+    /**
+     * output object inspector
+     */
+    private transient ObjectInspector outputInspector = null;
+
+    /**
+     * output object inspector
+     */
+    private transient ObjectInspector outputInspectorPartial = null;
+
+    /**
+     * parameter inspectors
+     */
+    private transient ObjectInspector[] parameterInspectors = null;
+
+    /**
+     * expression desc
+     */
+    private transient HashMap<Long, List<ExprNodeDesc>> parameterExprs = new HashMap<Long, List<ExprNodeDesc>>();
+
+    /**
+     * evaluators
+     */
+    private transient HashMap<Long, ExprNodeEvaluator[]> evaluators = new HashMap<Long, ExprNodeEvaluator[]>();
+
+    /**
+     * cached parameter objects
+     */
+    private transient HashMap<Long, Object[]> cachedParameters = new HashMap<Long, Object[]>();
+
+    /**
+     * cached row object: one per thread
+     */
+    private transient HashMap<Long, LazyObject<? extends ObjectInspector>> cachedRowObjects = new HashMap<Long, LazyObject<? extends ObjectInspector>>();
+
+    /**
+     * we only use lazy serde to do serialization
+     */
+    private transient HashMap<Long, SerDe> serDe = new HashMap<Long, SerDe>();
+
+    /**
+     * udaf evaluators
+     */
+    private transient HashMap<Long, GenericUDAFEvaluator> udafsPartial = new HashMap<Long, GenericUDAFEvaluator>();
+
+    /**
+     * udaf evaluators
+     */
+    private transient HashMap<Long, GenericUDAFEvaluator> udafsComplete = new HashMap<Long, GenericUDAFEvaluator>();
+
+    /**
+     * aggregation function desc
+     */
+    private transient AggregationDesc aggregator;
+
+    /**
+     * @param aggregator
+     *            Algebricks function call expression
+     * @param oi
+     *            schema
+     */
+    public AggregationFunctionFactory(AggregateFunctionCallExpression expression, Schema oi,
+            IVariableTypeEnvironment env) throws AlgebricksException {
+
+        try {
+            aggregator = (AggregationDesc) ExpressionTranslator.getHiveExpression(expression, env);
+        } catch (Exception e) {
+            e.printStackTrace();
+            throw new AlgebricksException(e.getMessage());
+        }
+        init(aggregator.getParameters(), aggregator.getGenericUDAFName(), aggregator.getMode(),
+                aggregator.getDistinct(), oi);
+    }
+
+    /**
+     * constructor of aggregation function factory
+     * 
+     * @param inputs
+     * @param name
+     * @param udafMode
+     * @param distinct
+     * @param oi
+     */
+    private void init(List<ExprNodeDesc> inputs, String name, GenericUDAFEvaluator.Mode udafMode, boolean distinct,
+            Schema oi) {
+        parametersOrigin = inputs;
+        genericUDAFName = name;
+        mode = udafMode;
+        this.distinct = distinct;
+        rowSchema = oi;
+
+        for (ExprNodeDesc input : inputs) {
+            TypeInfo type = input.getTypeInfo();
+            if (type instanceof StructTypeInfo) {
+                types.add(TypeInfoFactory.doubleTypeInfo);
+            } else {
+                types.add(type);
+            }
+
+            String s = Utilities.serializeExpression(input);
+            parametersSerialization.add(s);
+        }
+    }
+
+    @Override
+    public synchronized ICopyAggregateFunction createAggregateFunction(IDataOutputProvider provider)
+            throws AlgebricksException {
+        /**
+         * list of object inspectors correlated to types
+         */
+        List<ObjectInspector> oiListForTypes = new ArrayList<ObjectInspector>();
+        for (TypeInfo type : types) {
+            oiListForTypes.add(LazyUtils.getLazyObjectInspectorFromTypeInfo(type, false));
+        }
+
+        if (parametersOrigin == null) {
+            Configuration config = new Configuration();
+            config.setClassLoader(this.getClass().getClassLoader());
+            /**
+             * in case of class.forname(...) call in hive code
+             */
+            Thread.currentThread().setContextClassLoader(this.getClass().getClassLoader());
+
+            parametersOrigin = new ArrayList<ExprNodeDesc>();
+            for (String serialization : parametersSerialization) {
+                parametersOrigin.add(Utilities.deserializeExpression(serialization, config));
+            }
+        }
+
+        /**
+         * exprs
+         */
+        if (parameterExprs == null)
+            parameterExprs = new HashMap<Long, List<ExprNodeDesc>>();
+
+        /**
+         * evaluators
+         */
+        if (evaluators == null)
+            evaluators = new HashMap<Long, ExprNodeEvaluator[]>();
+
+        /**
+         * cached parameter objects
+         */
+        if (cachedParameters == null)
+            cachedParameters = new HashMap<Long, Object[]>();
+
+        /**
+         * cached row object: one per thread
+         */
+        if (cachedRowObjects == null)
+            cachedRowObjects = new HashMap<Long, LazyObject<? extends ObjectInspector>>();
+
+        /**
+         * we only use lazy serde to do serialization
+         */
+        if (serDe == null)
+            serDe = new HashMap<Long, SerDe>();
+
+        /**
+         * UDAF functions
+         */
+        if (udafsComplete == null)
+            udafsComplete = new HashMap<Long, GenericUDAFEvaluator>();
+
+        /**
+         * UDAF functions
+         */
+        if (udafsPartial == null)
+            udafsPartial = new HashMap<Long, GenericUDAFEvaluator>();
+
+        if (parameterInspectors == null)
+            parameterInspectors = new ObjectInspector[parametersOrigin.size()];
+
+        if (rowInspector == null)
+            rowInspector = rowSchema.toObjectInspector();
+
+        // get current thread id
+        long threadId = Thread.currentThread().getId();
+
+        /**
+         * expressions, expressions are thread local
+         */
+        List<ExprNodeDesc> parameters = parameterExprs.get(threadId);
+        if (parameters == null) {
+            parameters = new ArrayList<ExprNodeDesc>();
+            for (ExprNodeDesc parameter : parametersOrigin)
+                parameters.add(parameter.clone());
+            parameterExprs.put(threadId, parameters);
+        }
+
+        /**
+         * cached parameter objects
+         */
+        Object[] cachedParas = cachedParameters.get(threadId);
+        if (cachedParas == null) {
+            cachedParas = new Object[parameters.size()];
+            cachedParameters.put(threadId, cachedParas);
+        }
+
+        /**
+         * cached row object: one per thread
+         */
+        LazyObject<? extends ObjectInspector> cachedRowObject = cachedRowObjects.get(threadId);
+        if (cachedRowObject == null) {
+            cachedRowObject = LazyFactory.createLazyObject(rowInspector);
+            cachedRowObjects.put(threadId, cachedRowObject);
+        }
+
+        /**
+         * we only use lazy serde to do serialization
+         */
+        SerDe lazySer = serDe.get(threadId);
+        if (lazySer == null) {
+            lazySer = new LazySerDe();
+            serDe.put(threadId, lazySer);
+        }
+
+        /**
+         * evaluators
+         */
+        ExprNodeEvaluator[] evals = evaluators.get(threadId);
+        if (evals == null) {
+            evals = new ExprNodeEvaluator[parameters.size()];
+            evaluators.put(threadId, evals);
+        }
+
+        GenericUDAFEvaluator udafPartial;
+        GenericUDAFEvaluator udafComplete;
+
+        // initialize object inspectors
+        try {
+            /**
+             * evaluators, udf, object inpsectors are shared in one thread
+             */
+            for (int i = 0; i < evals.length; i++) {
+                if (evals[i] == null) {
+                    evals[i] = ExprNodeEvaluatorFactory.get(parameters.get(i));
+                    if (parameterInspectors[i] == null) {
+                        parameterInspectors[i] = evals[i].initialize(rowInspector);
+                    } else {
+                        evals[i].initialize(rowInspector);
+                    }
+                }
+            }
+
+            udafComplete = udafsComplete.get(threadId);
+            if (udafComplete == null) {
+                try {
+                    udafComplete = FunctionRegistry.getGenericUDAFEvaluator(genericUDAFName, oiListForTypes, distinct,
+                            false);
+                } catch (HiveException e) {
+                    throw new AlgebricksException(e);
+                }
+                udafsComplete.put(threadId, udafComplete);
+                udafComplete.init(mode, parameterInspectors);
+            }
+
+            // multiple stage group by, determined by the mode parameter
+            if (outputInspector == null)
+                outputInspector = udafComplete.init(mode, parameterInspectors);
+
+            // initial partial gby udaf
+            GenericUDAFEvaluator.Mode partialMode;
+            // adjust mode for external groupby
+            if (mode == GenericUDAFEvaluator.Mode.COMPLETE)
+                partialMode = GenericUDAFEvaluator.Mode.PARTIAL1;
+            else if (mode == GenericUDAFEvaluator.Mode.FINAL)
+                partialMode = GenericUDAFEvaluator.Mode.PARTIAL2;
+            else
+                partialMode = mode;
+            udafPartial = udafsPartial.get(threadId);
+            if (udafPartial == null) {
+                try {
+                    udafPartial = FunctionRegistry.getGenericUDAFEvaluator(genericUDAFName, oiListForTypes, distinct,
+                            false);
+                } catch (HiveException e) {
+                    throw new AlgebricksException(e);
+                }
+                udafPartial.init(partialMode, parameterInspectors);
+                udafsPartial.put(threadId, udafPartial);
+            }
+
+            // multiple stage group by, determined by the mode parameter
+            if (outputInspectorPartial == null)
+                outputInspectorPartial = udafPartial.init(partialMode, parameterInspectors);
+        } catch (Exception e) {
+            e.printStackTrace();
+            throw new AlgebricksException(e);
+        }
+
+        return new AggregationFunctionEvaluator(parameters, types, genericUDAFName, mode, distinct, rowInspector,
+                provider.getDataOutput(), evals, parameterInspectors, cachedParas, lazySer, cachedRowObject,
+                udafPartial, udafComplete, outputInspector, outputInspectorPartial);
+    }
+
+    public String toString() {
+        return "aggregation function expression evaluator factory: " + this.genericUDAFName;
+    }
+}
diff --git a/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/factory/evaluator/AggregationFunctionSerializableFactory.java b/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/factory/evaluator/AggregationFunctionSerializableFactory.java
index 71d11c0..c1ee814 100644
--- a/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/factory/evaluator/AggregationFunctionSerializableFactory.java
+++ b/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/factory/evaluator/AggregationFunctionSerializableFactory.java
@@ -39,12 +39,14 @@
 import edu.uci.ics.hivesterix.serde.lazy.LazyFactory;
 import edu.uci.ics.hivesterix.serde.lazy.LazyObject;
 import edu.uci.ics.hivesterix.serde.lazy.LazySerDe;
+import edu.uci.ics.hivesterix.serde.lazy.LazyUtils;
 import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
 import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.AggregateFunctionCallExpression;
 import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.IVariableTypeEnvironment;
 import edu.uci.ics.hyracks.algebricks.runtime.base.ICopySerializableAggregateFunction;
 import edu.uci.ics.hyracks.algebricks.runtime.base.ICopySerializableAggregateFunctionFactory;
 
+@SuppressWarnings("deprecation")
 public class AggregationFunctionSerializableFactory implements ICopySerializableAggregateFunctionFactory {
 
     private static final long serialVersionUID = 1L;
@@ -190,10 +192,19 @@
             String s = Utilities.serializeExpression(input);
             parametersSerialization.add(s);
         }
+
     }
 
     @Override
     public synchronized ICopySerializableAggregateFunction createAggregateFunction() throws AlgebricksException {
+        /**
+         * list of object inspectors correlated to types
+         */
+        List<ObjectInspector> oiListForTypes = new ArrayList<ObjectInspector>();
+        for (TypeInfo type : types) {
+            oiListForTypes.add(LazyUtils.getLazyObjectInspectorFromTypeInfo(type, false));
+        }
+
         if (parametersOrigin == null) {
             Configuration config = new Configuration();
             config.setClassLoader(this.getClass().getClassLoader());
@@ -328,7 +339,8 @@
             udafComplete = udafsComplete.get(threadId);
             if (udafComplete == null) {
                 try {
-                    udafComplete = FunctionRegistry.getGenericUDAFEvaluator(genericUDAFName, types, distinct, false);
+                    udafComplete = FunctionRegistry.getGenericUDAFEvaluator(genericUDAFName, oiListForTypes, distinct,
+                            false);
                 } catch (HiveException e) {
                     throw new AlgebricksException(e);
                 }
@@ -352,7 +364,8 @@
             udafPartial = udafsPartial.get(threadId);
             if (udafPartial == null) {
                 try {
-                    udafPartial = FunctionRegistry.getGenericUDAFEvaluator(genericUDAFName, types, distinct, false);
+                    udafPartial = FunctionRegistry.getGenericUDAFEvaluator(genericUDAFName, oiListForTypes, distinct,
+                            false);
                 } catch (HiveException e) {
                     throw new AlgebricksException(e);
                 }
diff --git a/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/operator/filescan/HiveKeyValueParser.java b/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/operator/filescan/HiveKeyValueParser.java
index 1bf4abe..833daf4 100644
--- a/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/operator/filescan/HiveKeyValueParser.java
+++ b/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/operator/filescan/HiveKeyValueParser.java
@@ -166,7 +166,7 @@
     }
 
     @Override
-    public void parse(K key, V value, IFrameWriter writer) throws HyracksDataException {
+    public void parse(K key, V value, IFrameWriter writer, String fileString) throws HyracksDataException {
         try {
             tb.reset();
             if (parser != null) {
diff --git a/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/operator/filewrite/HiveFileWritePushRuntime.java b/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/operator/filewrite/HiveFileWritePushRuntime.java
index e89a4c4..4bbb21f 100644
--- a/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/operator/filewrite/HiveFileWritePushRuntime.java
+++ b/hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/operator/filewrite/HiveFileWritePushRuntime.java
@@ -12,156 +12,176 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package edu.uci.ics.hivesterix.runtime.operator.filewrite;
-
-import java.nio.ByteBuffer;
-
-import org.apache.hadoop.hive.ql.exec.FileSinkOperator;
-import org.apache.hadoop.hive.ql.exec.OperatorFactory;
-import org.apache.hadoop.hive.ql.exec.RowSchema;
-import org.apache.hadoop.hive.ql.metadata.HiveException;
-import org.apache.hadoop.hive.ql.plan.FileSinkDesc;
-import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
-import org.apache.hadoop.mapred.JobConf;
-
-import edu.uci.ics.hivesterix.runtime.jobgen.Schema;
-import edu.uci.ics.hivesterix.serde.lazy.LazyColumnar;
-import edu.uci.ics.hivesterix.serde.lazy.objectinspector.LazyColumnarObjectInspector;
-import edu.uci.ics.hyracks.algebricks.runtime.base.IPushRuntime;
-import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
-import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAccessor;
-import edu.uci.ics.hyracks.dataflow.common.data.accessors.FrameTupleReference;
-
-@SuppressWarnings("deprecation")
-public class HiveFileWritePushRuntime implements IPushRuntime {
-
-	/**
-	 * frame tuple accessor to access byte buffer
-	 */
-	private final FrameTupleAccessor accessor;
-
-	/**
-	 * input object inspector
-	 */
-	private final ObjectInspector inputInspector;
-
-	/**
-	 * cachedInput
-	 */
-	private final LazyColumnar cachedInput;
-
-	/**
-	 * File sink operator of Hive
-	 */
-	private final FileSinkDesc fileSink;
-
-	/**
-	 * job configuration, which contain name node and other configuration
-	 * information
-	 */
-	private JobConf conf;
-
-	/**
-	 * input object inspector
-	 */
-	private final Schema inputSchema;
-
-	/**
-	 * a copy of hive schema representation
-	 */
-	private RowSchema rowSchema;
-
-	/**
-	 * the Hive file sink operator
-	 */
-	private FileSinkOperator fsOp;
-
-	/**
-	 * cached tuple object reference
-	 */
-	private FrameTupleReference tuple = new FrameTupleReference();
-
-	/**
-	 * @param spec
-	 * @param fsProvider
-	 */
-	public HiveFileWritePushRuntime(IHyracksTaskContext context,
-			RecordDescriptor inputRecordDesc, JobConf job, FileSinkDesc fs,
-			RowSchema schema, Schema oi) {
-		fileSink = fs;
-		fileSink.setGatherStats(false);
-
-		rowSchema = schema;
-		conf = job;
-		inputSchema = oi;
-
-		accessor = new FrameTupleAccessor(context.getFrameSize(),
-				inputRecordDesc);
-		inputInspector = inputSchema.toObjectInspector();
-		cachedInput = new LazyColumnar(
-				(LazyColumnarObjectInspector) inputInspector);
-	}
-
-	@Override
-	public void open() throws HyracksDataException {
-		fsOp = (FileSinkOperator) OperatorFactory.get(fileSink, rowSchema);
-		fsOp.setChildOperators(null);
-		fsOp.setParentOperators(null);
-		conf.setClassLoader(this.getClass().getClassLoader());
-
-		ObjectInspector[] inspectors = new ObjectInspector[1];
-		inspectors[0] = inputInspector;
-		try {
-			fsOp.initialize(conf, inspectors);
-			fsOp.setExecContext(null);
-		} catch (Exception e) {
-			e.printStackTrace();
-		}
-	}
-
-	@Override
-	public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
-		accessor.reset(buffer);
-		int n = accessor.getTupleCount();
-		try {
-			for (int i = 0; i < n; ++i) {
-				tuple.reset(accessor, i);
-				cachedInput.init(tuple);
-				fsOp.process(cachedInput, 0);
-			}
-		} catch (HiveException e) {
-			throw new HyracksDataException(e);
-		}
-	}
-
-	@Override
-	public void close() throws HyracksDataException {
-		try {
-			Thread.currentThread().setContextClassLoader(
-					this.getClass().getClassLoader());
-			fsOp.closeOp(false);
-		} catch (HiveException e) {
-			throw new HyracksDataException(e);
-		}
-	}
-
-	@Override
-	public void setFrameWriter(int index, IFrameWriter writer,
-			RecordDescriptor recordDesc) {
-		throw new IllegalStateException();
-	}
-
-	@Override
-	public void setInputRecordDescriptor(int index,
-			RecordDescriptor recordDescriptor) {
-	}
-
-	@Override
-	public void fail() throws HyracksDataException {
-
-	}
-
-}
+package edu.uci.ics.hivesterix.runtime.operator.filewrite;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.util.logging.Logger;
+
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hive.ql.exec.FileSinkOperator;
+import org.apache.hadoop.hive.ql.exec.OperatorFactory;
+import org.apache.hadoop.hive.ql.exec.RowSchema;
+import org.apache.hadoop.hive.ql.exec.Utilities;
+import org.apache.hadoop.hive.ql.metadata.HiveException;
+import org.apache.hadoop.hive.ql.plan.FileSinkDesc;
+import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
+import org.apache.hadoop.hive.shims.ShimLoader;
+import org.apache.hadoop.mapred.JobConf;
+
+import edu.uci.ics.hivesterix.runtime.jobgen.Schema;
+import edu.uci.ics.hivesterix.serde.lazy.LazyColumnar;
+import edu.uci.ics.hivesterix.serde.lazy.objectinspector.LazyColumnarObjectInspector;
+import edu.uci.ics.hyracks.algebricks.runtime.base.IPushRuntime;
+import edu.uci.ics.hyracks.api.comm.IFrameWriter;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAccessor;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.FrameTupleReference;
+
+@SuppressWarnings("deprecation")
+public class HiveFileWritePushRuntime implements IPushRuntime {
+    private final static Logger LOGGER = Logger.getLogger(HiveFileWritePushRuntime.class.getName());
+
+    /**
+     * frame tuple accessor to access byte buffer
+     */
+    private final FrameTupleAccessor accessor;
+
+    /**
+     * input object inspector
+     */
+    private final ObjectInspector inputInspector;
+
+    /**
+     * cachedInput
+     */
+    private final LazyColumnar cachedInput;
+
+    /**
+     * File sink operator of Hive
+     */
+    private final FileSinkDesc fileSink;
+
+    /**
+     * job configuration, which contain name node and other configuration
+     * information
+     */
+    private JobConf conf;
+
+    /**
+     * input object inspector
+     */
+    private final Schema inputSchema;
+
+    /**
+     * a copy of hive schema representation
+     */
+    private RowSchema rowSchema;
+
+    /**
+     * the Hive file sink operator
+     */
+    private FileSinkOperator fsOp;
+
+    /**
+     * cached tuple object reference
+     */
+    private FrameTupleReference tuple = new FrameTupleReference();
+
+    /**
+     * @param spec
+     * @param fsProvider
+     */
+    public HiveFileWritePushRuntime(IHyracksTaskContext context, RecordDescriptor inputRecordDesc, JobConf job,
+            FileSinkDesc fs, RowSchema schema, Schema oi) {
+        fileSink = fs;
+        fileSink.setGatherStats(false);
+
+        rowSchema = schema;
+        conf = job;
+        inputSchema = oi;
+
+        accessor = new FrameTupleAccessor(context.getFrameSize(), inputRecordDesc);
+        inputInspector = inputSchema.toObjectInspector();
+        cachedInput = new LazyColumnar((LazyColumnarObjectInspector) inputInspector);
+    }
+
+    @Override
+    public void open() throws HyracksDataException {
+        fsOp = (FileSinkOperator) OperatorFactory.get(fileSink, rowSchema);
+        fsOp.setChildOperators(null);
+        fsOp.setParentOperators(null);
+        conf.setClassLoader(this.getClass().getClassLoader());
+
+        ObjectInspector[] inspectors = new ObjectInspector[1];
+        inspectors[0] = inputInspector;
+        try {
+            fsOp.initialize(conf, inspectors);
+            fsOp.setExecContext(null);
+            createTempDir();
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+
+    @Override
+    public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
+        accessor.reset(buffer);
+        int n = accessor.getTupleCount();
+        try {
+            for (int i = 0; i < n; ++i) {
+                tuple.reset(accessor, i);
+                cachedInput.init(tuple);
+                fsOp.process(cachedInput, 0);
+            }
+        } catch (HiveException e) {
+            throw new HyracksDataException(e);
+        }
+    }
+
+    @Override
+    public void close() throws HyracksDataException {
+        try {
+            Thread.currentThread().setContextClassLoader(this.getClass().getClassLoader());
+            fsOp.closeOp(false);
+        } catch (HiveException e) {
+            throw new HyracksDataException(e);
+        }
+    }
+
+    @Override
+    public void setFrameWriter(int index, IFrameWriter writer, RecordDescriptor recordDesc) {
+        throw new IllegalStateException();
+    }
+
+    @Override
+    public void setInputRecordDescriptor(int index, RecordDescriptor recordDescriptor) {
+    }
+
+    @Override
+    public void fail() throws HyracksDataException {
+
+    }
+
+    private void createTempDir() throws IOException {
+        FileSinkDesc fdesc = fsOp.getConf();
+        String tempDir = fdesc.getDirName();
+        if (tempDir != null) {
+            Path tempPath = Utilities.toTempPath(new Path(tempDir));
+            FileSystem fs = tempPath.getFileSystem(conf);
+            if (!fs.exists(tempPath)) {
+                try {
+                    fs.mkdirs(tempPath);
+                    ShimLoader.getHadoopShims().fileSystemDeleteOnExit(fs, tempPath);
+                } catch (IOException e) {
+                    //if the dir already exists, that should be fine; so log a warning msg
+                    LOGGER.warning("create tmp result directory fails.");
+                }
+            }
+        }
+    }
+
+}
diff --git a/hivesterix/hivesterix-serde/pom.xml b/hivesterix/hivesterix-serde/pom.xml
index 97c9174..b53661b 100644
--- a/hivesterix/hivesterix-serde/pom.xml
+++ b/hivesterix/hivesterix-serde/pom.xml
@@ -18,7 +18,7 @@
 	<parent>
 		<artifactId>hivesterix</artifactId>
 		<groupId>edu.uci.ics.hyracks</groupId>
-		<version>0.2.7-SNAPSHOT</version>
+		<version>0.2.10-SNAPSHOT</version>
 	</parent>
 
 	<artifactId>hivesterix-serde</artifactId>
@@ -42,37 +42,37 @@
 
 	<dependencies>
 		<dependency>
-			<groupId>org.apache.hadoop.hive</groupId>
+			<groupId>org.apache.hive</groupId>
 			<artifactId>hive-serde</artifactId>
-			<version>0.7.0</version>
+			<version>0.11.0</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
-			<groupId>org.apache.hadoop.hive</groupId>
+			<groupId>org.apache.hive</groupId>
 			<artifactId>hive-common</artifactId>
-			<version>0.7.0</version>
+			<version>0.11.0</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>algebricks-compiler</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
-                        <groupId>edu.uci.ics.hyracks</groupId>
-                        <artifactId>hivesterix-common</artifactId>
-                        <version>0.2.7-SNAPSHOT</version>
-                        <type>jar</type>
-                        <scope>compile</scope>
-                </dependency>
+			<groupId>edu.uci.ics.hyracks</groupId>
+			<artifactId>hyracks-hdfs-core</artifactId>
+			<version>0.2.10-SNAPSHOT</version>
+			<type>jar</type>
+			<scope>compile</scope>
+		</dependency>
 		<dependency>
 			<groupId>junit</groupId>
 			<artifactId>junit</artifactId>
-			<version>3.8.1</version>
+			<version>4.8.1</version>
 			<scope>test</scope>
 		</dependency>
 	</dependencies>
diff --git a/hivesterix/hivesterix-serde/src/main/java/edu/uci/ics/hivesterix/serde/lazy/LazySerDe.java b/hivesterix/hivesterix-serde/src/main/java/edu/uci/ics/hivesterix/serde/lazy/LazySerDe.java
index b5d64e8..2bbb1d5 100644
--- a/hivesterix/hivesterix-serde/src/main/java/edu/uci/ics/hivesterix/serde/lazy/LazySerDe.java
+++ b/hivesterix/hivesterix-serde/src/main/java/edu/uci/ics/hivesterix/serde/lazy/LazySerDe.java
@@ -46,6 +46,7 @@
 import org.apache.hadoop.hive.serde2.ByteStream.Output;
 import org.apache.hadoop.hive.serde2.SerDe;
 import org.apache.hadoop.hive.serde2.SerDeException;
+import org.apache.hadoop.hive.serde2.SerDeStats;
 import org.apache.hadoop.hive.serde2.objectinspector.ListObjectInspector;
 import org.apache.hadoop.hive.serde2.objectinspector.MapObjectInspector;
 import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
@@ -74,6 +75,7 @@
  * deserialized until required. Binary means a field is serialized in binary
  * compact format.
  */
+@SuppressWarnings("deprecation")
 public class LazySerDe implements SerDe {
 
     public static final Log LOG = LogFactory.getLog(LazySerDe.class.getName());
@@ -140,7 +142,6 @@
     /**
      * Deserialize a table record to a Lazy struct.
      */
-    @SuppressWarnings("deprecation")
     @Override
     public Object deserialize(Writable field) throws SerDeException {
         if (byteArrayRef == null) {
@@ -471,4 +472,9 @@
             }
         }
     }
+
+	@Override
+	public SerDeStats getSerDeStats() {
+		return null;
+	}
 }
diff --git a/hivesterix/hivesterix-translator/pom.xml b/hivesterix/hivesterix-translator/pom.xml
index 8a24d5e..d8c205f 100644
--- a/hivesterix/hivesterix-translator/pom.xml
+++ b/hivesterix/hivesterix-translator/pom.xml
@@ -21,7 +21,7 @@
 	<parent>
 		<artifactId>hivesterix</artifactId>
 		<groupId>edu.uci.ics.hyracks</groupId>
-		<version>0.2.7-SNAPSHOT</version>
+		<version>0.2.10-SNAPSHOT</version>
 	</parent>
 
 	<build>
@@ -42,30 +42,23 @@
 
 	<dependencies>
 		<dependency>
-			<groupId>org.apache.hadoop.hive</groupId>
-			<artifactId>hive-exec</artifactId>
-			<version>0.7.0</version>
-			<type>jar</type>
-			<scope>compile</scope>
-		</dependency>
-		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>algebricks-compiler</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hivesterix-common</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hivesterix-runtime</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
diff --git a/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/HiveAlgebricksTranslator.java b/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/HiveAlgebricksTranslator.java
index f32d85b..76cc51d 100644
--- a/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/HiveAlgebricksTranslator.java
+++ b/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/HiveAlgebricksTranslator.java
@@ -12,810 +12,809 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package edu.uci.ics.hivesterix.logical.plan;
-
-import java.io.OutputStreamWriter;
-import java.io.PrintWriter;
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Map.Entry;
-import java.util.Set;
-
-import org.apache.commons.lang3.mutable.Mutable;
-import org.apache.commons.lang3.mutable.MutableObject;
-import org.apache.hadoop.hive.ql.exec.ColumnInfo;
-import org.apache.hadoop.hive.ql.exec.ExtractOperator;
-import org.apache.hadoop.hive.ql.exec.FileSinkOperator;
-import org.apache.hadoop.hive.ql.exec.FilterOperator;
-import org.apache.hadoop.hive.ql.exec.GroupByOperator;
-import org.apache.hadoop.hive.ql.exec.JoinOperator;
-import org.apache.hadoop.hive.ql.exec.LateralViewJoinOperator;
-import org.apache.hadoop.hive.ql.exec.LimitOperator;
-import org.apache.hadoop.hive.ql.exec.MapJoinOperator;
-import org.apache.hadoop.hive.ql.exec.Operator;
-import org.apache.hadoop.hive.ql.exec.ReduceSinkOperator;
-import org.apache.hadoop.hive.ql.exec.SelectOperator;
-import org.apache.hadoop.hive.ql.exec.TableScanOperator;
-import org.apache.hadoop.hive.ql.exec.UDF;
-import org.apache.hadoop.hive.ql.exec.UDTFOperator;
-import org.apache.hadoop.hive.ql.exec.UnionOperator;
-import org.apache.hadoop.hive.ql.plan.AggregationDesc;
-import org.apache.hadoop.hive.ql.plan.ExprNodeColumnDesc;
-import org.apache.hadoop.hive.ql.plan.ExprNodeConstantDesc;
-import org.apache.hadoop.hive.ql.plan.ExprNodeDesc;
-import org.apache.hadoop.hive.ql.plan.ExprNodeFieldDesc;
-import org.apache.hadoop.hive.ql.plan.ExprNodeGenericFuncDesc;
-import org.apache.hadoop.hive.ql.plan.ExprNodeNullDesc;
-import org.apache.hadoop.hive.ql.plan.PartitionDesc;
-import org.apache.hadoop.hive.ql.plan.UDTFDesc;
-import org.apache.hadoop.hive.ql.plan.api.OperatorType;
-import org.apache.hadoop.hive.ql.udf.generic.GenericUDF;
-import org.apache.hadoop.hive.ql.udf.generic.GenericUDFBridge;
-import org.apache.hadoop.hive.serde2.typeinfo.TypeInfo;
-
-import edu.uci.ics.hivesterix.logical.expression.ExpressionConstant;
-import edu.uci.ics.hivesterix.logical.expression.HiveAlgebricksBuiltInFunctionMap;
-import edu.uci.ics.hivesterix.logical.expression.HiveFunctionInfo;
-import edu.uci.ics.hivesterix.logical.expression.HivesterixConstantValue;
-import edu.uci.ics.hivesterix.logical.plan.visitor.ExtractVisitor;
-import edu.uci.ics.hivesterix.logical.plan.visitor.FilterVisitor;
-import edu.uci.ics.hivesterix.logical.plan.visitor.GroupByVisitor;
-import edu.uci.ics.hivesterix.logical.plan.visitor.JoinVisitor;
-import edu.uci.ics.hivesterix.logical.plan.visitor.LateralViewJoinVisitor;
-import edu.uci.ics.hivesterix.logical.plan.visitor.LimitVisitor;
-import edu.uci.ics.hivesterix.logical.plan.visitor.MapJoinVisitor;
-import edu.uci.ics.hivesterix.logical.plan.visitor.ProjectVisitor;
-import edu.uci.ics.hivesterix.logical.plan.visitor.SortVisitor;
-import edu.uci.ics.hivesterix.logical.plan.visitor.TableScanWriteVisitor;
-import edu.uci.ics.hivesterix.logical.plan.visitor.UnionVisitor;
-import edu.uci.ics.hivesterix.logical.plan.visitor.base.Translator;
-import edu.uci.ics.hivesterix.logical.plan.visitor.base.Visitor;
-import edu.uci.ics.hivesterix.runtime.jobgen.Schema;
-import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
-import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalExpression;
-import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalOperator;
-import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalPlan;
-import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalVariable;
-import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.AggregateFunctionCallExpression;
-import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.ConstantExpression;
-import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.ScalarFunctionCallExpression;
-import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.UnnestingFunctionCallExpression;
-import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.VariableReferenceExpression;
-import edu.uci.ics.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
-import edu.uci.ics.hyracks.algebricks.core.algebra.metadata.IMetadataProvider;
-import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.AssignOperator;
-import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.ReplicateOperator;
-import edu.uci.ics.hyracks.algebricks.core.algebra.plan.ALogicalPlanImpl;
-import edu.uci.ics.hyracks.algebricks.core.algebra.prettyprint.LogicalOperatorPrettyPrintVisitor;
-import edu.uci.ics.hyracks.algebricks.core.algebra.prettyprint.PlanPrettyPrinter;
-
-@SuppressWarnings("rawtypes")
-public class HiveAlgebricksTranslator implements Translator {
-
-    private int currentVariable = 0;
-
-    private List<Mutable<ILogicalOperator>> logicalOp = new ArrayList<Mutable<ILogicalOperator>>();
-
-    private boolean continueTraverse = true;
-
-    private IMetadataProvider<PartitionDesc, Object> metaData;
-
-    /**
-     * map variable name to the logical variable
-     */
-    private HashMap<String, LogicalVariable> nameToLogicalVariableMap = new HashMap<String, LogicalVariable>();
-
-    /**
-     * map field name to LogicalVariable
-     */
-    private HashMap<String, LogicalVariable> fieldToLogicalVariableMap = new HashMap<String, LogicalVariable>();
-
-    /**
-     * map logical variable to name
-     */
-    private HashMap<LogicalVariable, String> logicalVariableToFieldMap = new HashMap<LogicalVariable, String>();
-
-    /**
-     * asterix root operators
-     */
-    private List<Mutable<ILogicalOperator>> rootOperators = new ArrayList<Mutable<ILogicalOperator>>();
-
-    /**
-     * a list of visitors
-     */
-    private List<Visitor> visitors = new ArrayList<Visitor>();
-
-    /**
-     * output writer to print things out
-     */
-    private static PrintWriter outputWriter = new PrintWriter(new OutputStreamWriter(System.out));
-
-    /**
-     * map a logical variable to type info
-     */
-    private HashMap<LogicalVariable, TypeInfo> variableToType = new HashMap<LogicalVariable, TypeInfo>();
-
-    @Override
-    public LogicalVariable getVariable(String fieldName, TypeInfo type) {
-        LogicalVariable var = fieldToLogicalVariableMap.get(fieldName);
-        if (var == null) {
-            currentVariable++;
-            var = new LogicalVariable(currentVariable);
-            fieldToLogicalVariableMap.put(fieldName, var);
-            nameToLogicalVariableMap.put(var.toString(), var);
-            variableToType.put(var, type);
-            logicalVariableToFieldMap.put(var, fieldName);
-        }
-        return var;
-    }
-
-    @Override
-    public LogicalVariable getNewVariable(String fieldName, TypeInfo type) {
-        currentVariable++;
-        LogicalVariable var = new LogicalVariable(currentVariable);
-        fieldToLogicalVariableMap.put(fieldName, var);
-        nameToLogicalVariableMap.put(var.toString(), var);
-        variableToType.put(var, type);
-        logicalVariableToFieldMap.put(var, fieldName);
-        return var;
-    }
-
-    @Override
-    public void replaceVariable(LogicalVariable oldVar, LogicalVariable newVar) {
-        String name = this.logicalVariableToFieldMap.get(oldVar);
-        if (name != null) {
-            fieldToLogicalVariableMap.put(name, newVar);
-            nameToLogicalVariableMap.put(newVar.toString(), newVar);
-            nameToLogicalVariableMap.put(oldVar.toString(), newVar);
-            logicalVariableToFieldMap.put(newVar, name);
-        }
-    }
-
-    @Override
-    public IMetadataProvider<PartitionDesc, Object> getMetadataProvider() {
-        return metaData;
-    }
-
-    /**
-     * only get an variable, without rewriting it
-     * 
-     * @param fieldName
-     * @return
-     */
-    private LogicalVariable getVariableOnly(String fieldName) {
-        return fieldToLogicalVariableMap.get(fieldName);
-    }
-
-    private void updateVariable(String fieldName, LogicalVariable variable) {
-        LogicalVariable var = fieldToLogicalVariableMap.get(fieldName);
-        if (var == null) {
-            fieldToLogicalVariableMap.put(fieldName, variable);
-            nameToLogicalVariableMap.put(fieldName, variable);
-        } else if (!var.equals(variable)) {
-            fieldToLogicalVariableMap.put(fieldName, variable);
-            nameToLogicalVariableMap.put(fieldName, variable);
-        }
-    }
-
-    /**
-     * get a list of logical variables from the schema
-     * 
-     * @param schema
-     * @return
-     */
-    @Override
-    public List<LogicalVariable> getVariablesFromSchema(Schema schema) {
-        List<LogicalVariable> variables = new ArrayList<LogicalVariable>();
-        List<String> names = schema.getNames();
-
-        for (String name : names)
-            variables.add(nameToLogicalVariableMap.get(name));
-        return variables;
-    }
-
-    /**
-     * get variable to typeinfo map
-     * 
-     * @return
-     */
-    public HashMap<LogicalVariable, TypeInfo> getVariableContext() {
-        return this.variableToType;
-    }
-
-    /**
-     * get the number of variables s
-     * 
-     * @return
-     */
-    public int getVariableCounter() {
-        return currentVariable + 1;
-    }
-
-    /**
-     * translate from hive operator tree to asterix operator tree
-     * 
-     * @param hive
-     *            roots
-     * @return Algebricks roots
-     */
-    public void translate(List<Operator> hiveRoot, ILogicalOperator parentOperator,
-            HashMap<String, PartitionDesc> aliasToPathMap) throws AlgebricksException {
-        /**
-         * register visitors
-         */
-        visitors.add(new FilterVisitor());
-        visitors.add(new GroupByVisitor());
-        visitors.add(new JoinVisitor());
-        visitors.add(new LateralViewJoinVisitor());
-        visitors.add(new UnionVisitor());
-        visitors.add(new LimitVisitor());
-        visitors.add(new MapJoinVisitor());
-        visitors.add(new ProjectVisitor());
-        visitors.add(new SortVisitor());
-        visitors.add(new ExtractVisitor());
-        visitors.add(new TableScanWriteVisitor(aliasToPathMap));
-
-        List<Mutable<ILogicalOperator>> refList = translate(hiveRoot, new MutableObject<ILogicalOperator>(
-                parentOperator));
-        insertReplicateOperator(refList);
-        if (refList != null)
-            rootOperators.addAll(refList);
-    }
-
-    /**
-     * translate operator DAG
-     * 
-     * @param hiveRoot
-     * @param AlgebricksParentOperator
-     * @return
-     */
-    private List<Mutable<ILogicalOperator>> translate(List<Operator> hiveRoot,
-            Mutable<ILogicalOperator> AlgebricksParentOperator) throws AlgebricksException {
-
-        for (Operator hiveOperator : hiveRoot) {
-            continueTraverse = true;
-            Mutable<ILogicalOperator> currentOperatorRef = null;
-            if (hiveOperator.getType() == OperatorType.FILTER) {
-                FilterOperator fop = (FilterOperator) hiveOperator;
-                for (Visitor visitor : visitors) {
-                    currentOperatorRef = visitor.visit(fop, AlgebricksParentOperator, this);
-                    if (currentOperatorRef != null)
-                        break;
-                }
-            } else if (hiveOperator.getType() == OperatorType.REDUCESINK) {
-                ReduceSinkOperator fop = (ReduceSinkOperator) hiveOperator;
-                for (Visitor visitor : visitors) {
-                    currentOperatorRef = visitor.visit(fop, AlgebricksParentOperator, this);
-                    if (currentOperatorRef != null)
-                        break;
-                }
-            } else if (hiveOperator.getType() == OperatorType.JOIN) {
-                JoinOperator fop = (JoinOperator) hiveOperator;
-                for (Visitor visitor : visitors) {
-                    currentOperatorRef = visitor.visit(fop, AlgebricksParentOperator, this);
-                    if (currentOperatorRef != null) {
-                        continueTraverse = true;
-                        break;
-                    } else
-                        continueTraverse = false;
-                }
-                if (currentOperatorRef == null)
-                    return null;
-            } else if (hiveOperator.getType() == OperatorType.LATERALVIEWJOIN) {
-                LateralViewJoinOperator fop = (LateralViewJoinOperator) hiveOperator;
-                for (Visitor visitor : visitors) {
-                    currentOperatorRef = visitor.visit(fop, AlgebricksParentOperator, this);
-                    if (currentOperatorRef != null)
-                        break;
-                }
-                if (currentOperatorRef == null)
-                    return null;
-            } else if (hiveOperator.getType() == OperatorType.MAPJOIN) {
-                MapJoinOperator fop = (MapJoinOperator) hiveOperator;
-                for (Visitor visitor : visitors) {
-                    currentOperatorRef = visitor.visit(fop, AlgebricksParentOperator, this);
-                    if (currentOperatorRef != null) {
-                        continueTraverse = true;
-                        break;
-                    } else
-                        continueTraverse = false;
-                }
-                if (currentOperatorRef == null)
-                    return null;
-            } else if (hiveOperator.getType() == OperatorType.SELECT) {
-                SelectOperator fop = (SelectOperator) hiveOperator;
-                for (Visitor visitor : visitors) {
-                    currentOperatorRef = visitor.visit(fop, AlgebricksParentOperator, this);
-                    if (currentOperatorRef != null)
-                        break;
-                }
-            } else if (hiveOperator.getType() == OperatorType.EXTRACT) {
-                ExtractOperator fop = (ExtractOperator) hiveOperator;
-                for (Visitor visitor : visitors) {
-                    currentOperatorRef = visitor.visit(fop, AlgebricksParentOperator, this);
-                    if (currentOperatorRef != null)
-                        break;
-                }
-            } else if (hiveOperator.getType() == OperatorType.GROUPBY) {
-                GroupByOperator fop = (GroupByOperator) hiveOperator;
-                for (Visitor visitor : visitors) {
-                    currentOperatorRef = visitor.visit(fop, AlgebricksParentOperator, this);
-                    if (currentOperatorRef != null)
-                        break;
-                }
-            } else if (hiveOperator.getType() == OperatorType.TABLESCAN) {
-                TableScanOperator fop = (TableScanOperator) hiveOperator;
-                for (Visitor visitor : visitors) {
-                    currentOperatorRef = visitor.visit(fop, AlgebricksParentOperator, this);
-                    if (currentOperatorRef != null)
-                        break;
-                }
-            } else if (hiveOperator.getType() == OperatorType.FILESINK) {
-                FileSinkOperator fop = (FileSinkOperator) hiveOperator;
-                for (Visitor visitor : visitors) {
-                    currentOperatorRef = visitor.visit(fop, AlgebricksParentOperator, this);
-                    if (currentOperatorRef != null)
-                        break;
-                }
-            } else if (hiveOperator.getType() == OperatorType.LIMIT) {
-                LimitOperator lop = (LimitOperator) hiveOperator;
-                for (Visitor visitor : visitors) {
-                    currentOperatorRef = visitor.visit(lop, AlgebricksParentOperator, this);
-                    if (currentOperatorRef != null)
-                        break;
-                }
-            } else if (hiveOperator.getType() == OperatorType.UDTF) {
-                UDTFOperator lop = (UDTFOperator) hiveOperator;
-                for (Visitor visitor : visitors) {
-                    currentOperatorRef = visitor.visit(lop, AlgebricksParentOperator, this);
-                    if (currentOperatorRef != null)
-                        break;
-                }
-            } else if (hiveOperator.getType() == OperatorType.UNION) {
-                UnionOperator lop = (UnionOperator) hiveOperator;
-                for (Visitor visitor : visitors) {
-                    currentOperatorRef = visitor.visit(lop, AlgebricksParentOperator, this);
-                    if (currentOperatorRef != null) {
-                        continueTraverse = true;
-                        break;
-                    } else
-                        continueTraverse = false;
-                }
-            } else
-                ;
-            if (hiveOperator.getChildOperators() != null && hiveOperator.getChildOperators().size() > 0
-                    && continueTraverse) {
-                @SuppressWarnings("unchecked")
-                List<Operator> children = hiveOperator.getChildOperators();
-                if (currentOperatorRef == null)
-                    currentOperatorRef = AlgebricksParentOperator;
-                translate(children, currentOperatorRef);
-            }
-            if (hiveOperator.getChildOperators() == null || hiveOperator.getChildOperators().size() == 0)
-                logicalOp.add(currentOperatorRef);
-        }
-        return logicalOp;
-    }
-
-    /**
-     * used in select, group by to get no-column-expression columns
-     * 
-     * @param cols
-     * @return
-     */
-    public ILogicalOperator getAssignOperator(Mutable<ILogicalOperator> parent, List<ExprNodeDesc> cols,
-            ArrayList<LogicalVariable> variables) {
-
-        ArrayList<Mutable<ILogicalExpression>> expressions = new ArrayList<Mutable<ILogicalExpression>>();
-
-        /**
-         * variables to be appended in the assign operator
-         */
-        ArrayList<LogicalVariable> appendedVariables = new ArrayList<LogicalVariable>();
-
-        // one variable can only be assigned once
-        for (ExprNodeDesc hiveExpr : cols) {
-            rewriteExpression(hiveExpr);
-
-            if (hiveExpr instanceof ExprNodeColumnDesc) {
-                ExprNodeColumnDesc desc2 = (ExprNodeColumnDesc) hiveExpr;
-                String fieldName = desc2.getTabAlias() + "." + desc2.getColumn();
-
-                // System.out.println("project expr: " + fieldName);
-
-                if (fieldName.indexOf("$$") < 0) {
-                    LogicalVariable var = getVariable(fieldName, hiveExpr.getTypeInfo());
-                    desc2.setColumn(var.toString());
-                    desc2.setTabAlias("");
-                    variables.add(var);
-                } else {
-                    LogicalVariable var = nameToLogicalVariableMap.get(desc2.getColumn());
-                    String name = this.logicalVariableToFieldMap.get(var);
-                    var = this.getVariableOnly(name);
-                    variables.add(var);
-                }
-            } else {
-                Mutable<ILogicalExpression> asterixExpr = translateScalarFucntion(hiveExpr);
-                expressions.add(asterixExpr);
-                LogicalVariable var = getVariable(hiveExpr.getExprString() + asterixExpr.hashCode(),
-                        hiveExpr.getTypeInfo());
-                variables.add(var);
-                appendedVariables.add(var);
-            }
-        }
-
-        /**
-         * create an assign operator to deal with appending
-         */
-        ILogicalOperator assignOp = null;
-        if (appendedVariables.size() > 0) {
-            assignOp = new AssignOperator(appendedVariables, expressions);
-            assignOp.getInputs().add(parent);
-        }
-        return assignOp;
-    }
-
-    private ILogicalPlan plan;
-
-    public ILogicalPlan genLogicalPlan() {
-        plan = new ALogicalPlanImpl(rootOperators);
-        return plan;
-    }
-
-    public void printOperators() throws AlgebricksException {
-        LogicalOperatorPrettyPrintVisitor pvisitor = new LogicalOperatorPrettyPrintVisitor();
-        StringBuilder buffer = new StringBuilder();
-        PlanPrettyPrinter.printPlan(plan, buffer, pvisitor, 0);
-        outputWriter.println(buffer);
-        outputWriter.println("rewritten variables: ");
-        outputWriter.flush();
-        printVariables();
-
-    }
-
-    public static void setOutputPrinter(PrintWriter writer) {
-        outputWriter = writer;
-    }
-
-    private void printVariables() {
-        Set<Entry<String, LogicalVariable>> entries = fieldToLogicalVariableMap.entrySet();
-
-        for (Entry<String, LogicalVariable> entry : entries) {
-            outputWriter.println(entry.getKey() + " -> " + entry.getValue());
-        }
-        outputWriter.flush();
-    }
-
-    /**
-     * generate the object inspector for the output of an operator
-     * 
-     * @param operator
-     *            The Hive operator
-     * @return an ObjectInspector object
-     */
-    public Schema generateInputSchema(Operator operator) {
-        List<String> variableNames = new ArrayList<String>();
-        List<TypeInfo> typeList = new ArrayList<TypeInfo>();
-        List<ColumnInfo> columns = operator.getSchema().getSignature();
-
-        for (ColumnInfo col : columns) {
-            // typeList.add();
-            TypeInfo type = col.getType();
-            typeList.add(type);
-
-            String fieldName = col.getInternalName();
-            variableNames.add(fieldName);
-        }
-
-        return new Schema(variableNames, typeList);
-    }
-
-    /**
-     * rewrite the names of output columns for feature expression evaluators to
-     * use
-     * 
-     * @param operator
-     */
-    public void rewriteOperatorOutputSchema(Operator operator) {
-        List<ColumnInfo> columns = operator.getSchema().getSignature();
-
-        for (ColumnInfo column : columns) {
-            String columnName = column.getTabAlias() + "." + column.getInternalName();
-            if (columnName.indexOf("$$") < 0) {
-                LogicalVariable var = getVariable(columnName, column.getType());
-                column.setInternalName(var.toString());
-            }
-        }
-    }
-
-    @Override
-    public void rewriteOperatorOutputSchema(List<LogicalVariable> variables, Operator operator) {
-
-        //printOperatorSchema(operator);
-        List<ColumnInfo> columns = operator.getSchema().getSignature();
-        if (variables.size() != columns.size()) {
-            throw new IllegalStateException("output cardinality error " + operator.getName() + " variable size: "
-                    + variables.size() + " expected " + columns.size());
-        }
-
-        for (int i = 0; i < variables.size(); i++) {
-            LogicalVariable var = variables.get(i);
-            ColumnInfo column = columns.get(i);
-            String fieldName = column.getTabAlias() + "." + column.getInternalName();
-            if (fieldName.indexOf("$$") < 0) {
-                updateVariable(fieldName, var);
-                column.setInternalName(var.toString());
-            }
-        }
-        //printOperatorSchema(operator);
-    }
-
-    /**
-     * rewrite an expression and substitute variables
-     * 
-     * @param expr
-     *            hive expression
-     */
-    public void rewriteExpression(ExprNodeDesc expr) {
-        if (expr instanceof ExprNodeColumnDesc) {
-            ExprNodeColumnDesc desc = (ExprNodeColumnDesc) expr;
-            String fieldName = desc.getTabAlias() + "." + desc.getColumn();
-            if (fieldName.indexOf("$$") < 0) {
-                LogicalVariable var = getVariableOnly(fieldName);
-                if (var == null) {
-                    fieldName = "." + desc.getColumn();
-                    var = getVariableOnly(fieldName);
-                    if (var == null) {
-                        fieldName = "null." + desc.getColumn();
-                        var = getVariableOnly(fieldName);
-                        if (var == null) {
-                            throw new IllegalStateException(fieldName + " is wrong!!! ");
-                        }
-                    }
-                }
-                String name = this.logicalVariableToFieldMap.get(var);
-                var = getVariableOnly(name);
-                desc.setColumn(var.toString());
-            }
-        } else {
-            if (expr.getChildren() != null && expr.getChildren().size() > 0) {
-                List<ExprNodeDesc> children = expr.getChildren();
-                for (ExprNodeDesc desc : children)
-                    rewriteExpression(desc);
-            }
-        }
-    }
-
-    /**
-     * rewrite an expression and substitute variables
-     * 
-     * @param expr
-     *            hive expression
-     */
-    public void rewriteExpressionPartial(ExprNodeDesc expr) {
-        if (expr instanceof ExprNodeColumnDesc) {
-            ExprNodeColumnDesc desc = (ExprNodeColumnDesc) expr;
-            String fieldName = desc.getTabAlias() + "." + desc.getColumn();
-            if (fieldName.indexOf("$$") < 0) {
-                LogicalVariable var = getVariableOnly(fieldName);
-                desc.setColumn(var.toString());
-            }
-        } else {
-            if (expr.getChildren() != null && expr.getChildren().size() > 0) {
-                List<ExprNodeDesc> children = expr.getChildren();
-                for (ExprNodeDesc desc : children)
-                    rewriteExpressionPartial(desc);
-            }
-        }
-    }
-
-    // private void printOperatorSchema(Operator operator) {
-    // // System.out.println(operator.getName());
-    // // List<ColumnInfo> columns = operator.getSchema().getSignature();
-    // // for (ColumnInfo column : columns) {
-    // // System.out.print(column.getTabAlias() + "." +
-    // // column.getInternalName() + "  ");
-    // // }
-    // // System.out.println();
-    // }
-
-    /**
-     * translate scalar function expression
-     * 
-     * @param hiveExpr
-     * @return
-     */
-    public Mutable<ILogicalExpression> translateScalarFucntion(ExprNodeDesc hiveExpr) {
-        ILogicalExpression AlgebricksExpr;
-
-        if (hiveExpr instanceof ExprNodeGenericFuncDesc) {
-            List<Mutable<ILogicalExpression>> arguments = new ArrayList<Mutable<ILogicalExpression>>();
-            List<ExprNodeDesc> children = hiveExpr.getChildren();
-
-            for (ExprNodeDesc child : children)
-                arguments.add(translateScalarFucntion(child));
-
-            ExprNodeGenericFuncDesc funcExpr = (ExprNodeGenericFuncDesc) hiveExpr;
-            GenericUDF genericUdf = funcExpr.getGenericUDF();
-            UDF udf = null;
-            if (genericUdf instanceof GenericUDFBridge) {
-                GenericUDFBridge bridge = (GenericUDFBridge) genericUdf;
-                try {
-                    udf = bridge.getUdfClass().newInstance();
-                } catch (Exception e) {
-                    e.printStackTrace();
-                }
-            }
-
-            /**
-             * set up the hive function
-             */
-            Object hiveFunction = genericUdf;
-            if (udf != null)
-                hiveFunction = udf;
-
-            FunctionIdentifier funcId = HiveAlgebricksBuiltInFunctionMap.INSTANCE.getAlgebricksFunctionId(hiveFunction
-                    .getClass());
-            if (funcId == null) {
-                funcId = new FunctionIdentifier(ExpressionConstant.NAMESPACE, hiveFunction.getClass().getName());
-            }
-
-            Object functionInfo = null;
-            if (genericUdf instanceof GenericUDFBridge) {
-                functionInfo = funcExpr;
-            }
-
-            /**
-             * generate the function call expression
-             */
-            ScalarFunctionCallExpression AlgebricksFuncExpr = new ScalarFunctionCallExpression(new HiveFunctionInfo(
-                    funcId, functionInfo), arguments);
-            AlgebricksExpr = AlgebricksFuncExpr;
-
-        } else if (hiveExpr instanceof ExprNodeColumnDesc) {
-            ExprNodeColumnDesc column = (ExprNodeColumnDesc) hiveExpr;
-            LogicalVariable var = this.getVariable(column.getColumn());
-            AlgebricksExpr = new VariableReferenceExpression(var);
-
-        } else if (hiveExpr instanceof ExprNodeFieldDesc) {
-            FunctionIdentifier funcId;
-            funcId = new FunctionIdentifier(ExpressionConstant.NAMESPACE, ExpressionConstant.FIELDACCESS);
-
-            ScalarFunctionCallExpression AlgebricksFuncExpr = new ScalarFunctionCallExpression(new HiveFunctionInfo(
-                    funcId, hiveExpr));
-            AlgebricksExpr = AlgebricksFuncExpr;
-        } else if (hiveExpr instanceof ExprNodeConstantDesc) {
-            ExprNodeConstantDesc hiveConst = (ExprNodeConstantDesc) hiveExpr;
-            Object value = hiveConst.getValue();
-            AlgebricksExpr = new ConstantExpression(new HivesterixConstantValue(value));
-        } else if (hiveExpr instanceof ExprNodeNullDesc) {
-            FunctionIdentifier funcId;
-            funcId = new FunctionIdentifier(ExpressionConstant.NAMESPACE, ExpressionConstant.NULL);
-
-            ScalarFunctionCallExpression AlgebricksFuncExpr = new ScalarFunctionCallExpression(new HiveFunctionInfo(
-                    funcId, hiveExpr));
-
-            AlgebricksExpr = AlgebricksFuncExpr;
-        } else {
-            throw new IllegalStateException("unknown hive expression");
-        }
-        return new MutableObject<ILogicalExpression>(AlgebricksExpr);
-    }
-
-    /**
-     * translate aggregation function expression
-     * 
-     * @param aggregateDesc
-     * @return
-     */
-    public Mutable<ILogicalExpression> translateAggregation(AggregationDesc aggregateDesc) {
-
-        String UDAFName = aggregateDesc.getGenericUDAFName();
-
-        List<Mutable<ILogicalExpression>> arguments = new ArrayList<Mutable<ILogicalExpression>>();
-        List<ExprNodeDesc> children = aggregateDesc.getParameters();
-
-        for (ExprNodeDesc child : children)
-            arguments.add(translateScalarFucntion(child));
-
-        FunctionIdentifier funcId = new FunctionIdentifier(ExpressionConstant.NAMESPACE, UDAFName + "("
-                + aggregateDesc.getMode() + ")");
-        HiveFunctionInfo funcInfo = new HiveFunctionInfo(funcId, aggregateDesc);
-        AggregateFunctionCallExpression aggregationExpression = new AggregateFunctionCallExpression(funcInfo, false,
-                arguments);
-        return new MutableObject<ILogicalExpression>(aggregationExpression);
-    }
-
-    /**
-     * translate aggregation function expression
-     * 
-     * @param aggregator
-     * @return
-     */
-    public Mutable<ILogicalExpression> translateUnnestFunction(UDTFDesc udtfDesc, Mutable<ILogicalExpression> argument) {
-
-        String UDTFName = udtfDesc.getUDTFName();
-
-        FunctionIdentifier funcId = new FunctionIdentifier(ExpressionConstant.NAMESPACE, UDTFName);
-        UnnestingFunctionCallExpression unnestingExpression = new UnnestingFunctionCallExpression(new HiveFunctionInfo(
-                funcId, udtfDesc));
-        unnestingExpression.getArguments().add(argument);
-        return new MutableObject<ILogicalExpression>(unnestingExpression);
-    }
-
-    /**
-     * get typeinfo
-     */
-    @Override
-    public TypeInfo getType(LogicalVariable var) {
-        return variableToType.get(var);
-    }
-
-    /**
-     * get variable from variable name
-     */
-    @Override
-    public LogicalVariable getVariable(String name) {
-        return nameToLogicalVariableMap.get(name);
-    }
-
-    @Override
-    public LogicalVariable getVariableFromFieldName(String fieldName) {
-        return this.getVariableOnly(fieldName);
-    }
-
-    /**
-     * set the metadata provider
-     */
-    @Override
-    public void setMetadataProvider(IMetadataProvider<PartitionDesc, Object> metadata) {
-        this.metaData = metadata;
-    }
-
-    /**
-     * insert ReplicateOperator when necessary
-     */
-    private void insertReplicateOperator(List<Mutable<ILogicalOperator>> roots) {
-        Map<Mutable<ILogicalOperator>, List<Mutable<ILogicalOperator>>> childToParentsMap = new HashMap<Mutable<ILogicalOperator>, List<Mutable<ILogicalOperator>>>();
-        buildChildToParentsMapping(roots, childToParentsMap);
-        for (Entry<Mutable<ILogicalOperator>, List<Mutable<ILogicalOperator>>> entry : childToParentsMap.entrySet()) {
-            List<Mutable<ILogicalOperator>> pList = entry.getValue();
-            if (pList.size() > 1) {
-                ILogicalOperator rop = new ReplicateOperator(pList.size());
-                Mutable<ILogicalOperator> ropRef = new MutableObject<ILogicalOperator>(rop);
-                Mutable<ILogicalOperator> childRef = entry.getKey();
-                rop.getInputs().add(childRef);
-                for (Mutable<ILogicalOperator> parentRef : pList) {
-                    ILogicalOperator parentOp = parentRef.getValue();
-                    int index = parentOp.getInputs().indexOf(childRef);
-                    parentOp.getInputs().set(index, ropRef);
-                }
-            }
-        }
-    }
-
-    /**
-     * build the mapping from child to Parents
-     * 
-     * @param roots
-     * @param childToParentsMap
-     */
-    private void buildChildToParentsMapping(List<Mutable<ILogicalOperator>> roots,
-            Map<Mutable<ILogicalOperator>, List<Mutable<ILogicalOperator>>> map) {
-        for (Mutable<ILogicalOperator> opRef : roots) {
-            List<Mutable<ILogicalOperator>> childRefs = opRef.getValue().getInputs();
-            for (Mutable<ILogicalOperator> childRef : childRefs) {
-                List<Mutable<ILogicalOperator>> parentList = map.get(childRef);
-                if (parentList == null) {
-                    parentList = new ArrayList<Mutable<ILogicalOperator>>();
-                    map.put(childRef, parentList);
-                }
-                if (!parentList.contains(opRef))
-                    parentList.add(opRef);
-            }
-            buildChildToParentsMapping(childRefs, map);
-        }
-    }
-}
+package edu.uci.ics.hivesterix.logical.plan;
+
+import java.io.OutputStreamWriter;
+import java.io.PrintWriter;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Set;
+
+import org.apache.commons.lang3.mutable.Mutable;
+import org.apache.commons.lang3.mutable.MutableObject;
+import org.apache.hadoop.hive.ql.exec.ColumnInfo;
+import org.apache.hadoop.hive.ql.exec.ExtractOperator;
+import org.apache.hadoop.hive.ql.exec.FileSinkOperator;
+import org.apache.hadoop.hive.ql.exec.FilterOperator;
+import org.apache.hadoop.hive.ql.exec.GroupByOperator;
+import org.apache.hadoop.hive.ql.exec.JoinOperator;
+import org.apache.hadoop.hive.ql.exec.LateralViewJoinOperator;
+import org.apache.hadoop.hive.ql.exec.LimitOperator;
+import org.apache.hadoop.hive.ql.exec.MapJoinOperator;
+import org.apache.hadoop.hive.ql.exec.Operator;
+import org.apache.hadoop.hive.ql.exec.ReduceSinkOperator;
+import org.apache.hadoop.hive.ql.exec.SelectOperator;
+import org.apache.hadoop.hive.ql.exec.TableScanOperator;
+import org.apache.hadoop.hive.ql.exec.UDF;
+import org.apache.hadoop.hive.ql.exec.UDTFOperator;
+import org.apache.hadoop.hive.ql.exec.UnionOperator;
+import org.apache.hadoop.hive.ql.plan.AggregationDesc;
+import org.apache.hadoop.hive.ql.plan.ExprNodeColumnDesc;
+import org.apache.hadoop.hive.ql.plan.ExprNodeConstantDesc;
+import org.apache.hadoop.hive.ql.plan.ExprNodeDesc;
+import org.apache.hadoop.hive.ql.plan.ExprNodeFieldDesc;
+import org.apache.hadoop.hive.ql.plan.ExprNodeGenericFuncDesc;
+import org.apache.hadoop.hive.ql.plan.ExprNodeNullDesc;
+import org.apache.hadoop.hive.ql.plan.PartitionDesc;
+import org.apache.hadoop.hive.ql.plan.UDTFDesc;
+import org.apache.hadoop.hive.ql.plan.api.OperatorType;
+import org.apache.hadoop.hive.ql.udf.generic.GenericUDF;
+import org.apache.hadoop.hive.ql.udf.generic.GenericUDFBridge;
+import org.apache.hadoop.hive.serde2.typeinfo.TypeInfo;
+
+import edu.uci.ics.hivesterix.logical.expression.ExpressionConstant;
+import edu.uci.ics.hivesterix.logical.expression.HiveAlgebricksBuiltInFunctionMap;
+import edu.uci.ics.hivesterix.logical.expression.HiveFunctionInfo;
+import edu.uci.ics.hivesterix.logical.expression.HivesterixConstantValue;
+import edu.uci.ics.hivesterix.logical.plan.visitor.ExtractVisitor;
+import edu.uci.ics.hivesterix.logical.plan.visitor.FilterVisitor;
+import edu.uci.ics.hivesterix.logical.plan.visitor.GroupByVisitor;
+import edu.uci.ics.hivesterix.logical.plan.visitor.JoinVisitor;
+import edu.uci.ics.hivesterix.logical.plan.visitor.LateralViewJoinVisitor;
+import edu.uci.ics.hivesterix.logical.plan.visitor.LimitVisitor;
+import edu.uci.ics.hivesterix.logical.plan.visitor.MapJoinVisitor;
+import edu.uci.ics.hivesterix.logical.plan.visitor.ProjectVisitor;
+import edu.uci.ics.hivesterix.logical.plan.visitor.SortVisitor;
+import edu.uci.ics.hivesterix.logical.plan.visitor.TableScanWriteVisitor;
+import edu.uci.ics.hivesterix.logical.plan.visitor.UnionVisitor;
+import edu.uci.ics.hivesterix.logical.plan.visitor.base.Translator;
+import edu.uci.ics.hivesterix.logical.plan.visitor.base.Visitor;
+import edu.uci.ics.hivesterix.runtime.jobgen.Schema;
+import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalPlan;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalVariable;
+import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.AggregateFunctionCallExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.ConstantExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.ScalarFunctionCallExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.UnnestingFunctionCallExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.VariableReferenceExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
+import edu.uci.ics.hyracks.algebricks.core.algebra.metadata.IMetadataProvider;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.AssignOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.ReplicateOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.plan.ALogicalPlanImpl;
+import edu.uci.ics.hyracks.algebricks.core.algebra.prettyprint.LogicalOperatorPrettyPrintVisitor;
+import edu.uci.ics.hyracks.algebricks.core.algebra.prettyprint.PlanPrettyPrinter;
+
+@SuppressWarnings("rawtypes")
+public class HiveAlgebricksTranslator implements Translator {
+
+    private int currentVariable = 0;
+
+    private List<Mutable<ILogicalOperator>> logicalOp = new ArrayList<Mutable<ILogicalOperator>>();
+
+    private boolean continueTraverse = true;
+
+    private IMetadataProvider<PartitionDesc, Object> metaData;
+
+    /**
+     * map variable name to the logical variable
+     */
+    private HashMap<String, LogicalVariable> nameToLogicalVariableMap = new HashMap<String, LogicalVariable>();
+
+    /**
+     * map field name to LogicalVariable
+     */
+    private HashMap<String, LogicalVariable> fieldToLogicalVariableMap = new HashMap<String, LogicalVariable>();
+
+    /**
+     * map logical variable to name
+     */
+    private HashMap<LogicalVariable, String> logicalVariableToFieldMap = new HashMap<LogicalVariable, String>();
+
+    /**
+     * asterix root operators
+     */
+    private List<Mutable<ILogicalOperator>> rootOperators = new ArrayList<Mutable<ILogicalOperator>>();
+
+    /**
+     * a list of visitors
+     */
+    private List<Visitor> visitors = new ArrayList<Visitor>();
+
+    /**
+     * output writer to print things out
+     */
+    private static PrintWriter outputWriter = new PrintWriter(new OutputStreamWriter(System.out));
+
+    /**
+     * map a logical variable to type info
+     */
+    private HashMap<LogicalVariable, TypeInfo> variableToType = new HashMap<LogicalVariable, TypeInfo>();
+
+    @Override
+    public LogicalVariable getVariable(String fieldName, TypeInfo type) {
+        LogicalVariable var = fieldToLogicalVariableMap.get(fieldName);
+        if (var == null) {
+            currentVariable++;
+            var = new LogicalVariable(currentVariable);
+            fieldToLogicalVariableMap.put(fieldName, var);
+            nameToLogicalVariableMap.put(var.toString(), var);
+            variableToType.put(var, type);
+            logicalVariableToFieldMap.put(var, fieldName);
+        }
+        return var;
+    }
+
+    @Override
+    public LogicalVariable getNewVariable(String fieldName, TypeInfo type) {
+        currentVariable++;
+        LogicalVariable var = new LogicalVariable(currentVariable);
+        fieldToLogicalVariableMap.put(fieldName, var);
+        nameToLogicalVariableMap.put(var.toString(), var);
+        variableToType.put(var, type);
+        logicalVariableToFieldMap.put(var, fieldName);
+        return var;
+    }
+
+    @Override
+    public void replaceVariable(LogicalVariable oldVar, LogicalVariable newVar) {
+        String name = this.logicalVariableToFieldMap.get(oldVar);
+        if (name != null) {
+            fieldToLogicalVariableMap.put(name, newVar);
+            nameToLogicalVariableMap.put(newVar.toString(), newVar);
+            nameToLogicalVariableMap.put(oldVar.toString(), newVar);
+            logicalVariableToFieldMap.put(newVar, name);
+        }
+    }
+
+    @Override
+    public IMetadataProvider<PartitionDesc, Object> getMetadataProvider() {
+        return metaData;
+    }
+
+    /**
+     * only get an variable, without rewriting it
+     * 
+     * @param fieldName
+     * @return
+     */
+    private LogicalVariable getVariableOnly(String fieldName) {
+        return fieldToLogicalVariableMap.get(fieldName);
+    }
+
+    public void updateVariable(String fieldName, LogicalVariable variable) {
+        LogicalVariable var = fieldToLogicalVariableMap.get(fieldName);
+        if (var == null) {
+            fieldToLogicalVariableMap.put(fieldName, variable);
+            nameToLogicalVariableMap.put(fieldName, variable);
+        } else if (!var.equals(variable)) {
+            fieldToLogicalVariableMap.put(fieldName, variable);
+            nameToLogicalVariableMap.put(fieldName, variable);
+        }
+    }
+
+    /**
+     * get a list of logical variables from the schema
+     * 
+     * @param schema
+     * @return
+     */
+    @Override
+    public List<LogicalVariable> getVariablesFromSchema(Schema schema) {
+        List<LogicalVariable> variables = new ArrayList<LogicalVariable>();
+        List<String> names = schema.getNames();
+
+        for (String name : names)
+            variables.add(nameToLogicalVariableMap.get(name));
+        return variables;
+    }
+
+    /**
+     * get variable to typeinfo map
+     * 
+     * @return
+     */
+    public HashMap<LogicalVariable, TypeInfo> getVariableContext() {
+        return this.variableToType;
+    }
+
+    /**
+     * get the number of variables s
+     * 
+     * @return
+     */
+    public int getVariableCounter() {
+        return currentVariable + 1;
+    }
+
+    /**
+     * translate from hive operator tree to asterix operator tree
+     * 
+     * @param hive
+     *            roots
+     * @return Algebricks roots
+     */
+    public void translate(List<Operator> hiveRoot, ILogicalOperator parentOperator,
+            HashMap<String, PartitionDesc> aliasToPathMap) throws AlgebricksException {
+        /**
+         * register visitors
+         */
+        visitors.add(new FilterVisitor());
+        visitors.add(new GroupByVisitor());
+        visitors.add(new JoinVisitor());
+        visitors.add(new LateralViewJoinVisitor());
+        visitors.add(new UnionVisitor());
+        visitors.add(new LimitVisitor());
+        visitors.add(new MapJoinVisitor());
+        visitors.add(new ProjectVisitor());
+        visitors.add(new SortVisitor());
+        visitors.add(new ExtractVisitor());
+        visitors.add(new TableScanWriteVisitor(aliasToPathMap));
+
+        List<Mutable<ILogicalOperator>> refList = translate(hiveRoot, new MutableObject<ILogicalOperator>(
+                parentOperator));
+        insertReplicateOperator(refList);
+        if (refList != null)
+            rootOperators.addAll(refList);
+    }
+
+    /**
+     * translate operator DAG
+     * 
+     * @param hiveRoot
+     * @param AlgebricksParentOperator
+     * @return
+     */
+    private List<Mutable<ILogicalOperator>> translate(List<Operator> hiveRoot,
+            Mutable<ILogicalOperator> AlgebricksParentOperator) throws AlgebricksException {
+
+        for (Operator hiveOperator : hiveRoot) {
+            continueTraverse = true;
+            Mutable<ILogicalOperator> currentOperatorRef = null;
+            if (hiveOperator.getType() == OperatorType.FILTER) {
+                FilterOperator fop = (FilterOperator) hiveOperator;
+                for (Visitor visitor : visitors) {
+                    currentOperatorRef = visitor.visit(fop, AlgebricksParentOperator, this);
+                    if (currentOperatorRef != null)
+                        break;
+                }
+            } else if (hiveOperator.getType() == OperatorType.REDUCESINK) {
+                ReduceSinkOperator fop = (ReduceSinkOperator) hiveOperator;
+                for (Visitor visitor : visitors) {
+                    currentOperatorRef = visitor.visit(fop, AlgebricksParentOperator, this);
+                    if (currentOperatorRef != null)
+                        break;
+                }
+            } else if (hiveOperator.getType() == OperatorType.JOIN) {
+                JoinOperator fop = (JoinOperator) hiveOperator;
+                for (Visitor visitor : visitors) {
+                    currentOperatorRef = visitor.visit(fop, AlgebricksParentOperator, this);
+                    if (currentOperatorRef != null) {
+                        continueTraverse = true;
+                        break;
+                    } else
+                        continueTraverse = false;
+                }
+                if (currentOperatorRef == null)
+                    return null;
+            } else if (hiveOperator.getType() == OperatorType.LATERALVIEWJOIN) {
+                LateralViewJoinOperator fop = (LateralViewJoinOperator) hiveOperator;
+                for (Visitor visitor : visitors) {
+                    currentOperatorRef = visitor.visit(fop, AlgebricksParentOperator, this);
+                    if (currentOperatorRef != null)
+                        break;
+                }
+                if (currentOperatorRef == null)
+                    return null;
+            } else if (hiveOperator.getType() == OperatorType.MAPJOIN) {
+                MapJoinOperator fop = (MapJoinOperator) hiveOperator;
+                for (Visitor visitor : visitors) {
+                    currentOperatorRef = visitor.visit(fop, AlgebricksParentOperator, this);
+                    if (currentOperatorRef != null) {
+                        continueTraverse = true;
+                        break;
+                    } else
+                        continueTraverse = false;
+                }
+                if (currentOperatorRef == null)
+                    return null;
+            } else if (hiveOperator.getType() == OperatorType.SELECT) {
+                SelectOperator fop = (SelectOperator) hiveOperator;
+                for (Visitor visitor : visitors) {
+                    currentOperatorRef = visitor.visit(fop, AlgebricksParentOperator, this);
+                    if (currentOperatorRef != null)
+                        break;
+                }
+            } else if (hiveOperator.getType() == OperatorType.EXTRACT) {
+                ExtractOperator fop = (ExtractOperator) hiveOperator;
+                for (Visitor visitor : visitors) {
+                    currentOperatorRef = visitor.visit(fop, AlgebricksParentOperator, this);
+                    if (currentOperatorRef != null)
+                        break;
+                }
+            } else if (hiveOperator.getType() == OperatorType.GROUPBY) {
+                GroupByOperator fop = (GroupByOperator) hiveOperator;
+                for (Visitor visitor : visitors) {
+                    currentOperatorRef = visitor.visit(fop, AlgebricksParentOperator, this);
+                    if (currentOperatorRef != null)
+                        break;
+                }
+            } else if (hiveOperator.getType() == OperatorType.TABLESCAN) {
+                TableScanOperator fop = (TableScanOperator) hiveOperator;
+                for (Visitor visitor : visitors) {
+                    currentOperatorRef = visitor.visit(fop, AlgebricksParentOperator, this);
+                    if (currentOperatorRef != null)
+                        break;
+                }
+            } else if (hiveOperator.getType() == OperatorType.FILESINK) {
+                FileSinkOperator fop = (FileSinkOperator) hiveOperator;
+                for (Visitor visitor : visitors) {
+                    currentOperatorRef = visitor.visit(fop, AlgebricksParentOperator, this);
+                    if (currentOperatorRef != null)
+                        break;
+                }
+            } else if (hiveOperator.getType() == OperatorType.LIMIT) {
+                LimitOperator lop = (LimitOperator) hiveOperator;
+                for (Visitor visitor : visitors) {
+                    currentOperatorRef = visitor.visit(lop, AlgebricksParentOperator, this);
+                    if (currentOperatorRef != null)
+                        break;
+                }
+            } else if (hiveOperator.getType() == OperatorType.UDTF) {
+                UDTFOperator lop = (UDTFOperator) hiveOperator;
+                for (Visitor visitor : visitors) {
+                    currentOperatorRef = visitor.visit(lop, AlgebricksParentOperator, this);
+                    if (currentOperatorRef != null)
+                        break;
+                }
+            } else if (hiveOperator.getType() == OperatorType.UNION) {
+                UnionOperator lop = (UnionOperator) hiveOperator;
+                for (Visitor visitor : visitors) {
+                    currentOperatorRef = visitor.visit(lop, AlgebricksParentOperator, this);
+                    if (currentOperatorRef != null) {
+                        continueTraverse = true;
+                        break;
+                    } else
+                        continueTraverse = false;
+                }
+            } else
+                ;
+            if (hiveOperator.getChildOperators() != null && hiveOperator.getChildOperators().size() > 0
+                    && continueTraverse) {
+                @SuppressWarnings("unchecked")
+                List<Operator> children = hiveOperator.getChildOperators();
+                if (currentOperatorRef == null)
+                    currentOperatorRef = AlgebricksParentOperator;
+                translate(children, currentOperatorRef);
+            }
+            if (hiveOperator.getChildOperators() == null || hiveOperator.getChildOperators().size() == 0)
+                logicalOp.add(currentOperatorRef);
+        }
+        return logicalOp;
+    }
+
+    /**
+     * used in select, group by to get no-column-expression columns
+     * 
+     * @param cols
+     * @return
+     */
+    public ILogicalOperator getAssignOperator(Mutable<ILogicalOperator> parent, List<ExprNodeDesc> cols,
+            ArrayList<LogicalVariable> variables) {
+
+        ArrayList<Mutable<ILogicalExpression>> expressions = new ArrayList<Mutable<ILogicalExpression>>();
+
+        /**
+         * variables to be appended in the assign operator
+         */
+        ArrayList<LogicalVariable> appendedVariables = new ArrayList<LogicalVariable>();
+
+        // one variable can only be assigned once
+        for (ExprNodeDesc hiveExpr : cols) {
+            rewriteExpression(hiveExpr);
+
+            if (hiveExpr instanceof ExprNodeColumnDesc) {
+                ExprNodeColumnDesc desc2 = (ExprNodeColumnDesc) hiveExpr;
+                String fieldName = desc2.getTabAlias() + "." + desc2.getColumn();
+
+                // System.out.println("project expr: " + fieldName);
+
+                if (fieldName.indexOf("$$") < 0) {
+                    LogicalVariable var = getVariable(fieldName, hiveExpr.getTypeInfo());
+                    desc2.setColumn(var.toString());
+                    desc2.setTabAlias("");
+                    variables.add(var);
+                } else {
+                    LogicalVariable var = nameToLogicalVariableMap.get(desc2.getColumn());
+                    String name = this.logicalVariableToFieldMap.get(var);
+                    var = this.getVariableOnly(name);
+                    variables.add(var);
+                }
+            } else {
+                Mutable<ILogicalExpression> asterixExpr = translateScalarFucntion(hiveExpr);
+                expressions.add(asterixExpr);
+                LogicalVariable var = getVariable(hiveExpr.getExprString() + asterixExpr.hashCode(),
+                        hiveExpr.getTypeInfo());
+                variables.add(var);
+                appendedVariables.add(var);
+            }
+        }
+
+        /**
+         * create an assign operator to deal with appending
+         */
+        ILogicalOperator assignOp = null;
+        if (appendedVariables.size() > 0) {
+            assignOp = new AssignOperator(appendedVariables, expressions);
+            assignOp.getInputs().add(parent);
+        }
+        return assignOp;
+    }
+
+    private ILogicalPlan plan;
+
+    public ILogicalPlan genLogicalPlan() {
+        plan = new ALogicalPlanImpl(rootOperators);
+        return plan;
+    }
+
+    public void printOperators() throws AlgebricksException {
+        LogicalOperatorPrettyPrintVisitor pvisitor = new LogicalOperatorPrettyPrintVisitor();
+        StringBuilder buffer = new StringBuilder();
+        PlanPrettyPrinter.printPlan(plan, buffer, pvisitor, 0);
+        outputWriter.println(buffer);
+        outputWriter.println("rewritten variables: ");
+        outputWriter.flush();
+        printVariables();
+
+    }
+
+    public static void setOutputPrinter(PrintWriter writer) {
+        outputWriter = writer;
+    }
+
+    private void printVariables() {
+        Set<Entry<String, LogicalVariable>> entries = fieldToLogicalVariableMap.entrySet();
+
+        for (Entry<String, LogicalVariable> entry : entries) {
+            outputWriter.println(entry.getKey() + " -> " + entry.getValue());
+        }
+        outputWriter.flush();
+    }
+
+    /**
+     * generate the object inspector for the output of an operator
+     * 
+     * @param operator
+     *            The Hive operator
+     * @return an ObjectInspector object
+     */
+    public Schema generateInputSchema(Operator operator) {
+        List<String> variableNames = new ArrayList<String>();
+        List<TypeInfo> typeList = new ArrayList<TypeInfo>();
+        List<ColumnInfo> columns = operator.getSchema().getSignature();
+
+        for (ColumnInfo col : columns) {
+            // typeList.add();
+            TypeInfo type = col.getType();
+            typeList.add(type);
+
+            String fieldName = col.getInternalName();
+            variableNames.add(fieldName);
+        }
+
+        return new Schema(variableNames, typeList);
+    }
+
+    /**
+     * rewrite the names of output columns for feature expression evaluators to
+     * use
+     * 
+     * @param operator
+     */
+    public void rewriteOperatorOutputSchema(Operator operator) {
+        List<ColumnInfo> columns = operator.getSchema().getSignature();
+        for (ColumnInfo column : columns) {
+            String columnName = column.getTabAlias() + "." + column.getInternalName();
+            if (columnName.indexOf("$$") < 0) {
+                LogicalVariable var = getVariable(columnName, column.getType());
+                column.setInternalName(var.toString());
+            }
+        }
+    }
+
+    @Override
+    public void rewriteOperatorOutputSchema(List<LogicalVariable> variables, Operator operator) {
+        // printOperatorSchema(operator);
+        List<ColumnInfo> columns = operator.getSchema().getSignature();
+        // if (variables.size() != columns.size()) {
+        // throw new IllegalStateException("output cardinality error " +
+        // operator.getName() + " variable size: "
+        // + variables.size() + " expected " + columns.size());
+        // }
+        for (int i = 0; i < variables.size(); i++) {
+            LogicalVariable var = variables.get(i);
+            ColumnInfo column = columns.get(i);
+            String fieldName = column.getTabAlias() + "." + column.getInternalName();
+            if (fieldName.indexOf("$$") < 0) {
+                updateVariable(fieldName, var);
+                column.setInternalName(var.toString());
+            }
+        }
+
+        // printOperatorSchema(operator);
+    }
+
+    /**
+     * rewrite an expression and substitute variables
+     * 
+     * @param expr
+     *            hive expression
+     */
+    public void rewriteExpression(ExprNodeDesc expr) {
+        if (expr instanceof ExprNodeColumnDesc) {
+            ExprNodeColumnDesc desc = (ExprNodeColumnDesc) expr;
+            String fieldName = desc.getTabAlias() + "." + desc.getColumn();
+            if (fieldName.indexOf("$$") < 0) {
+                LogicalVariable var = getVariableOnly(fieldName);
+                if (var == null) {
+                    fieldName = "." + desc.getColumn();
+                    var = getVariableOnly(fieldName);
+                    if (var == null) {
+                        fieldName = "null." + desc.getColumn();
+                        var = getVariableOnly(fieldName);
+                        if (var == null) {
+                            throw new IllegalStateException(fieldName + " is wrong!!! ");
+                        }
+                    }
+                }
+                String name = this.logicalVariableToFieldMap.get(var);
+                var = getVariableOnly(name);
+                desc.setColumn(var.toString());
+            }
+        } else {
+            if (expr.getChildren() != null && expr.getChildren().size() > 0) {
+                List<ExprNodeDesc> children = expr.getChildren();
+                for (ExprNodeDesc desc : children)
+                    rewriteExpression(desc);
+            }
+        }
+    }
+
+    /**
+     * rewrite an expression and substitute variables
+     * 
+     * @param expr
+     *            hive expression
+     */
+    public void rewriteExpressionPartial(ExprNodeDesc expr) {
+        if (expr instanceof ExprNodeColumnDesc) {
+            ExprNodeColumnDesc desc = (ExprNodeColumnDesc) expr;
+            String fieldName = desc.getTabAlias() + "." + desc.getColumn();
+            if (fieldName.indexOf("$$") < 0) {
+                LogicalVariable var = getVariableOnly(fieldName);
+                desc.setColumn(var.toString());
+            }
+        } else {
+            if (expr.getChildren() != null && expr.getChildren().size() > 0) {
+                List<ExprNodeDesc> children = expr.getChildren();
+                for (ExprNodeDesc desc : children)
+                    rewriteExpressionPartial(desc);
+            }
+        }
+    }
+
+    // private void printOperatorSchema(Operator operator) {
+    // // System.out.println(operator.getName());
+    // // List<ColumnInfo> columns = operator.getSchema().getSignature();
+    // // for (ColumnInfo column : columns) {
+    // // System.out.print(column.getTabAlias() + "." +
+    // // column.getInternalName() + "  ");
+    // // }
+    // // System.out.println();
+    // }
+
+    /**
+     * translate scalar function expression
+     * 
+     * @param hiveExpr
+     * @return
+     */
+    public Mutable<ILogicalExpression> translateScalarFucntion(ExprNodeDesc hiveExpr) {
+        ILogicalExpression AlgebricksExpr;
+
+        if (hiveExpr instanceof ExprNodeGenericFuncDesc) {
+            List<Mutable<ILogicalExpression>> arguments = new ArrayList<Mutable<ILogicalExpression>>();
+            List<ExprNodeDesc> children = hiveExpr.getChildren();
+
+            for (ExprNodeDesc child : children)
+                arguments.add(translateScalarFucntion(child));
+
+            ExprNodeGenericFuncDesc funcExpr = (ExprNodeGenericFuncDesc) hiveExpr;
+            GenericUDF genericUdf = funcExpr.getGenericUDF();
+            UDF udf = null;
+            if (genericUdf instanceof GenericUDFBridge) {
+                GenericUDFBridge bridge = (GenericUDFBridge) genericUdf;
+                try {
+                    udf = bridge.getUdfClass().newInstance();
+                } catch (Exception e) {
+                    e.printStackTrace();
+                }
+            }
+
+            /**
+             * set up the hive function
+             */
+            Object hiveFunction = genericUdf;
+            if (udf != null)
+                hiveFunction = udf;
+
+            FunctionIdentifier funcId = HiveAlgebricksBuiltInFunctionMap.INSTANCE.getAlgebricksFunctionId(hiveFunction
+                    .getClass());
+            if (funcId == null) {
+                funcId = new FunctionIdentifier(ExpressionConstant.NAMESPACE, hiveFunction.getClass().getName());
+            }
+
+            Object functionInfo = null;
+            if (genericUdf instanceof GenericUDFBridge) {
+                functionInfo = funcExpr;
+            }
+
+            /**
+             * generate the function call expression
+             */
+            ScalarFunctionCallExpression AlgebricksFuncExpr = new ScalarFunctionCallExpression(new HiveFunctionInfo(
+                    funcId, functionInfo), arguments);
+            AlgebricksExpr = AlgebricksFuncExpr;
+
+        } else if (hiveExpr instanceof ExprNodeColumnDesc) {
+            ExprNodeColumnDesc column = (ExprNodeColumnDesc) hiveExpr;
+            LogicalVariable var = this.getVariable(column.getColumn());
+            AlgebricksExpr = new VariableReferenceExpression(var);
+
+        } else if (hiveExpr instanceof ExprNodeFieldDesc) {
+            FunctionIdentifier funcId;
+            funcId = new FunctionIdentifier(ExpressionConstant.NAMESPACE, ExpressionConstant.FIELDACCESS);
+
+            ScalarFunctionCallExpression AlgebricksFuncExpr = new ScalarFunctionCallExpression(new HiveFunctionInfo(
+                    funcId, hiveExpr));
+            AlgebricksExpr = AlgebricksFuncExpr;
+        } else if (hiveExpr instanceof ExprNodeConstantDesc) {
+            ExprNodeConstantDesc hiveConst = (ExprNodeConstantDesc) hiveExpr;
+            Object value = hiveConst.getValue();
+            AlgebricksExpr = new ConstantExpression(new HivesterixConstantValue(value));
+        } else if (hiveExpr instanceof ExprNodeNullDesc) {
+            FunctionIdentifier funcId;
+            funcId = new FunctionIdentifier(ExpressionConstant.NAMESPACE, ExpressionConstant.NULL);
+
+            ScalarFunctionCallExpression AlgebricksFuncExpr = new ScalarFunctionCallExpression(new HiveFunctionInfo(
+                    funcId, hiveExpr));
+
+            AlgebricksExpr = AlgebricksFuncExpr;
+        } else {
+            throw new IllegalStateException("unknown hive expression");
+        }
+        return new MutableObject<ILogicalExpression>(AlgebricksExpr);
+    }
+
+    /**
+     * translate aggregation function expression
+     * 
+     * @param aggregateDesc
+     * @return
+     */
+    public Mutable<ILogicalExpression> translateAggregation(AggregationDesc aggregateDesc) {
+
+        String UDAFName = aggregateDesc.getGenericUDAFName();
+
+        List<Mutable<ILogicalExpression>> arguments = new ArrayList<Mutable<ILogicalExpression>>();
+        List<ExprNodeDesc> children = aggregateDesc.getParameters();
+
+        for (ExprNodeDesc child : children)
+            arguments.add(translateScalarFucntion(child));
+
+        FunctionIdentifier funcId = new FunctionIdentifier(ExpressionConstant.NAMESPACE, UDAFName + "("
+                + aggregateDesc.getMode() + ")");
+        HiveFunctionInfo funcInfo = new HiveFunctionInfo(funcId, aggregateDesc);
+        AggregateFunctionCallExpression aggregationExpression = new AggregateFunctionCallExpression(funcInfo, false,
+                arguments);
+        return new MutableObject<ILogicalExpression>(aggregationExpression);
+    }
+
+    /**
+     * translate aggregation function expression
+     * 
+     * @param aggregator
+     * @return
+     */
+    public Mutable<ILogicalExpression> translateUnnestFunction(UDTFDesc udtfDesc, Mutable<ILogicalExpression> argument) {
+
+        String UDTFName = udtfDesc.getUDTFName();
+
+        FunctionIdentifier funcId = new FunctionIdentifier(ExpressionConstant.NAMESPACE, UDTFName);
+        UnnestingFunctionCallExpression unnestingExpression = new UnnestingFunctionCallExpression(new HiveFunctionInfo(
+                funcId, udtfDesc));
+        unnestingExpression.getArguments().add(argument);
+        return new MutableObject<ILogicalExpression>(unnestingExpression);
+    }
+
+    /**
+     * get typeinfo
+     */
+    @Override
+    public TypeInfo getType(LogicalVariable var) {
+        return variableToType.get(var);
+    }
+
+    /**
+     * get variable from variable name
+     */
+    @Override
+    public LogicalVariable getVariable(String name) {
+        return nameToLogicalVariableMap.get(name);
+    }
+
+    @Override
+    public LogicalVariable getVariableFromFieldName(String fieldName) {
+        return this.getVariableOnly(fieldName);
+    }
+
+    /**
+     * set the metadata provider
+     */
+    @Override
+    public void setMetadataProvider(IMetadataProvider<PartitionDesc, Object> metadata) {
+        this.metaData = metadata;
+    }
+
+    /**
+     * insert ReplicateOperator when necessary
+     */
+    private void insertReplicateOperator(List<Mutable<ILogicalOperator>> roots) {
+        Map<Mutable<ILogicalOperator>, List<Mutable<ILogicalOperator>>> childToParentsMap = new HashMap<Mutable<ILogicalOperator>, List<Mutable<ILogicalOperator>>>();
+        buildChildToParentsMapping(roots, childToParentsMap);
+        for (Entry<Mutable<ILogicalOperator>, List<Mutable<ILogicalOperator>>> entry : childToParentsMap.entrySet()) {
+            List<Mutable<ILogicalOperator>> pList = entry.getValue();
+            if (pList.size() > 1) {
+                ILogicalOperator rop = new ReplicateOperator(pList.size());
+                Mutable<ILogicalOperator> ropRef = new MutableObject<ILogicalOperator>(rop);
+                Mutable<ILogicalOperator> childRef = entry.getKey();
+                rop.getInputs().add(childRef);
+                for (Mutable<ILogicalOperator> parentRef : pList) {
+                    ILogicalOperator parentOp = parentRef.getValue();
+                    int index = parentOp.getInputs().indexOf(childRef);
+                    parentOp.getInputs().set(index, ropRef);
+                }
+            }
+        }
+    }
+
+    /**
+     * build the mapping from child to Parents
+     * 
+     * @param roots
+     * @param childToParentsMap
+     */
+    private void buildChildToParentsMapping(List<Mutable<ILogicalOperator>> roots,
+            Map<Mutable<ILogicalOperator>, List<Mutable<ILogicalOperator>>> map) {
+        for (Mutable<ILogicalOperator> opRef : roots) {
+            List<Mutable<ILogicalOperator>> childRefs = opRef.getValue().getInputs();
+            for (Mutable<ILogicalOperator> childRef : childRefs) {
+                List<Mutable<ILogicalOperator>> parentList = map.get(childRef);
+                if (parentList == null) {
+                    parentList = new ArrayList<Mutable<ILogicalOperator>>();
+                    map.put(childRef, parentList);
+                }
+                if (!parentList.contains(opRef))
+                    parentList.add(opRef);
+            }
+            buildChildToParentsMapping(childRefs, map);
+        }
+    }
+}
diff --git a/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/visitor/LateralViewJoinVisitor.java b/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/visitor/LateralViewJoinVisitor.java
index f4161a4..aa1837c 100644
--- a/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/visitor/LateralViewJoinVisitor.java
+++ b/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/visitor/LateralViewJoinVisitor.java
@@ -12,113 +12,145 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package edu.uci.ics.hivesterix.logical.plan.visitor;
-
-import java.util.ArrayList;
-import java.util.List;
-
-import org.apache.commons.lang3.mutable.Mutable;
-import org.apache.commons.lang3.mutable.MutableObject;
-import org.apache.hadoop.hive.ql.exec.LateralViewJoinOperator;
-import org.apache.hadoop.hive.ql.exec.Operator;
-import org.apache.hadoop.hive.ql.exec.UDTFOperator;
-import org.apache.hadoop.hive.ql.plan.UDTFDesc;
-import org.apache.hadoop.hive.serde2.typeinfo.TypeInfoFactory;
-
-import edu.uci.ics.hivesterix.logical.plan.visitor.base.DefaultVisitor;
-import edu.uci.ics.hivesterix.logical.plan.visitor.base.Translator;
-import edu.uci.ics.hivesterix.runtime.jobgen.Schema;
-import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
-import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalExpression;
-import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalOperator;
-import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalVariable;
-import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.VariableReferenceExpression;
-import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.UnnestOperator;
-import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.visitors.VariableUtilities;
-
-/**
- * The lateral view join operator is used for FROM src LATERAL VIEW udtf()...
- * This operator was implemented with the following operator DAG in mind.
- * For a query such as
- * SELECT pageid, adid.* FROM example_table LATERAL VIEW explode(adid_list) AS
- * adid
- * The top of the operator DAG will look similar to
- * [Table Scan] | [Lateral View Forward] / \ [Select](*) [Select](adid_list) | |
- * | [UDTF] (explode) \ / [Lateral View Join] | | [Select] (pageid, adid.*) |
- * ....
- * Rows from the table scan operator are first to a lateral view forward
- * operator that just forwards the row and marks the start of a LV. The select
- * operator on the left picks all the columns while the select operator on the
- * right picks only the columns needed by the UDTF.
- * The output of select in the left branch and output of the UDTF in the right
- * branch are then sent to the lateral view join (LVJ). In most cases, the UDTF
- * will generate > 1 row for every row received from the TS, while the left
- * select operator will generate only one. For each row output from the TS, the
- * LVJ outputs all possible rows that can be created by joining the row from the
- * left select and one of the rows output from the UDTF.
- * Additional lateral views can be supported by adding a similar DAG after the
- * previous LVJ operator.
- */
-
-@SuppressWarnings("rawtypes")
-public class LateralViewJoinVisitor extends DefaultVisitor {
-
-    private UDTFDesc udtf;
-
-    private List<Mutable<ILogicalOperator>> parents = new ArrayList<Mutable<ILogicalOperator>>();
-
-    @Override
-    public Mutable<ILogicalOperator> visit(LateralViewJoinOperator operator,
-            Mutable<ILogicalOperator> AlgebricksParentOperatorRef, Translator t) throws AlgebricksException {
-
-        parents.add(AlgebricksParentOperatorRef);
-        if (operator.getParentOperators().size() > parents.size()) {
-            return null;
-        }
-
-        Operator parent0 = operator.getParentOperators().get(0);
-        ILogicalOperator parentOperator;
-        ILogicalExpression unnestArg;
-        if (parent0 instanceof UDTFOperator) {
-            List<LogicalVariable> unnestVars = new ArrayList<LogicalVariable>();
-            VariableUtilities.getLiveVariables(parents.get(1).getValue(), unnestVars);
-            unnestArg = new VariableReferenceExpression(unnestVars.get(0));
-            parentOperator = parents.get(1).getValue();
-        } else {
-            List<LogicalVariable> unnestVars = new ArrayList<LogicalVariable>();
-            VariableUtilities.getLiveVariables(parents.get(0).getValue(), unnestVars);
-            unnestArg = new VariableReferenceExpression(unnestVars.get(0));
-            parentOperator = parents.get(0).getValue();
-        }
-
-        LogicalVariable var = t.getVariable(udtf.toString(), TypeInfoFactory.unknownTypeInfo);
-
-        Mutable<ILogicalExpression> unnestExpr = t.translateUnnestFunction(udtf, new MutableObject<ILogicalExpression>(
-                unnestArg));
-        ILogicalOperator currentOperator = new UnnestOperator(var, unnestExpr);
-
-        List<LogicalVariable> outputVars = new ArrayList<LogicalVariable>();
-        VariableUtilities.getLiveVariables(parentOperator, outputVars);
-        outputVars.add(var);
-        currentOperator.getInputs().add(new MutableObject<ILogicalOperator>(parentOperator));
-
-        parents.clear();
-        udtf = null;
-        t.rewriteOperatorOutputSchema(outputVars, operator);
-        return new MutableObject<ILogicalOperator>(currentOperator);
-    }
-
-    @Override
-    public Mutable<ILogicalOperator> visit(UDTFOperator operator,
-            Mutable<ILogicalOperator> AlgebricksParentOperatorRef, Translator t) {
-        Schema currentSchema = t.generateInputSchema(operator.getParentOperators().get(0));
-        udtf = (UDTFDesc) operator.getConf();
-
-        // populate the schema from upstream operator
-        operator.setSchema(operator.getParentOperators().get(0).getSchema());
-        List<LogicalVariable> latestOutputSchema = t.getVariablesFromSchema(currentSchema);
-        t.rewriteOperatorOutputSchema(latestOutputSchema, operator);
-        return null;
-    }
-
-}
+package edu.uci.ics.hivesterix.logical.plan.visitor;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.commons.lang3.mutable.Mutable;
+import org.apache.commons.lang3.mutable.MutableObject;
+import org.apache.hadoop.hive.ql.exec.ColumnInfo;
+import org.apache.hadoop.hive.ql.exec.LateralViewJoinOperator;
+import org.apache.hadoop.hive.ql.exec.Operator;
+import org.apache.hadoop.hive.ql.exec.UDTFOperator;
+import org.apache.hadoop.hive.ql.plan.LateralViewJoinDesc;
+import org.apache.hadoop.hive.ql.plan.UDTFDesc;
+import org.apache.hadoop.hive.serde2.typeinfo.TypeInfoFactory;
+
+import edu.uci.ics.hivesterix.logical.plan.visitor.base.DefaultVisitor;
+import edu.uci.ics.hivesterix.logical.plan.visitor.base.Translator;
+import edu.uci.ics.hivesterix.runtime.jobgen.Schema;
+import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalVariable;
+import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.VariableReferenceExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.ProjectOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.UnnestOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.visitors.VariableUtilities;
+
+/**
+ * The lateral view join operator is used for FROM src LATERAL VIEW udtf()...
+ * This operator was implemented with the following operator DAG in mind.
+ * For a query such as
+ * SELECT pageid, adid.* FROM example_table LATERAL VIEW explode(adid_list) AS
+ * adid
+ * The top of the operator DAG will look similar to
+ * [Table Scan] | [Lateral View Forward] / \ [Select](*) [Select](adid_list) | |
+ * | [UDTF] (explode) \ / [Lateral View Join] | | [Select] (pageid, adid.*) |
+ * ....
+ * Rows from the table scan operator are first to a lateral view forward
+ * operator that just forwards the row and marks the start of a LV. The select
+ * operator on the left picks all the columns while the select operator on the
+ * right picks only the columns needed by the UDTF.
+ * The output of select in the left branch and output of the UDTF in the right
+ * branch are then sent to the lateral view join (LVJ). In most cases, the UDTF
+ * will generate > 1 row for every row received from the TS, while the left
+ * select operator will generate only one. For each row output from the TS, the
+ * LVJ outputs all possible rows that can be created by joining the row from the
+ * left select and one of the rows output from the UDTF.
+ * Additional lateral views can be supported by adding a similar DAG after the
+ * previous LVJ operator.
+ */
+
+@SuppressWarnings("rawtypes")
+public class LateralViewJoinVisitor extends DefaultVisitor {
+
+    private UDTFDesc udtf;
+
+    private List<Mutable<ILogicalOperator>> parents = new ArrayList<Mutable<ILogicalOperator>>();
+
+    @Override
+    public Mutable<ILogicalOperator> visit(LateralViewJoinOperator operator,
+            Mutable<ILogicalOperator> AlgebricksParentOperatorRef, Translator t) throws AlgebricksException {
+
+        parents.add(AlgebricksParentOperatorRef);
+        if (operator.getParentOperators().size() > parents.size()) {
+            return null;
+        }
+
+        ILogicalOperator parentOperator = null;
+        ILogicalExpression unnestArg = null;
+        List<LogicalVariable> projectVariables = new ArrayList<LogicalVariable>();
+        for (Mutable<ILogicalOperator> parentLOpRef : parents) {
+            VariableUtilities.getLiveVariables(parentLOpRef.getValue(), projectVariables);
+        }
+        for (Operator parentOp : operator.getParentOperators()) {
+            if (parentOp instanceof UDTFOperator) {
+                int index = operator.getParentOperators().indexOf(parentOp);
+                List<LogicalVariable> unnestVars = new ArrayList<LogicalVariable>();
+                VariableUtilities.getLiveVariables(parents.get(index).getValue(), unnestVars);
+                unnestArg = new VariableReferenceExpression(unnestVars.get(0));
+                parentOperator = parents.get(index).getValue();
+            }
+        }
+
+        LogicalVariable var = t.getVariable(udtf.toString(), TypeInfoFactory.unknownTypeInfo);
+        Mutable<ILogicalExpression> unnestExpr = t.translateUnnestFunction(udtf, new MutableObject<ILogicalExpression>(
+                unnestArg));
+        ILogicalOperator currentOperator = new UnnestOperator(var, unnestExpr);
+
+        List<LogicalVariable> outputVars = new ArrayList<LogicalVariable>();
+        VariableUtilities.getLiveVariables(parents.get(0).getValue(), outputVars);
+        outputVars.add(var);
+        ILogicalOperator inputProjectOperator = new ProjectOperator(projectVariables);
+        currentOperator.getInputs().add(new MutableObject<ILogicalOperator>(inputProjectOperator));
+        inputProjectOperator.getInputs().addAll(parentOperator.getInputs());
+
+        parents.clear();
+        udtf = null;
+        List<ColumnInfo> inputSchema = operator.getSchema().getSignature();
+        rewriteOperatorDesc(outputVars, operator.getConf(), inputSchema, t);
+        //t.rewriteOperatorOutputSchema(outputVars, operator);
+        return new MutableObject<ILogicalOperator>(currentOperator);
+    }
+
+    @Override
+    public Mutable<ILogicalOperator> visit(UDTFOperator operator,
+            Mutable<ILogicalOperator> AlgebricksParentOperatorRef, Translator t) {
+        Schema currentSchema = t.generateInputSchema(operator.getParentOperators().get(0));
+        udtf = (UDTFDesc) operator.getConf();
+
+        // populate the schema from upstream operator
+        operator.setSchema(operator.getParentOperators().get(0).getSchema());
+        List<LogicalVariable> latestOutputSchema = t.getVariablesFromSchema(currentSchema);
+        t.rewriteOperatorOutputSchema(latestOutputSchema, operator);
+        return null;
+    }
+
+    private void rewriteOperatorDesc(List<LogicalVariable> variables, LateralViewJoinDesc desc,
+            List<ColumnInfo> schema, Translator t) {
+        List<String> outputFieldNames = desc.getOutputInternalColNames();
+        for (int i = 0; i < variables.size(); i++) {
+            LogicalVariable var = variables.get(i);
+            String fieldName = outputFieldNames.get(i);
+            String tabAlias = findTabAlias(fieldName, schema);
+            fieldName = tabAlias + "." + fieldName;
+            if (fieldName.indexOf("$$") < 0) {
+                //outputFieldNames.set(i, var.toString());
+                t.updateVariable(fieldName, var);
+            }
+        }
+    }
+
+    private String findTabAlias(String fieldName, List<ColumnInfo> schema) {
+        for (int i = 0; i < schema.size(); i++) {
+            ColumnInfo column = schema.get(i);
+            if (column.getInternalName().equals(fieldName)) {
+                return column.getTabAlias();
+            }
+        }
+        return "null";
+    }
+
+}
diff --git a/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/visitor/MapJoinVisitor.java b/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/visitor/MapJoinVisitor.java
index 186b291..3ed9786 100644
--- a/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/visitor/MapJoinVisitor.java
+++ b/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/visitor/MapJoinVisitor.java
@@ -14,36 +14,36 @@
  */
 package edu.uci.ics.hivesterix.logical.plan.visitor;
 
-import java.io.Serializable;
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Map;
-import java.util.Map.Entry;
-import java.util.Set;
-
-import org.apache.commons.lang3.mutable.Mutable;
-import org.apache.commons.lang3.mutable.MutableObject;
-import org.apache.hadoop.hive.ql.exec.ColumnInfo;
-import org.apache.hadoop.hive.ql.exec.MapJoinOperator;
-import org.apache.hadoop.hive.ql.exec.Operator;
-import org.apache.hadoop.hive.ql.plan.ExprNodeConstantDesc;
-import org.apache.hadoop.hive.ql.plan.ExprNodeDesc;
-import org.apache.hadoop.hive.ql.plan.ExprNodeGenericFuncDesc;
-import org.apache.hadoop.hive.ql.plan.MapJoinDesc;
-import org.apache.hadoop.hive.ql.udf.generic.GenericUDFOPAnd;
-import org.apache.hadoop.hive.ql.udf.generic.GenericUDFOPEqual;
-import org.apache.hadoop.hive.serde2.typeinfo.TypeInfo;
-import org.apache.hadoop.hive.serde2.typeinfo.TypeInfoFactory;
-
-import edu.uci.ics.hivesterix.logical.plan.visitor.base.DefaultVisitor;
-import edu.uci.ics.hivesterix.logical.plan.visitor.base.Translator;
-import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalExpression;
-import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalOperator;
-import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalVariable;
-import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.InnerJoinOperator;
-import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.ProjectOperator;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Set;
+
+import org.apache.commons.lang3.mutable.Mutable;
+import org.apache.commons.lang3.mutable.MutableObject;
+import org.apache.hadoop.hive.ql.exec.ColumnInfo;
+import org.apache.hadoop.hive.ql.exec.MapJoinOperator;
+import org.apache.hadoop.hive.ql.exec.Operator;
+import org.apache.hadoop.hive.ql.plan.ExprNodeConstantDesc;
+import org.apache.hadoop.hive.ql.plan.ExprNodeDesc;
+import org.apache.hadoop.hive.ql.plan.ExprNodeGenericFuncDesc;
+import org.apache.hadoop.hive.ql.plan.MapJoinDesc;
+import org.apache.hadoop.hive.ql.plan.OperatorDesc;
+import org.apache.hadoop.hive.ql.udf.generic.GenericUDFOPAnd;
+import org.apache.hadoop.hive.ql.udf.generic.GenericUDFOPEqual;
+import org.apache.hadoop.hive.serde2.typeinfo.TypeInfo;
+import org.apache.hadoop.hive.serde2.typeinfo.TypeInfoFactory;
+
+import edu.uci.ics.hivesterix.logical.plan.visitor.base.DefaultVisitor;
+import edu.uci.ics.hivesterix.logical.plan.visitor.base.Translator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalVariable;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.InnerJoinOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.ProjectOperator;
 
 @SuppressWarnings("rawtypes")
 public class MapJoinVisitor extends DefaultVisitor {
@@ -56,7 +56,7 @@
     @Override
     public Mutable<ILogicalOperator> visit(MapJoinOperator operator,
             Mutable<ILogicalOperator> AlgebricksParentOperatorRef, Translator t) {
-        List<Operator<? extends Serializable>> joinSrc = operator.getParentOperators();
+        List<Operator<? extends OperatorDesc>> joinSrc = operator.getParentOperators();
         List<Mutable<ILogicalOperator>> parents = opMap.get(operator);
         if (parents == null) {
             parents = new ArrayList<Mutable<ILogicalOperator>>();
diff --git a/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/visitor/TableScanWriteVisitor.java b/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/visitor/TableScanWriteVisitor.java
index 74cebaa..25abdec 100644
--- a/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/visitor/TableScanWriteVisitor.java
+++ b/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/visitor/TableScanWriteVisitor.java
@@ -69,9 +69,9 @@
 
     @Override
     public Mutable<ILogicalOperator> visit(TableScanOperator operator,
-            Mutable<ILogicalOperator> AlgebricksParentOperator, Translator t) throws AlgebricksException {
+            Mutable<ILogicalOperator> AlgebricksParentOperator, Translator t) throws AlgebricksException {    	
         TableScanDesc desc = (TableScanDesc) operator.getConf();
-        if (desc == null) {
+        if (desc == null || desc.getAlias()==null) {
             List<LogicalVariable> schema = new ArrayList<LogicalVariable>();
             VariableUtilities.getLiveVariables(AlgebricksParentOperator.getValue(), schema);
             t.rewriteOperatorOutputSchema(schema, operator);
@@ -124,7 +124,6 @@
     @Override
     public Mutable<ILogicalOperator> visit(FileSinkOperator hiveOperator,
             Mutable<ILogicalOperator> AlgebricksParentOperator, Translator t) {
-
         if (hiveOperator.getChildOperators() != null && hiveOperator.getChildOperators().size() > 0)
             return null;
 
diff --git a/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/visitor/UnionVisitor.java b/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/visitor/UnionVisitor.java
index 1cb5121..c710f3f 100644
--- a/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/visitor/UnionVisitor.java
+++ b/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/visitor/UnionVisitor.java
@@ -14,21 +14,21 @@
  */
 package edu.uci.ics.hivesterix.logical.plan.visitor;
 
-import java.util.ArrayList;
-import java.util.List;
-
-import org.apache.commons.lang3.mutable.Mutable;
-import org.apache.commons.lang3.mutable.MutableObject;
-import org.apache.hadoop.hive.ql.exec.UnionOperator;
-import org.apache.hadoop.hive.serde2.typeinfo.TypeInfoFactory;
-
-import edu.uci.ics.hivesterix.logical.plan.visitor.base.DefaultVisitor;
-import edu.uci.ics.hivesterix.logical.plan.visitor.base.Translator;
-import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
-import edu.uci.ics.hyracks.algebricks.common.utils.Triple;
-import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalOperator;
-import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalVariable;
-import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.visitors.VariableUtilities;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.commons.lang3.mutable.Mutable;
+import org.apache.commons.lang3.mutable.MutableObject;
+import org.apache.hadoop.hive.ql.exec.UnionOperator;
+import org.apache.hadoop.hive.serde2.typeinfo.TypeInfoFactory;
+
+import edu.uci.ics.hivesterix.logical.plan.visitor.base.DefaultVisitor;
+import edu.uci.ics.hivesterix.logical.plan.visitor.base.Translator;
+import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
+import edu.uci.ics.hyracks.algebricks.common.utils.Triple;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalVariable;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.visitors.VariableUtilities;
 
 public class UnionVisitor extends DefaultVisitor {
 
@@ -46,8 +46,8 @@
         List<LogicalVariable> leftVars = new ArrayList<LogicalVariable>();
         List<LogicalVariable> rightVars = new ArrayList<LogicalVariable>();
 
-        VariableUtilities.getUsedVariables(parents.get(0).getValue(), leftVars);
-        VariableUtilities.getUsedVariables(parents.get(1).getValue(), rightVars);
+        VariableUtilities.getLiveVariables(parents.get(0).getValue(), leftVars);
+        VariableUtilities.getLiveVariables(parents.get(1).getValue(), rightVars);
 
         List<Triple<LogicalVariable, LogicalVariable, LogicalVariable>> triples = new ArrayList<Triple<LogicalVariable, LogicalVariable, LogicalVariable>>();
         List<LogicalVariable> unionVars = new ArrayList<LogicalVariable>();
diff --git a/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/visitor/base/Translator.java b/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/visitor/base/Translator.java
index 32b0f66..5b6ac50 100644
--- a/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/visitor/base/Translator.java
+++ b/hivesterix/hivesterix-translator/src/main/java/edu/uci/ics/hivesterix/logical/plan/visitor/base/Translator.java
@@ -12,173 +12,181 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package edu.uci.ics.hivesterix.logical.plan.visitor.base;
-
-import java.util.ArrayList;
-import java.util.List;
-
-import org.apache.commons.lang3.mutable.Mutable;
-import org.apache.hadoop.hive.ql.exec.Operator;
-import org.apache.hadoop.hive.ql.plan.AggregationDesc;
-import org.apache.hadoop.hive.ql.plan.ExprNodeDesc;
-import org.apache.hadoop.hive.ql.plan.PartitionDesc;
-import org.apache.hadoop.hive.ql.plan.UDTFDesc;
-import org.apache.hadoop.hive.serde2.typeinfo.TypeInfo;
-
-import edu.uci.ics.hivesterix.runtime.jobgen.Schema;
-import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalExpression;
-import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalOperator;
-import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalVariable;
-import edu.uci.ics.hyracks.algebricks.core.algebra.metadata.IMetadataProvider;
-
-@SuppressWarnings("rawtypes")
-public interface Translator {
-
-    /**
-     * generate input schema
-     * 
-     * @param operator
-     * @return
-     */
-    public Schema generateInputSchema(Operator operator);
-
-    /**
-     * rewrite the names of output columns for feture expression evaluators to
-     * use
-     * 
-     * @param operator
-     */
-    public void rewriteOperatorOutputSchema(List<LogicalVariable> vars, Operator operator);
-
-    /**
-     * rewrite the names of output columns for feture expression evaluators to
-     * use
-     * 
-     * @param operator
-     */
-    public void rewriteOperatorOutputSchema(Operator operator);
-
-    /**
-     * rewrite an expression and substitute variables
-     * 
-     * @param expr
-     *            hive expression
-     */
-    public void rewriteExpression(ExprNodeDesc expr);
-
-    /**
-     * rewrite an expression and substitute variables
-     * 
-     * @param expr
-     *            hive expression
-     */
-    public void rewriteExpressionPartial(ExprNodeDesc expr);
-
-    /**
-     * get an assign operator as a child of parent
-     * 
-     * @param parent
-     * @param cols
-     * @param variables
-     * @return
-     */
-    public ILogicalOperator getAssignOperator(Mutable<ILogicalOperator> parent, List<ExprNodeDesc> cols,
-            ArrayList<LogicalVariable> variables);
-
-    /**
-     * get type for a logical variable
-     * 
-     * @param var
-     * @return type info
-     */
-    public TypeInfo getType(LogicalVariable var);
-
-    /**
-     * translate an expression from hive to Algebricks
-     * 
-     * @param desc
-     * @return
-     */
-    public Mutable<ILogicalExpression> translateScalarFucntion(ExprNodeDesc desc);
-
-    /**
-     * translate an aggregation from hive to Algebricks
-     * 
-     * @param aggregateDesc
-     * @return
-     */
-    public Mutable<ILogicalExpression> translateAggregation(AggregationDesc aggregateDesc);
-
-    /**
-     * translate unnesting (UDTF) function expression
-     * 
-     * @param aggregator
-     * @return
-     */
-    public Mutable<ILogicalExpression> translateUnnestFunction(UDTFDesc udtfDesc, Mutable<ILogicalExpression> argument);
-
-    /**
-     * get variable from a schema
-     * 
-     * @param schema
-     * @return
-     */
-    public List<LogicalVariable> getVariablesFromSchema(Schema schema);
-
-    /**
-     * get variable from name
-     * 
-     * @param name
-     * @return
-     */
-    public LogicalVariable getVariable(String name);
-
-    /**
-     * get variable from field name
-     * 
-     * @param name
-     * @return
-     */
-    public LogicalVariable getVariableFromFieldName(String name);
-
-    /**
-     * get variable from name, type
-     * 
-     * @param fieldName
-     * @param type
-     * @return
-     */
-    public LogicalVariable getVariable(String fieldName, TypeInfo type);
-
-    /**
-     * get new variable from name, type
-     * 
-     * @param fieldName
-     * @param type
-     * @return
-     */
-    public LogicalVariable getNewVariable(String fieldName, TypeInfo type);
-
-    /**
-     * set the metadata provider
-     * 
-     * @param metadata
-     */
-    public void setMetadataProvider(IMetadataProvider<PartitionDesc, Object> metadata);
-
-    /**
-     * get the metadata provider
-     * 
-     * @param metadata
-     */
-    public IMetadataProvider<PartitionDesc, Object> getMetadataProvider();
-
-    /**
-     * replace the variable
-     * 
-     * @param oldVar
-     * @param newVar
-     */
-    public void replaceVariable(LogicalVariable oldVar, LogicalVariable newVar);
-
-}
+package edu.uci.ics.hivesterix.logical.plan.visitor.base;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.commons.lang3.mutable.Mutable;
+import org.apache.hadoop.hive.ql.exec.Operator;
+import org.apache.hadoop.hive.ql.plan.AggregationDesc;
+import org.apache.hadoop.hive.ql.plan.ExprNodeDesc;
+import org.apache.hadoop.hive.ql.plan.PartitionDesc;
+import org.apache.hadoop.hive.ql.plan.UDTFDesc;
+import org.apache.hadoop.hive.serde2.typeinfo.TypeInfo;
+
+import edu.uci.ics.hivesterix.runtime.jobgen.Schema;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalVariable;
+import edu.uci.ics.hyracks.algebricks.core.algebra.metadata.IMetadataProvider;
+
+@SuppressWarnings("rawtypes")
+public interface Translator {
+
+    /**
+     * generate input schema
+     * 
+     * @param operator
+     * @return
+     */
+    public Schema generateInputSchema(Operator operator);
+
+    /**
+     * rewrite the names of output columns for feture expression evaluators to
+     * use
+     * 
+     * @param operator
+     */
+    public void rewriteOperatorOutputSchema(List<LogicalVariable> vars, Operator operator);
+
+    /**
+     * rewrite the names of output columns for feture expression evaluators to
+     * use
+     * 
+     * @param operator
+     */
+    public void rewriteOperatorOutputSchema(Operator operator);
+
+    /**
+     * rewrite an expression and substitute variables
+     * 
+     * @param expr
+     *            hive expression
+     */
+    public void rewriteExpression(ExprNodeDesc expr);
+
+    /**
+     * rewrite an expression and substitute variables
+     * 
+     * @param expr
+     *            hive expression
+     */
+    public void rewriteExpressionPartial(ExprNodeDesc expr);
+
+    /**
+     * get an assign operator as a child of parent
+     * 
+     * @param parent
+     * @param cols
+     * @param variables
+     * @return
+     */
+    public ILogicalOperator getAssignOperator(Mutable<ILogicalOperator> parent, List<ExprNodeDesc> cols,
+            ArrayList<LogicalVariable> variables);
+
+    /**
+     * get type for a logical variable
+     * 
+     * @param var
+     * @return type info
+     */
+    public TypeInfo getType(LogicalVariable var);
+
+    /**
+     * translate an expression from hive to Algebricks
+     * 
+     * @param desc
+     * @return
+     */
+    public Mutable<ILogicalExpression> translateScalarFucntion(ExprNodeDesc desc);
+
+    /**
+     * translate an aggregation from hive to Algebricks
+     * 
+     * @param aggregateDesc
+     * @return
+     */
+    public Mutable<ILogicalExpression> translateAggregation(AggregationDesc aggregateDesc);
+
+    /**
+     * translate unnesting (UDTF) function expression
+     * 
+     * @param aggregator
+     * @return
+     */
+    public Mutable<ILogicalExpression> translateUnnestFunction(UDTFDesc udtfDesc, Mutable<ILogicalExpression> argument);
+
+    /**
+     * get variable from a schema
+     * 
+     * @param schema
+     * @return
+     */
+    public List<LogicalVariable> getVariablesFromSchema(Schema schema);
+
+    /**
+     * get variable from name
+     * 
+     * @param name
+     * @return
+     */
+    public LogicalVariable getVariable(String name);
+
+    /**
+     * get variable from field name
+     * 
+     * @param name
+     * @return
+     */
+    public LogicalVariable getVariableFromFieldName(String name);
+
+    /**
+     * get variable from name, type
+     * 
+     * @param fieldName
+     * @param type
+     * @return
+     */
+    public LogicalVariable getVariable(String fieldName, TypeInfo type);
+
+    /**
+     * get new variable from name, type
+     * 
+     * @param fieldName
+     * @param type
+     * @return
+     */
+    public LogicalVariable getNewVariable(String fieldName, TypeInfo type);
+
+    /**
+     * update a name-variable binding
+     * 
+     * @param fieldName
+     * @param variable
+     */
+    public void updateVariable(String fieldName, LogicalVariable variable);
+
+    /**
+     * set the metadata provider
+     * 
+     * @param metadata
+     */
+    public void setMetadataProvider(IMetadataProvider<PartitionDesc, Object> metadata);
+
+    /**
+     * get the metadata provider
+     * 
+     * @param metadata
+     */
+    public IMetadataProvider<PartitionDesc, Object> getMetadataProvider();
+
+    /**
+     * replace the variable
+     * 
+     * @param oldVar
+     * @param newVar
+     */
+    public void replaceVariable(LogicalVariable oldVar, LogicalVariable newVar);
+
+}
diff --git a/hivesterix/pom.xml b/hivesterix/pom.xml
index 2bee50c..ba43c0d 100644
--- a/hivesterix/pom.xml
+++ b/hivesterix/pom.xml
@@ -17,7 +17,7 @@
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>edu.uci.ics.hyracks</groupId>
 	<artifactId>hivesterix</artifactId>
-	<version>0.2.7-SNAPSHOT</version>
+	<version>0.2.10-SNAPSHOT</version>
 	<packaging>pom</packaging>
 	<name>hivesterix</name>
 
diff --git a/hyracks/hyracks-api/pom.xml b/hyracks/hyracks-api/pom.xml
index 0d75de4..6a56532 100644
--- a/hyracks/hyracks-api/pom.xml
+++ b/hyracks/hyracks-api/pom.xml
@@ -19,7 +19,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -61,7 +61,7 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-ipc</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   	</dependency>
   	<dependency>
   		<groupId>org.apache.commons</groupId>
diff --git a/hyracks/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IConnectorDescriptor.java b/hyracks/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IConnectorDescriptor.java
index 56200e4..4638118 100644
--- a/hyracks/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IConnectorDescriptor.java
+++ b/hyracks/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IConnectorDescriptor.java
@@ -111,6 +111,11 @@
             BitSet sourceBitmap);
 
     /**
+     * Indicate whether the connector is an all-producers-to-all-consumers connector
+     */
+    public boolean allProducersToAllConsumers();
+
+    /**
      * Gets the display name.
      */
     public String getDisplayName();
diff --git a/hyracks/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/exceptions/HyracksDataException.java b/hyracks/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/exceptions/HyracksDataException.java
index 6390abf..aab59c8 100644
--- a/hyracks/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/exceptions/HyracksDataException.java
+++ b/hyracks/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/exceptions/HyracksDataException.java
@@ -17,6 +17,8 @@
 public class HyracksDataException extends HyracksException {
     private static final long serialVersionUID = 1L;
 
+    private String nodeId;
+
     public HyracksDataException() {
     }
 
@@ -24,11 +26,19 @@
         super(message);
     }
 
+    public HyracksDataException(Throwable cause) {
+        super(cause);
+    }
+
     public HyracksDataException(String message, Throwable cause) {
         super(message, cause);
     }
 
-    public HyracksDataException(Throwable cause) {
-        super(cause);
+    public void setNodeId(String nodeId) {
+        this.nodeId = nodeId;
+    }
+
+    public String getNodeId() {
+        return nodeId;
     }
 }
\ No newline at end of file
diff --git a/hyracks/hyracks-client/pom.xml b/hyracks/hyracks-client/pom.xml
index 099c178..99ee616 100644
--- a/hyracks/hyracks-client/pom.xml
+++ b/hyracks/hyracks-client/pom.xml
@@ -19,7 +19,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -39,22 +39,22 @@
  <dependency>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks-api</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
  </dependency>
  <dependency>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks-net</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
  </dependency>
  <dependency>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks-comm</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
  </dependency>
   <dependency>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks-dataflow-common</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
  </dependency>
   </dependencies>
 </project>
diff --git a/hyracks/hyracks-client/src/main/java/edu/uci/ics/hyracks/client/dataset/HyracksDatasetReader.java b/hyracks/hyracks-client/src/main/java/edu/uci/ics/hyracks/client/dataset/HyracksDatasetReader.java
index 03432a8..51e4950 100644
--- a/hyracks/hyracks-client/src/main/java/edu/uci/ics/hyracks/client/dataset/HyracksDatasetReader.java
+++ b/hyracks/hyracks-client/src/main/java/edu/uci/ics/hyracks/client/dataset/HyracksDatasetReader.java
@@ -104,8 +104,8 @@
                             getSocketAddress(knownRecords[lastReadPartition]), jobId, resultSetId, lastReadPartition,
                             NUM_READ_BUFFERS);
                     lastMonitor = getMonitor(lastReadPartition);
-                    resultChannel.open(datasetClientCtx);
                     resultChannel.registerMonitor(lastMonitor);
+                    resultChannel.open(datasetClientCtx);
                 } catch (Exception e) {
                     throw new HyracksDataException(e);
                 }
@@ -142,8 +142,8 @@
                                 getSocketAddress(knownRecords[lastReadPartition]), jobId, resultSetId,
                                 lastReadPartition, NUM_READ_BUFFERS);
                         lastMonitor = getMonitor(lastReadPartition);
-                        resultChannel.open(datasetClientCtx);
                         resultChannel.registerMonitor(lastMonitor);
+                        resultChannel.open(datasetClientCtx);
                     } catch (Exception e) {
                         throw new HyracksDataException(e);
                     }
diff --git a/hyracks/hyracks-comm/pom.xml b/hyracks/hyracks-comm/pom.xml
index 6755171..f46971a 100644
--- a/hyracks/hyracks-comm/pom.xml
+++ b/hyracks/hyracks-comm/pom.xml
@@ -19,7 +19,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -39,12 +39,12 @@
  <dependency>
  	<groupId>edu.uci.ics.hyracks</groupId>
  	<artifactId>hyracks-api</artifactId>
- 	<version>0.2.7-SNAPSHOT</version>
+ 	<version>0.2.10-SNAPSHOT</version>
  </dependency>
   <dependency>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks-net</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
  </dependency>
   </dependencies>
 </project>
diff --git a/hyracks/hyracks-control/hyracks-control-cc/pom.xml b/hyracks/hyracks-control/hyracks-control-cc/pom.xml
index a30fd89..17638e8 100644
--- a/hyracks/hyracks-control/hyracks-control-cc/pom.xml
+++ b/hyracks/hyracks-control/hyracks-control-cc/pom.xml
@@ -19,7 +19,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks-control</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -40,7 +40,7 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-control-common</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
diff --git a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/NodeControllerState.java b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/NodeControllerState.java
index 67ba2b6..6785d6f 100644
--- a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/NodeControllerState.java
+++ b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/NodeControllerState.java
@@ -189,36 +189,37 @@
 
     public void notifyHeartbeat(HeartbeatData hbData) {
         lastHeartbeatDuration = 0;
-
         hbTime[rrdPtr] = System.currentTimeMillis();
-        heapInitSize[rrdPtr] = hbData.heapInitSize;
-        heapUsedSize[rrdPtr] = hbData.heapUsedSize;
-        heapCommittedSize[rrdPtr] = hbData.heapCommittedSize;
-        heapMaxSize[rrdPtr] = hbData.heapMaxSize;
-        nonheapInitSize[rrdPtr] = hbData.nonheapInitSize;
-        nonheapUsedSize[rrdPtr] = hbData.nonheapUsedSize;
-        nonheapCommittedSize[rrdPtr] = hbData.nonheapCommittedSize;
-        nonheapMaxSize[rrdPtr] = hbData.nonheapMaxSize;
-        threadCount[rrdPtr] = hbData.threadCount;
-        peakThreadCount[rrdPtr] = hbData.peakThreadCount;
-        systemLoadAverage[rrdPtr] = hbData.systemLoadAverage;
-        int gcN = hbSchema.getGarbageCollectorInfos().length;
-        for (int i = 0; i < gcN; ++i) {
-            gcCollectionCounts[i][rrdPtr] = hbData.gcCollectionCounts[i];
-            gcCollectionTimes[i][rrdPtr] = hbData.gcCollectionTimes[i];
+        if (hbData != null) {
+            heapInitSize[rrdPtr] = hbData.heapInitSize;
+            heapUsedSize[rrdPtr] = hbData.heapUsedSize;
+            heapCommittedSize[rrdPtr] = hbData.heapCommittedSize;
+            heapMaxSize[rrdPtr] = hbData.heapMaxSize;
+            nonheapInitSize[rrdPtr] = hbData.nonheapInitSize;
+            nonheapUsedSize[rrdPtr] = hbData.nonheapUsedSize;
+            nonheapCommittedSize[rrdPtr] = hbData.nonheapCommittedSize;
+            nonheapMaxSize[rrdPtr] = hbData.nonheapMaxSize;
+            threadCount[rrdPtr] = hbData.threadCount;
+            peakThreadCount[rrdPtr] = hbData.peakThreadCount;
+            systemLoadAverage[rrdPtr] = hbData.systemLoadAverage;
+            int gcN = hbSchema.getGarbageCollectorInfos().length;
+            for (int i = 0; i < gcN; ++i) {
+                gcCollectionCounts[i][rrdPtr] = hbData.gcCollectionCounts[i];
+                gcCollectionTimes[i][rrdPtr] = hbData.gcCollectionTimes[i];
+            }
+            netPayloadBytesRead[rrdPtr] = hbData.netPayloadBytesRead;
+            netPayloadBytesWritten[rrdPtr] = hbData.netPayloadBytesWritten;
+            netSignalingBytesRead[rrdPtr] = hbData.netSignalingBytesRead;
+            netSignalingBytesWritten[rrdPtr] = hbData.netSignalingBytesWritten;
+            datasetNetPayloadBytesRead[rrdPtr] = hbData.datasetNetPayloadBytesRead;
+            datasetNetPayloadBytesWritten[rrdPtr] = hbData.datasetNetPayloadBytesWritten;
+            datasetNetSignalingBytesRead[rrdPtr] = hbData.datasetNetSignalingBytesRead;
+            datasetNetSignalingBytesWritten[rrdPtr] = hbData.datasetNetSignalingBytesWritten;
+            ipcMessagesSent[rrdPtr] = hbData.ipcMessagesSent;
+            ipcMessageBytesSent[rrdPtr] = hbData.ipcMessageBytesSent;
+            ipcMessagesReceived[rrdPtr] = hbData.ipcMessagesReceived;
+            ipcMessageBytesReceived[rrdPtr] = hbData.ipcMessageBytesReceived;
         }
-        netPayloadBytesRead[rrdPtr] = hbData.netPayloadBytesRead;
-        netPayloadBytesWritten[rrdPtr] = hbData.netPayloadBytesWritten;
-        netSignalingBytesRead[rrdPtr] = hbData.netSignalingBytesRead;
-        netSignalingBytesWritten[rrdPtr] = hbData.netSignalingBytesWritten;
-        datasetNetPayloadBytesRead[rrdPtr] = hbData.datasetNetPayloadBytesRead;
-        datasetNetPayloadBytesWritten[rrdPtr] = hbData.datasetNetPayloadBytesWritten;
-        datasetNetSignalingBytesRead[rrdPtr] = hbData.datasetNetSignalingBytesRead;
-        datasetNetSignalingBytesWritten[rrdPtr] = hbData.datasetNetSignalingBytesWritten;
-        ipcMessagesSent[rrdPtr] = hbData.ipcMessagesSent;
-        ipcMessageBytesSent[rrdPtr] = hbData.ipcMessageBytesSent;
-        ipcMessagesReceived[rrdPtr] = hbData.ipcMessagesReceived;
-        ipcMessageBytesReceived[rrdPtr] = hbData.ipcMessageBytesReceived;
         rrdPtr = (rrdPtr + 1) % RRD_SIZE;
     }
 
diff --git a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/adminconsole/pages/IndexPage.java b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/adminconsole/pages/IndexPage.java
index e2daff8..cd3ea6e 100644
--- a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/adminconsole/pages/IndexPage.java
+++ b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/adminconsole/pages/IndexPage.java
@@ -69,7 +69,6 @@
                 JSONObject o = item.getModelObject();
                 try {
                     item.add(new Label("job-id", o.getString("job-id")));
-                    item.add(new Label("application-name", o.getString("application-name")));
                     item.add(new Label("status", o.getString("status")));
                     item.add(new Label("create-time", o.getString("create-time")));
                     item.add(new Label("start-time", o.getString("start-time")));
diff --git a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobRun.java b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobRun.java
index 5738907..1f68210 100644
--- a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobRun.java
+++ b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobRun.java
@@ -15,6 +15,8 @@
 package edu.uci.ics.hyracks.control.cc.job;
 
 import java.util.ArrayList;
+import java.io.PrintWriter;
+import java.io.StringWriter;
 import java.util.EnumSet;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -46,6 +48,7 @@
 import edu.uci.ics.hyracks.control.cc.scheduler.ActivityPartitionDetails;
 import edu.uci.ics.hyracks.control.cc.scheduler.JobScheduler;
 import edu.uci.ics.hyracks.control.common.job.profiling.om.JobProfile;
+import edu.uci.ics.hyracks.control.common.utils.ExceptionUtils;
 
 public class JobRun implements IJobStatusConditionVariable {
     private final DeploymentId deploymentId;
@@ -359,7 +362,13 @@
                                 taskAttempt.put("end-time", ta.getEndTime());
                                 List<Exception> exceptions = ta.getExceptions();
                                 if (exceptions != null && !exceptions.isEmpty()) {
-                                    taskAttempt.put("failure-details", exceptions);
+                                    List<Exception> filteredExceptions = ExceptionUtils
+                                            .getActualExceptions(exceptions);
+                                    for (Exception exception : filteredExceptions) {
+                                        StringWriter exceptionWriter = new StringWriter();
+                                        exception.printStackTrace(new PrintWriter(exceptionWriter));
+                                        taskAttempt.put("failure-details", exceptionWriter.toString());
+                                    }
                                 }
                                 taskAttempts.put(taskAttempt);
                             }
@@ -388,4 +397,4 @@
     public Map<OperatorDescriptorId, List<String>> getOperatorLocations() {
         return operatorLocations;
     }
-}
\ No newline at end of file
+}
diff --git a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/ActivityClusterPlanner.java b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/ActivityClusterPlanner.java
index 4d2ad6b..3863eda 100644
--- a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/ActivityClusterPlanner.java
+++ b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/ActivityClusterPlanner.java
@@ -190,18 +190,29 @@
                     ActivityId ac2 = ac.getConsumerActivity(cdId);
                     Task[] ac2TaskStates = activityPlanMap.get(ac2).getTasks();
                     int nConsumers = ac2TaskStates.length;
-                    for (int i = 0; i < nProducers; ++i) {
-                        c.indicateTargetPartitions(nProducers, nConsumers, i, targetBitmap);
-                        List<Pair<TaskId, ConnectorDescriptorId>> cInfoList = taskConnectivity.get(ac1TaskStates[i]
-                                .getTaskId());
-                        if (cInfoList == null) {
-                            cInfoList = new ArrayList<Pair<TaskId, ConnectorDescriptorId>>();
-                            taskConnectivity.put(ac1TaskStates[i].getTaskId(), cInfoList);
-                        }
-                        for (int j = targetBitmap.nextSetBit(0); j >= 0; j = targetBitmap.nextSetBit(j + 1)) {
+                    if (c.allProducersToAllConsumers()) {
+                        List<Pair<TaskId, ConnectorDescriptorId>> cInfoList = new ArrayList<Pair<TaskId, ConnectorDescriptorId>>();
+                        for (int j = 0; j < nConsumers; j++) {
                             TaskId targetTID = ac2TaskStates[j].getTaskId();
                             cInfoList.add(Pair.<TaskId, ConnectorDescriptorId> of(targetTID, cdId));
                         }
+                        for (int i = 0; i < nProducers; ++i) {
+                            taskConnectivity.put(ac1TaskStates[i].getTaskId(), cInfoList);
+                        }
+                    } else {
+                        for (int i = 0; i < nProducers; ++i) {
+                            c.indicateTargetPartitions(nProducers, nConsumers, i, targetBitmap);
+                            List<Pair<TaskId, ConnectorDescriptorId>> cInfoList = taskConnectivity.get(ac1TaskStates[i]
+                                    .getTaskId());
+                            if (cInfoList == null) {
+                                cInfoList = new ArrayList<Pair<TaskId, ConnectorDescriptorId>>();
+                                taskConnectivity.put(ac1TaskStates[i].getTaskId(), cInfoList);
+                            }
+                            for (int j = targetBitmap.nextSetBit(0); j >= 0; j = targetBitmap.nextSetBit(j + 1)) {
+                                TaskId targetTID = ac2TaskStates[j].getTaskId();
+                                cInfoList.add(Pair.<TaskId, ConnectorDescriptorId> of(targetTID, cdId));
+                            }
+                        }
                     }
                 }
             }
@@ -341,9 +352,15 @@
                     int nConsumers = ac2TaskStates.length;
 
                     int[] fanouts = new int[nProducers];
-                    for (int i = 0; i < nProducers; ++i) {
-                        c.indicateTargetPartitions(nProducers, nConsumers, i, targetBitmap);
-                        fanouts[i] = targetBitmap.cardinality();
+                    if (c.allProducersToAllConsumers()) {
+                        for (int i = 0; i < nProducers; ++i) {
+                            fanouts[i] = nConsumers;
+                        }
+                    } else {
+                        for (int i = 0; i < nProducers; ++i) {
+                            c.indicateTargetPartitions(nProducers, nConsumers, i, targetBitmap);
+                            fanouts[i] = targetBitmap.cardinality();
+                        }
                     }
                     IConnectorPolicy cp = assignConnectorPolicy(ac, c, nProducers, nConsumers, fanouts);
                     cPolicyMap.put(cdId, cp);
diff --git a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/JobScheduler.java b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/JobScheduler.java
index d568963..d2c018f 100644
--- a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/JobScheduler.java
+++ b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/JobScheduler.java
@@ -27,6 +27,9 @@
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
+import org.json.JSONException;
+import org.json.JSONObject;
+
 import edu.uci.ics.hyracks.api.constraints.Constraint;
 import edu.uci.ics.hyracks.api.constraints.expressions.LValueConstraintExpression;
 import edu.uci.ics.hyracks.api.constraints.expressions.PartitionLocationExpression;
@@ -46,6 +49,7 @@
 import edu.uci.ics.hyracks.api.util.JavaSerializationUtils;
 import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
 import edu.uci.ics.hyracks.control.cc.NodeControllerState;
+import edu.uci.ics.hyracks.control.cc.application.CCApplicationContext;
 import edu.uci.ics.hyracks.control.cc.job.ActivityClusterPlan;
 import edu.uci.ics.hyracks.control.cc.job.JobRun;
 import edu.uci.ics.hyracks.control.cc.job.Task;
@@ -462,13 +466,14 @@
     private void abortJob(List<Exception> exceptions) {
         Set<TaskCluster> inProgressTaskClustersCopy = new HashSet<TaskCluster>(inProgressTaskClusters);
         for (TaskCluster tc : inProgressTaskClustersCopy) {
-            abortTaskCluster(findLastTaskClusterAttempt(tc));
+            abortTaskCluster(findLastTaskClusterAttempt(tc), TaskClusterAttempt.TaskClusterStatus.ABORTED);
         }
         assert inProgressTaskClusters.isEmpty();
         ccs.getWorkQueue().schedule(new JobCleanupWork(ccs, jobRun.getJobId(), JobStatus.FAILURE, exceptions));
     }
 
-    private void abortTaskCluster(TaskClusterAttempt tcAttempt) {
+    private void abortTaskCluster(TaskClusterAttempt tcAttempt,
+            TaskClusterAttempt.TaskClusterStatus failedOrAbortedStatus) {
         LOGGER.fine("Aborting task cluster: " + tcAttempt.getAttempt());
         Set<TaskAttemptId> abortTaskIds = new HashSet<TaskAttemptId>();
         Map<String, List<TaskAttemptId>> abortTaskAttemptMap = new HashMap<String, List<TaskAttemptId>>();
@@ -481,11 +486,13 @@
                 ta.setStatus(TaskAttempt.TaskStatus.ABORTED, null);
                 ta.setEndTime(System.currentTimeMillis());
                 List<TaskAttemptId> abortTaskAttempts = abortTaskAttemptMap.get(ta.getNodeId());
-                if (abortTaskAttempts == null) {
+                if (status == TaskAttempt.TaskStatus.RUNNING && abortTaskAttempts == null) {
                     abortTaskAttempts = new ArrayList<TaskAttemptId>();
                     abortTaskAttemptMap.put(ta.getNodeId(), abortTaskAttempts);
                 }
-                abortTaskAttempts.add(taId);
+                if (status == TaskAttempt.TaskStatus.RUNNING) {
+                    abortTaskAttempts.add(taId);
+                }
             }
         }
         final JobId jobId = jobRun.getJobId();
@@ -509,6 +516,9 @@
         PartitionMatchMaker pmm = jobRun.getPartitionMatchMaker();
         pmm.removeUncommittedPartitions(tc.getProducedPartitions(), abortTaskIds);
         pmm.removePartitionRequests(tc.getRequiredPartitions(), abortTaskIds);
+
+        tcAttempt.setStatus(failedOrAbortedStatus);
+        tcAttempt.setEndTime(System.currentTimeMillis());
     }
 
     private void abortDoomedTaskClusters() throws HyracksException {
@@ -523,9 +533,7 @@
         for (TaskCluster tc : doomedTaskClusters) {
             TaskClusterAttempt tca = findLastTaskClusterAttempt(tc);
             if (tca != null) {
-                abortTaskCluster(tca);
-                tca.setEndTime(System.currentTimeMillis());
-                tca.setStatus(TaskClusterAttempt.TaskClusterStatus.ABORTED);
+                abortTaskCluster(tca, TaskClusterAttempt.TaskClusterStatus.ABORTED);
             }
         }
     }
@@ -612,9 +620,7 @@
             if (lastAttempt != null && taId.getAttempt() == lastAttempt.getAttempt()) {
                 LOGGER.fine("Marking TaskAttempt " + ta.getTaskAttemptId() + " as failed");
                 ta.setStatus(TaskAttempt.TaskStatus.FAILED, exceptions);
-                abortTaskCluster(lastAttempt);
-                lastAttempt.setStatus(TaskClusterAttempt.TaskClusterStatus.FAILED);
-                lastAttempt.setEndTime(System.currentTimeMillis());
+                abortTaskCluster(lastAttempt, TaskClusterAttempt.TaskClusterStatus.FAILED);
                 abortDoomedTaskClusters();
                 if (lastAttempt.getAttempt() >= jobRun.getActivityClusterGraph().getMaxReattempts()) {
                     abortJob(exceptions);
@@ -639,32 +645,41 @@
     public void notifyNodeFailures(Set<String> deadNodes) {
         try {
             jobRun.getPartitionMatchMaker().notifyNodeFailures(deadNodes);
+            jobRun.getParticipatingNodeIds().removeAll(deadNodes);
+            jobRun.getCleanupPendingNodeIds().removeAll(deadNodes);
+            if (jobRun.getPendingStatus() != null && jobRun.getCleanupPendingNodeIds().isEmpty()) {
+                finishJob(jobRun);
+                return;
+            }
             for (ActivityCluster ac : jobRun.getActivityClusterGraph().getActivityClusterMap().values()) {
-                TaskCluster[] taskClusters = getActivityClusterPlan(ac).getTaskClusters();
-                if (taskClusters != null) {
-                    for (TaskCluster tc : taskClusters) {
-                        TaskClusterAttempt lastTaskClusterAttempt = findLastTaskClusterAttempt(tc);
-                        if (lastTaskClusterAttempt != null
-                                && (lastTaskClusterAttempt.getStatus() == TaskClusterAttempt.TaskClusterStatus.COMPLETED || lastTaskClusterAttempt
-                                        .getStatus() == TaskClusterAttempt.TaskClusterStatus.RUNNING)) {
-                            boolean abort = false;
-                            for (TaskAttempt ta : lastTaskClusterAttempt.getTaskAttempts().values()) {
-                                assert (ta.getStatus() == TaskAttempt.TaskStatus.COMPLETED || ta.getStatus() == TaskAttempt.TaskStatus.RUNNING);
-                                if (deadNodes.contains(ta.getNodeId())) {
-                                    ta.setStatus(
-                                            TaskAttempt.TaskStatus.FAILED,
-                                            Collections.singletonList(new Exception("Node " + ta.getNodeId()
-                                                    + " failed")));
-                                    ta.setEndTime(System.currentTimeMillis());
-                                    abort = true;
+                if (isPlanned(ac)) {
+                    TaskCluster[] taskClusters = getActivityClusterPlan(ac).getTaskClusters();
+                    if (taskClusters != null) {
+                        for (TaskCluster tc : taskClusters) {
+                            TaskClusterAttempt lastTaskClusterAttempt = findLastTaskClusterAttempt(tc);
+                            if (lastTaskClusterAttempt != null
+                                    && (lastTaskClusterAttempt.getStatus() == TaskClusterAttempt.TaskClusterStatus.COMPLETED || lastTaskClusterAttempt
+                                            .getStatus() == TaskClusterAttempt.TaskClusterStatus.RUNNING)) {
+                                boolean abort = false;
+                                for (TaskAttempt ta : lastTaskClusterAttempt.getTaskAttempts().values()) {
+                                    assert (ta.getStatus() == TaskAttempt.TaskStatus.COMPLETED || ta.getStatus() == TaskAttempt.TaskStatus.RUNNING);
+                                    if (deadNodes.contains(ta.getNodeId())) {
+                                        ta.setStatus(
+                                                TaskAttempt.TaskStatus.FAILED,
+                                                Collections.singletonList(new Exception("Node " + ta.getNodeId()
+                                                        + " failed")));
+                                        ta.setEndTime(System.currentTimeMillis());
+                                        abort = true;
+                                    }
+                                }
+                                if (abort) {
+                                    abortTaskCluster(lastTaskClusterAttempt,
+                                            TaskClusterAttempt.TaskClusterStatus.ABORTED);
                                 }
                             }
-                            if (abort) {
-                                abortTaskCluster(lastTaskClusterAttempt);
-                            }
                         }
+                        abortDoomedTaskClusters();
                     }
-                    abortDoomedTaskClusters();
                 }
             }
             startRunnableActivityClusters();
@@ -672,4 +687,37 @@
             abortJob(Collections.singletonList(e));
         }
     }
+
+    private void finishJob(final JobRun run) {
+        JobId jobId = run.getJobId();
+        CCApplicationContext appCtx = ccs.getApplicationContext();
+        if (appCtx != null) {
+            try {
+                appCtx.notifyJobFinish(jobId);
+            } catch (HyracksException e) {
+                e.printStackTrace();
+            }
+        }
+        run.setStatus(run.getPendingStatus(), run.getPendingExceptions());
+        ccs.getActiveRunMap().remove(jobId);
+        ccs.getRunMapArchive().put(jobId, run);
+        ccs.getRunHistory().put(jobId, run.getExceptions());
+        try {
+            ccs.getJobLogFile().log(createJobLogObject(run));
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    private JSONObject createJobLogObject(final JobRun run) {
+        JSONObject jobLogObject = new JSONObject();
+        try {
+            ActivityClusterGraph acg = run.getActivityClusterGraph();
+            jobLogObject.put("activity-cluster-graph", acg.toJSON());
+            jobLogObject.put("job-run", run.toJSON());
+        } catch (JSONException e) {
+            throw new RuntimeException(e);
+        }
+        return jobLogObject;
+    }
 }
\ No newline at end of file
diff --git a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/AbstractHeartbeatWork.java b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/AbstractHeartbeatWork.java
new file mode 100644
index 0000000..7605295
--- /dev/null
+++ b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/AbstractHeartbeatWork.java
@@ -0,0 +1,49 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.control.cc.work;
+
+import java.util.Map;
+
+import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
+import edu.uci.ics.hyracks.control.cc.NodeControllerState;
+import edu.uci.ics.hyracks.control.common.heartbeat.HeartbeatData;
+import edu.uci.ics.hyracks.control.common.work.SynchronizableWork;
+
+public abstract class AbstractHeartbeatWork extends SynchronizableWork {
+
+    private final ClusterControllerService ccs;
+    private final String nodeId;
+    private final HeartbeatData hbData;
+
+    public AbstractHeartbeatWork(ClusterControllerService ccs, String nodeId, HeartbeatData hbData) {
+        this.ccs = ccs;
+        this.nodeId = nodeId;
+        this.hbData = hbData;
+    }
+
+    @Override
+    public void doRun() {
+        Map<String, NodeControllerState> nodeMap = ccs.getNodeMap();
+        NodeControllerState state = nodeMap.get(nodeId);
+        if (state != null) {
+            state.notifyHeartbeat(hbData);
+        }
+        runWork();
+    }
+
+    public abstract void runWork();
+
+}
diff --git a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/AbstractTaskLifecycleWork.java b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/AbstractTaskLifecycleWork.java
index 58aaa57..bcb278b 100644
--- a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/AbstractTaskLifecycleWork.java
+++ b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/AbstractTaskLifecycleWork.java
@@ -29,15 +29,15 @@
 import edu.uci.ics.hyracks.control.cc.job.TaskAttempt;
 import edu.uci.ics.hyracks.control.cc.job.TaskCluster;
 import edu.uci.ics.hyracks.control.cc.job.TaskClusterAttempt;
-import edu.uci.ics.hyracks.control.common.work.AbstractWork;
 
-public abstract class AbstractTaskLifecycleWork extends AbstractWork {
+public abstract class AbstractTaskLifecycleWork extends AbstractHeartbeatWork {
     protected final ClusterControllerService ccs;
     protected final JobId jobId;
     protected final TaskAttemptId taId;
     protected final String nodeId;
 
     public AbstractTaskLifecycleWork(ClusterControllerService ccs, JobId jobId, TaskAttemptId taId, String nodeId) {
+        super(ccs, nodeId, null);
         this.ccs = ccs;
         this.jobId = jobId;
         this.taId = taId;
@@ -45,7 +45,7 @@
     }
 
     @Override
-    public final void run() {
+    public final void runWork() {
         JobRun run = ccs.getActiveRunMap().get(jobId);
         if (run != null) {
             TaskId tid = taId.getTaskId();
diff --git a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/ApplicationMessageWork.java b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/ApplicationMessageWork.java
index bc58d1e..c4d202f 100644
--- a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/ApplicationMessageWork.java
+++ b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/ApplicationMessageWork.java
@@ -22,12 +22,11 @@
 import edu.uci.ics.hyracks.api.messages.IMessage;
 import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
 import edu.uci.ics.hyracks.control.common.deployment.DeploymentUtils;
-import edu.uci.ics.hyracks.control.common.work.AbstractWork;
 
 /**
  * @author rico
  */
-public class ApplicationMessageWork extends AbstractWork {
+public class ApplicationMessageWork extends AbstractHeartbeatWork {
 
     private static final Logger LOGGER = Logger.getLogger(ApplicationMessageWork.class.getName());
     private byte[] message;
@@ -36,6 +35,7 @@
     private ClusterControllerService ccs;
 
     public ApplicationMessageWork(ClusterControllerService ccs, byte[] message, DeploymentId deploymentId, String nodeId) {
+        super(ccs, nodeId, null);
         this.ccs = ccs;
         this.deploymentId = deploymentId;
         this.nodeId = nodeId;
@@ -43,7 +43,7 @@
     }
 
     @Override
-    public void run() {
+    public void runWork() {
         final ICCApplicationContext ctx = ccs.getApplicationContext();
         try {
             final IMessage data = (IMessage) DeploymentUtils.deserialize(message, deploymentId, ctx);
diff --git a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/JobCleanupWork.java b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/JobCleanupWork.java
index 3b29b52..46a7c16 100644
--- a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/JobCleanupWork.java
+++ b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/JobCleanupWork.java
@@ -14,6 +14,7 @@
  */
 package edu.uci.ics.hyracks.control.cc.work;
 
+import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 import java.util.logging.Logger;
@@ -48,46 +49,67 @@
 
     @Override
     public void run() {
+        LOGGER.info("Cleanup for JobRun with id: " + jobId);
         final JobRun run = ccs.getActiveRunMap().get(jobId);
         if (run == null) {
             LOGGER.warning("Unable to find JobRun with id: " + jobId);
             return;
         }
+        if (run.getPendingStatus() != null && run.getCleanupPendingNodeIds().isEmpty()) {
+            finishJob(run);
+            return;
+        }
         if (run.getPendingStatus() != null) {
             LOGGER.warning("Ignoring duplicate cleanup for JobRun with id: " + jobId);
             return;
         }
         Set<String> targetNodes = run.getParticipatingNodeIds();
         run.getCleanupPendingNodeIds().addAll(targetNodes);
-        run.setPendingStatus(status, exceptions);
+        if (run.getPendingStatus() != JobStatus.FAILURE && run.getPendingStatus() != JobStatus.TERMINATED) {
+            run.setPendingStatus(status, exceptions);
+        }
         if (targetNodes != null && !targetNodes.isEmpty()) {
+            Set<String> toDelete = new HashSet<String>();
             for (String n : targetNodes) {
                 NodeControllerState ncs = ccs.getNodeMap().get(n);
                 try {
-                    ncs.getNodeController().cleanUpJoblet(jobId, status);
+                    if (ncs == null) {
+                        toDelete.add(n);
+                    } else {
+                        ncs.getNodeController().cleanUpJoblet(jobId, status);
+                    }
                 } catch (Exception e) {
                     e.printStackTrace();
                 }
             }
+            targetNodes.removeAll(toDelete);
+            run.getCleanupPendingNodeIds().removeAll(toDelete);
+            if (run.getCleanupPendingNodeIds().isEmpty()) {
+                finishJob(run);
+            }
         } else {
-            CCApplicationContext appCtx = ccs.getApplicationContext();
-            if (appCtx != null) {
-                try {
-                    appCtx.notifyJobFinish(jobId);
-                } catch (HyracksException e) {
-                    e.printStackTrace();
-                }
-            }
-            run.setStatus(run.getPendingStatus(), run.getPendingExceptions());
-            ccs.getActiveRunMap().remove(jobId);
-            ccs.getRunMapArchive().put(jobId, run);
-            ccs.getRunHistory().put(jobId, run.getExceptions());
+            finishJob(run);
+        }
+    }
+
+    private void finishJob(final JobRun run) {
+        CCApplicationContext appCtx = ccs.getApplicationContext();
+        if (appCtx != null) {
             try {
-                ccs.getJobLogFile().log(createJobLogObject(run));
-            } catch (Exception e) {
-                throw new RuntimeException(e);
+                appCtx.notifyJobFinish(jobId);
+            } catch (HyracksException e) {
+                e.printStackTrace();
             }
         }
+        run.setStatus(run.getPendingStatus(), run.getPendingExceptions());
+        ccs.getActiveRunMap().remove(jobId);
+        ccs.getRunMapArchive().put(jobId, run);
+        ccs.getRunHistory().put(jobId, run.getExceptions());
+        try {
+            ccs.getJobLogFile().log(createJobLogObject(run));
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
     }
 
     private JSONObject createJobLogObject(final JobRun run) {
diff --git a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/JobletCleanupNotificationWork.java b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/JobletCleanupNotificationWork.java
index 5eb851a..2d6bdea 100644
--- a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/JobletCleanupNotificationWork.java
+++ b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/JobletCleanupNotificationWork.java
@@ -28,9 +28,8 @@
 import edu.uci.ics.hyracks.control.cc.NodeControllerState;
 import edu.uci.ics.hyracks.control.cc.application.CCApplicationContext;
 import edu.uci.ics.hyracks.control.cc.job.JobRun;
-import edu.uci.ics.hyracks.control.common.work.AbstractWork;
 
-public class JobletCleanupNotificationWork extends AbstractWork {
+public class JobletCleanupNotificationWork extends AbstractHeartbeatWork {
     private static final Logger LOGGER = Logger.getLogger(JobletCleanupNotificationWork.class.getName());
 
     private ClusterControllerService ccs;
@@ -38,13 +37,14 @@
     private String nodeId;
 
     public JobletCleanupNotificationWork(ClusterControllerService ccs, JobId jobId, String nodeId) {
+        super(ccs, nodeId, null);
         this.ccs = ccs;
         this.jobId = jobId;
         this.nodeId = nodeId;
     }
 
     @Override
-    public void run() {
+    public void runWork() {
         final JobRun run = ccs.getActiveRunMap().get(jobId);
         Set<String> cleanupPendingNodes = run.getCleanupPendingNodeIds();
         if (!cleanupPendingNodes.remove(nodeId)) {
diff --git a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/NodeHeartbeatWork.java b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/NodeHeartbeatWork.java
index 970a45d..8ef8f66 100644
--- a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/NodeHeartbeatWork.java
+++ b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/NodeHeartbeatWork.java
@@ -14,32 +14,20 @@
  */
 package edu.uci.ics.hyracks.control.cc.work;
 
-import java.util.Map;
 import java.util.logging.Level;
 
 import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
-import edu.uci.ics.hyracks.control.cc.NodeControllerState;
 import edu.uci.ics.hyracks.control.common.heartbeat.HeartbeatData;
-import edu.uci.ics.hyracks.control.common.work.SynchronizableWork;
 
-public class NodeHeartbeatWork extends SynchronizableWork {
-    private final ClusterControllerService ccs;
-    private final String nodeId;
-    private final HeartbeatData hbData;
+public class NodeHeartbeatWork extends AbstractHeartbeatWork {
 
     public NodeHeartbeatWork(ClusterControllerService ccs, String nodeId, HeartbeatData hbData) {
-        this.ccs = ccs;
-        this.nodeId = nodeId;
-        this.hbData = hbData;
+        super(ccs, nodeId, hbData);
     }
 
     @Override
-    protected void doRun() throws Exception {
-        Map<String, NodeControllerState> nodeMap = ccs.getNodeMap();
-        NodeControllerState state = nodeMap.get(nodeId);
-        if (state != null) {
-            state.notifyHeartbeat(hbData);
-        }
+    public void runWork() {
+
     }
 
     @Override
diff --git a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/NotifyDeployBinaryWork.java b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/NotifyDeployBinaryWork.java
index c4c8873..c35f385 100644
--- a/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/NotifyDeployBinaryWork.java
+++ b/hyracks/hyracks-control/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/work/NotifyDeployBinaryWork.java
@@ -19,14 +19,13 @@
 import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
 import edu.uci.ics.hyracks.control.common.deployment.DeploymentRun;
 import edu.uci.ics.hyracks.control.common.deployment.DeploymentStatus;
-import edu.uci.ics.hyracks.control.common.work.AbstractWork;
 
 /***
  * This is the work happens on the CC when CC gets a deployment or undeployment notification status message from one NC.
  * 
  * @author yingyib
  */
-public class NotifyDeployBinaryWork extends AbstractWork {
+public class NotifyDeployBinaryWork extends AbstractHeartbeatWork {
 
     private final ClusterControllerService ccs;
     private final String nodeId;
@@ -35,6 +34,7 @@
 
     public NotifyDeployBinaryWork(ClusterControllerService ccs, DeploymentId deploymentId, String nodeId,
             DeploymentStatus deploymentStatus) {
+        super(ccs, nodeId, null);
         this.ccs = ccs;
         this.nodeId = nodeId;
         this.deploymentId = deploymentId;
@@ -43,7 +43,7 @@
     }
 
     @Override
-    public void run() {
+    public void runWork() {
         /** triggered remotely by a NC to notify that the NC is deployed */
         DeploymentRun dRun = ccs.getDeploymentRun(deploymentId);
         dRun.notifyDeploymentStatus(nodeId, deploymentStatus);
diff --git a/hyracks/hyracks-control/hyracks-control-cc/src/main/resources/edu/uci/ics/hyracks/control/cc/adminconsole/pages/IndexPage.html b/hyracks/hyracks-control/hyracks-control-cc/src/main/resources/edu/uci/ics/hyracks/control/cc/adminconsole/pages/IndexPage.html
index 5810f23..4220932 100644
--- a/hyracks/hyracks-control/hyracks-control-cc/src/main/resources/edu/uci/ics/hyracks/control/cc/adminconsole/pages/IndexPage.html
+++ b/hyracks/hyracks-control/hyracks-control-cc/src/main/resources/edu/uci/ics/hyracks/control/cc/adminconsole/pages/IndexPage.html
@@ -38,9 +38,6 @@
                 <span wicket:id="job-id"></span>
             </td>
             <td>
-                <span wicket:id="application-name"></span>
-            </td>
-            <td>
                 <span wicket:id="status"></span>
             </td>
             <td>
diff --git a/hyracks/hyracks-control/hyracks-control-common/pom.xml b/hyracks/hyracks-control/hyracks-control-common/pom.xml
index 0056e99..1f3c764 100644
--- a/hyracks/hyracks-control/hyracks-control-common/pom.xml
+++ b/hyracks/hyracks-control/hyracks-control-common/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks-control</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -41,7 +41,7 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-api</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
diff --git a/hyracks/hyracks-control/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/dataset/ResultStateSweeper.java b/hyracks/hyracks-control/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/dataset/ResultStateSweeper.java
index 69b560c..5a6d849 100644
--- a/hyracks/hyracks-control/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/dataset/ResultStateSweeper.java
+++ b/hyracks/hyracks-control/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/dataset/ResultStateSweeper.java
@@ -55,6 +55,7 @@
             } catch (InterruptedException e) {
                 LOGGER.severe("Result cleaner thread interrupted, but we continue running it.");
                 // There isn't much we can do really here
+                break; // the interrupt was explicit from another thread. This thread should shut down...
             }
         }
 
diff --git a/hyracks/hyracks-control/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/utils/ExceptionUtils.java b/hyracks/hyracks-control/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/utils/ExceptionUtils.java
new file mode 100644
index 0000000..cbdc6e5
--- /dev/null
+++ b/hyracks/hyracks-control/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/utils/ExceptionUtils.java
@@ -0,0 +1,60 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.common.utils;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+
+/**
+ * @author yingyib
+ */
+public class ExceptionUtils {
+
+    public static List<Exception> getActualExceptions(List<Exception> allExceptions) {
+        List<Exception> exceptions = new ArrayList<Exception>();
+        for (Exception exception : allExceptions) {
+            if (possibleRootCause(exception)) {
+                exceptions.add(exception);
+            }
+        }
+        return exceptions;
+    }
+
+    public static void setNodeIds(Collection<Exception> exceptions, String nodeId) {
+        List<Exception> newExceptions = new ArrayList<Exception>();
+        for (Exception e : exceptions) {
+            HyracksDataException newException = new HyracksDataException(e);
+            newException.setNodeId(nodeId);
+            newExceptions.add(newException);
+        }
+        exceptions.clear();
+        exceptions.addAll(newExceptions);
+    }
+
+    private static boolean possibleRootCause(Throwable exception) {
+        Throwable cause = exception;
+        while ((cause = cause.getCause()) != null) {
+            if (cause instanceof java.lang.InterruptedException
+                    || cause instanceof java.nio.channels.ClosedChannelException) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+}
diff --git a/hyracks/hyracks-control/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/work/WorkQueue.java b/hyracks/hyracks-control/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/work/WorkQueue.java
index f12c981..58e12cf 100644
--- a/hyracks/hyracks-control/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/work/WorkQueue.java
+++ b/hyracks/hyracks-control/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/work/WorkQueue.java
@@ -87,6 +87,7 @@
     private class WorkerThread extends Thread {
         WorkerThread() {
             setDaemon(true);
+            setPriority(MAX_PRIORITY);
         }
 
         @Override
diff --git a/hyracks/hyracks-control/hyracks-control-nc/pom.xml b/hyracks/hyracks-control/hyracks-control-nc/pom.xml
index af384d4..006a07b 100644
--- a/hyracks/hyracks-control/hyracks-control-nc/pom.xml
+++ b/hyracks/hyracks-control/hyracks-control-nc/pom.xml
@@ -19,7 +19,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks-control</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -40,19 +40,19 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-control-common</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-net</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-comm</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   	</dependency>
   </dependencies>
   <reporting>
diff --git a/hyracks/hyracks-control/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/Task.java b/hyracks/hyracks-control/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/Task.java
index 53e5a01..c72ced1 100644
--- a/hyracks/hyracks-control/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/Task.java
+++ b/hyracks/hyracks-control/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/Task.java
@@ -49,6 +49,7 @@
 import edu.uci.ics.hyracks.control.common.job.profiling.counters.Counter;
 import edu.uci.ics.hyracks.control.common.job.profiling.om.PartitionProfile;
 import edu.uci.ics.hyracks.control.common.job.profiling.om.TaskProfile;
+import edu.uci.ics.hyracks.control.common.utils.ExceptionUtils;
 import edu.uci.ics.hyracks.control.nc.io.IOManager;
 import edu.uci.ics.hyracks.control.nc.io.WorkspaceFileFactory;
 import edu.uci.ics.hyracks.control.nc.resources.DefaultDeallocatableRegistry;
@@ -243,6 +244,7 @@
                                 addPendingThread(thread);
                                 String oldName = thread.getName();
                                 thread.setName(displayName + ":" + taskAttemptId + ":" + cIdx);
+                                thread.setPriority(Thread.MIN_PRIORITY);
                                 try {
                                     pushFrames(collector, writer);
                                 } catch (HyracksDataException e) {
@@ -276,7 +278,11 @@
             removePendingThread(ct);
         }
         if (!exceptions.isEmpty()) {
+            for (Exception e : exceptions) {
+                e.printStackTrace();
+            }
             NodeControllerService ncs = joblet.getNodeController();
+            ExceptionUtils.setNodeIds(exceptions, ncs.getId());
             ncs.getWorkQueue().schedule(new NotifyTaskFailureWork(ncs, this, exceptions));
         }
     }
diff --git a/hyracks/hyracks-control/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/work/NotifyTaskFailureWork.java b/hyracks/hyracks-control/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/work/NotifyTaskFailureWork.java
index c4784ff..56379d2 100644
--- a/hyracks/hyracks-control/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/work/NotifyTaskFailureWork.java
+++ b/hyracks/hyracks-control/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/work/NotifyTaskFailureWork.java
@@ -43,6 +43,7 @@
                 dpm.abortReader(jobId);
             }
             ncs.getClusterController().notifyTaskFailure(jobId, task.getTaskAttemptId(), ncs.getId(), exceptions);
+            //exceptions.get(0).printStackTrace();
         } catch (Exception e) {
             e.printStackTrace();
         }
diff --git a/hyracks/hyracks-control/pom.xml b/hyracks/hyracks-control/pom.xml
index a98ffe5..7b43c1f 100644
--- a/hyracks/hyracks-control/pom.xml
+++ b/hyracks/hyracks-control/pom.xml
@@ -21,7 +21,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <modules>
diff --git a/hyracks/hyracks-data/hyracks-data-std/pom.xml b/hyracks/hyracks-data/hyracks-data-std/pom.xml
index 90d0229..0758c9a 100644
--- a/hyracks/hyracks-data/hyracks-data-std/pom.xml
+++ b/hyracks/hyracks-data/hyracks-data-std/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks-data</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -41,7 +41,7 @@
   <dependency>
   	<groupId>edu.uci.ics.hyracks</groupId>
   	<artifactId>hyracks-api</artifactId>
-  	<version>0.2.7-SNAPSHOT</version>
+  	<version>0.2.10-SNAPSHOT</version>
   </dependency>
   </dependencies>
 </project>
diff --git a/hyracks/hyracks-data/pom.xml b/hyracks/hyracks-data/pom.xml
index 32dd51d..a5ffd98 100644
--- a/hyracks/hyracks-data/pom.xml
+++ b/hyracks/hyracks-data/pom.xml
@@ -21,7 +21,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <modules>
diff --git a/hyracks/hyracks-dataflow-common/pom.xml b/hyracks/hyracks-dataflow-common/pom.xml
index 6e270bf..d779ca4 100644
--- a/hyracks/hyracks-dataflow-common/pom.xml
+++ b/hyracks/hyracks-dataflow-common/pom.xml
@@ -19,7 +19,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -40,14 +40,14 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-api</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-data-std</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   	</dependency>
   </dependencies>
 </project>
diff --git a/hyracks/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/io/FrameTupleAccessor.java b/hyracks/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/io/FrameTupleAccessor.java
index ce4c74c..ac44c11 100644
--- a/hyracks/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/io/FrameTupleAccessor.java
+++ b/hyracks/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/io/FrameTupleAccessor.java
@@ -22,6 +22,7 @@
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.comm.util.ByteBufferInputStream;
+import edu.uci.ics.hyracks.dataflow.common.util.IntSerDeUtils;
 
 /**
  * FrameTupleCursor is used to navigate over tuples in a Frame. A frame is
@@ -57,27 +58,28 @@
 
     @Override
     public int getTupleCount() {
-        return buffer.getInt(FrameHelper.getTupleCountOffset(frameSize));
+        return IntSerDeUtils.getInt(buffer.array(), FrameHelper.getTupleCountOffset(frameSize));
     }
 
     @Override
     public int getTupleStartOffset(int tupleIndex) {
-        return tupleIndex == 0 ? 0 : buffer.getInt(FrameHelper.getTupleCountOffset(frameSize) - 4 * tupleIndex);
+        return tupleIndex == 0 ? 0 : IntSerDeUtils.getInt(buffer.array(), FrameHelper.getTupleCountOffset(frameSize)
+                - 4 * tupleIndex);
     }
 
     @Override
     public int getTupleEndOffset(int tupleIndex) {
-        return buffer.getInt(FrameHelper.getTupleCountOffset(frameSize) - 4 * (tupleIndex + 1));
+        return IntSerDeUtils.getInt(buffer.array(), FrameHelper.getTupleCountOffset(frameSize) - 4 * (tupleIndex + 1));
     }
 
     @Override
     public int getFieldStartOffset(int tupleIndex, int fIdx) {
-        return fIdx == 0 ? 0 : buffer.getInt(getTupleStartOffset(tupleIndex) + (fIdx - 1) * 4);
+        return fIdx == 0 ? 0 : IntSerDeUtils.getInt(buffer.array(), getTupleStartOffset(tupleIndex) + (fIdx - 1) * 4);
     }
 
     @Override
     public int getFieldEndOffset(int tupleIndex, int fIdx) {
-        return buffer.getInt(getTupleStartOffset(tupleIndex) + fIdx * 4);
+        return IntSerDeUtils.getInt(buffer.array(), getTupleStartOffset(tupleIndex) + fIdx * 4);
     }
 
     @Override
diff --git a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java b/hyracks/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/util/IntSerDeUtils.java
similarity index 65%
copy from hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
copy to hyracks/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/util/IntSerDeUtils.java
index cde5022..9faef09 100644
--- a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
+++ b/hyracks/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/util/IntSerDeUtils.java
@@ -13,16 +13,13 @@
  * limitations under the License.
  */
 
-package edu.uci.ics.hyracks.storage.am.btree.exceptions;
+package edu.uci.ics.hyracks.dataflow.common.util;
 
-public class BTreeDuplicateKeyException extends BTreeException {
-    private static final long serialVersionUID = 1L;
+public class IntSerDeUtils {
 
-    public BTreeDuplicateKeyException(Exception e) {
-        super(e);
+    public static int getInt(byte[] bytes, int offset) {
+        return ((bytes[offset] & 0xff) << 24) + ((bytes[offset + 1] & 0xff) << 16) + ((bytes[offset + 2] & 0xff) << 8)
+                + ((bytes[offset + 3] & 0xff) << 0);
     }
 
-    public BTreeDuplicateKeyException(String message) {
-        super(message);
-    }
 }
diff --git a/hyracks/hyracks-dataflow-hadoop/pom.xml b/hyracks/hyracks-dataflow-hadoop/pom.xml
index 6468118..5c05956 100644
--- a/hyracks/hyracks-dataflow-hadoop/pom.xml
+++ b/hyracks/hyracks-dataflow-hadoop/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -40,14 +40,14 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-api</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-dataflow-common</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
@@ -67,7 +67,7 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-dataflow-std</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<scope>compile</scope>
   	</dependency>
   </dependencies>
diff --git a/hyracks/hyracks-dataflow-std/pom.xml b/hyracks/hyracks-dataflow-std/pom.xml
index f88e852..dafc03f 100644
--- a/hyracks/hyracks-dataflow-std/pom.xml
+++ b/hyracks/hyracks-dataflow-std/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -41,14 +41,14 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-api</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-dataflow-common</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
diff --git a/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/base/AbstractMToNConnectorDescriptor.java b/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/base/AbstractMToNConnectorDescriptor.java
index 30b2482..df4d296 100644
--- a/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/base/AbstractMToNConnectorDescriptor.java
+++ b/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/base/AbstractMToNConnectorDescriptor.java
@@ -38,4 +38,9 @@
         sourceBitmap.clear();
         sourceBitmap.set(0, nProducerPartitions);
     }
+    
+    @Override
+    public boolean allProducersToAllConsumers(){
+        return true;
+    }
 }
\ No newline at end of file
diff --git a/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/collectors/NonDeterministicChannelReader.java b/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/collectors/NonDeterministicChannelReader.java
index 9a84173..7f447c6 100644
--- a/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/collectors/NonDeterministicChannelReader.java
+++ b/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/collectors/NonDeterministicChannelReader.java
@@ -68,7 +68,7 @@
     }
 
     public void open() throws HyracksDataException {
-        lastReadSender = 0;
+        lastReadSender = -1;
     }
 
     public IInputChannel[] getChannels() {
@@ -77,14 +77,9 @@
 
     public synchronized int findNextSender() throws HyracksDataException {
         while (true) {
-            switch (lastReadSender) {
-                default:
-                    lastReadSender = frameAvailability.nextSetBit(lastReadSender + 1);
-                    if (lastReadSender >= 0) {
-                        break;
-                    }
-                case 0:
-                    lastReadSender = frameAvailability.nextSetBit(0);
+            lastReadSender = frameAvailability.nextSetBit(lastReadSender + 1);
+            if (lastReadSender < 0) {
+                lastReadSender = frameAvailability.nextSetBit(0);
             }
             if (lastReadSender >= 0) {
                 assert availableFrameCounts[lastReadSender] > 0;
diff --git a/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/OneToOneConnectorDescriptor.java b/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/OneToOneConnectorDescriptor.java
index 466fead..20a0ed1 100644
--- a/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/OneToOneConnectorDescriptor.java
+++ b/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/OneToOneConnectorDescriptor.java
@@ -82,4 +82,9 @@
         sourceBitmap.clear();
         sourceBitmap.set(consumerIndex);
     }
+
+    @Override
+    public boolean allProducersToAllConsumers() {
+        return false;
+    }
 }
\ No newline at end of file
diff --git a/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/InMemoryHashJoin.java b/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/InMemoryHashJoin.java
index d02d65c..60e9c40 100644
--- a/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/InMemoryHashJoin.java
+++ b/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/InMemoryHashJoin.java
@@ -119,7 +119,7 @@
                     accessorBuild.reset(buffers.get(bIndex));
                     int c = tpComparator.compare(accessorProbe, i, accessorBuild, tIndex);
                     if (c == 0) {
-                    	boolean predEval = ( (predEvaluator == null) || predEvaluator.evaluate(accessorProbe, i, accessorBuild, tIndex) );
+                    	boolean predEval = evaluatePredicate(i, tIndex);
                     	if(predEval){
                     		matchFound = true;
                             appendToResult(i, tIndex, writer);
@@ -155,6 +155,15 @@
         buffer.position(0);
         buffer.limit(buffer.capacity());
     }
+    
+    private boolean evaluatePredicate(int tIx1, int tIx2){
+    	if(reverseOutputOrder){		//Role Reversal Optimization is triggered
+    		return ( (predEvaluator == null) || predEvaluator.evaluate(accessorBuild, tIx2, accessorProbe, tIx1) );
+    	}
+    	else {
+    		return ( (predEvaluator == null) || predEvaluator.evaluate(accessorProbe, tIx1, accessorBuild, tIx2) );
+    	}
+    }
 
     private void appendToResult(int probeSidetIx, int buildSidetIx, IFrameWriter writer) throws HyracksDataException {
         if (!reverseOutputOrder) {
diff --git a/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/NestedLoopJoin.java b/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/NestedLoopJoin.java
index 2f719fa..979ef59 100644
--- a/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/NestedLoopJoin.java
+++ b/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/NestedLoopJoin.java
@@ -49,6 +49,8 @@
     private final boolean isLeftOuter;
     private final ArrayTupleBuilder nullTupleBuilder;
     private final IPredicateEvaluator predEvaluator;
+    private boolean isReversed;		//Added for handling correct calling for predicate-evaluator upon recursive calls (in OptimizedHybridHashJoin) that cause role-reversal
+
     
     public NestedLoopJoin(IHyracksTaskContext ctx, FrameTupleAccessor accessor0, FrameTupleAccessor accessor1,
             ITuplePairComparator comparators, int memSize, IPredicateEvaluator predEval, boolean isLeftOuter, INullWriter[] nullWriters1)
@@ -63,6 +65,7 @@
         this.outBuffers = new ArrayList<ByteBuffer>();
         this.memSize = memSize;
         this.predEvaluator = predEval;
+        this.isReversed = false;
         this.ctx = ctx;
 
         this.isLeftOuter = isLeftOuter;
@@ -133,7 +136,7 @@
             boolean matchFound = false;
             for (int j = 0; j < tupleCount1; ++j) {
                 int c = compare(accessorOuter, i, accessorInner, j);
-                boolean prdEval = (predEvaluator == null) || (predEvaluator.evaluate(accessorOuter, i, accessorInner, j));
+                boolean prdEval = evaluatePredicate(i, j);
                 if (c == 0 && prdEval) {
                 	matchFound = true;
                     if (!appender.appendConcat(accessorOuter, i, accessorInner, j)) {
@@ -165,6 +168,15 @@
             }
         }
     }
+    
+    private boolean evaluatePredicate(int tIx1, int tIx2){
+    	if(isReversed){		//Role Reversal Optimization is triggered
+    		return ( (predEvaluator == null) || predEvaluator.evaluate(accessorInner, tIx2, accessorOuter, tIx1) );
+    	}
+    	else {
+    		return ( (predEvaluator == null) || predEvaluator.evaluate(accessorOuter, tIx1, accessorInner, tIx2) );
+    	}
+    }
 
     public void closeCache() throws HyracksDataException {
         if (runFileWriter != null) {
@@ -206,4 +218,8 @@
         }
         return 0;
     }
+    
+    public void setIsReversed(boolean b){
+    	this.isReversed = b;
+    }
 }
diff --git a/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/OptimizedHybridHashJoin.java b/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/OptimizedHybridHashJoin.java
index cd32c81..6bc810e 100644
--- a/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/OptimizedHybridHashJoin.java
+++ b/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/OptimizedHybridHashJoin.java
@@ -99,6 +99,7 @@
     private int freeFramesCounter; //Used for partition tuning
     
     private boolean isTableEmpty;	//Added for handling the case, where build side is empty (tableSize is 0)
+    private boolean isReversed;		//Added for handling correct calling for predicate-evaluator upon recursive calls that cause role-reversal
     
     public OptimizedHybridHashJoin(IHyracksTaskContext ctx, int memForJoin, int numOfPartitions, String rel0Name,
             String rel1Name, int[] keys0, int[] keys1, IBinaryComparator[] comparators, RecordDescriptor buildRd,
@@ -125,6 +126,7 @@
         this.predEvaluator = predEval;
         this.isLeftOuter = false;
         this.nullWriters1 = null;
+        this.isReversed = false;
 
     }
 
@@ -153,7 +155,8 @@
         
         this.predEvaluator = predEval;
         this.isLeftOuter = isLeftOuter;
-
+        this.isReversed = false;
+        
         this.nullWriters1 = isLeftOuter ? new INullWriter[nullWriterFactories1.length] : null;
         if (isLeftOuter) {
             for (int i = 0; i < nullWriterFactories1.length; i++) {
@@ -441,7 +444,7 @@
         this.inMemJoiner = new InMemoryHashJoin(ctx, inMemTupCount,
                 new FrameTupleAccessor(ctx.getFrameSize(), probeRd), probeHpc, new FrameTupleAccessor(
                         ctx.getFrameSize(), buildRd), buildHpc, new FrameTuplePairComparator(probeKeys, buildKeys,
-                        comparators), isLeftOuter, nullWriters1, table, predEvaluator);
+                        comparators), isLeftOuter, nullWriters1, table, predEvaluator, isReversed);
     }
 
     private void cacheInMemJoin() throws HyracksDataException {
@@ -639,4 +642,8 @@
     public boolean isTableEmpty() {
         return this.isTableEmpty;
     }
+    
+    public void setIsReversed(boolean b){
+    	this.isReversed = b;
+    }
 }
diff --git a/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/OptimizedHybridHashJoinOperatorDescriptor.java b/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/OptimizedHybridHashJoinOperatorDescriptor.java
index 95b7a3c..4e9376d 100644
--- a/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/OptimizedHybridHashJoinOperatorDescriptor.java
+++ b/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/OptimizedHybridHashJoinOperatorDescriptor.java
@@ -19,6 +19,8 @@
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.util.BitSet;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.ActivityId;
@@ -117,6 +119,8 @@
     
     private final boolean isLeftOuter;
     private final INullWriterFactory[] nullWriterFactories1;
+    
+    private static final Logger LOGGER = Logger.getLogger(OptimizedHybridHashJoinOperatorDescriptor.class.getName());
 
     public OptimizedHybridHashJoinOperatorDescriptor(IOperatorDescriptorRegistry spec, int memsize, int inputsize0,
             double factor, int[] keys0, int[] keys1, IBinaryHashFunctionFamily[] hashFunctionGeneratorFactories,
@@ -139,8 +143,6 @@
         this.predEvaluatorFactory = predEvaluatorFactory;
         this.isLeftOuter = isLeftOuter;
         this.nullWriterFactories1 = nullWriterFactories1;
-        
-
     }
 
     public OptimizedHybridHashJoinOperatorDescriptor(IOperatorDescriptorRegistry spec, int memsize, int inputsize0,
@@ -207,7 +209,7 @@
     }
 
     public static class BuildAndPartitionTaskState extends AbstractStateObject {
-
+    	
         private int memForJoin;
         private int numOfPartitions;
         private OptimizedHybridHashJoin hybridHJ;
@@ -303,6 +305,7 @@
                 public void close() throws HyracksDataException {
                     state.hybridHJ.closeBuild();
                     ctx.setStateObject(state);
+                    LOGGER.log(Level.FINE, "OptimizedHybridHashJoin closed its build phase");
                 }
 
                 @Override
@@ -323,7 +326,7 @@
      * Hybrid Hash Join recursively on them.
      */
     private class ProbeAndJoinActivityNode extends AbstractActivityNode {
-
+    	
         private static final long serialVersionUID = 1L;
 
         private final ActivityId buildAid;
@@ -423,9 +426,11 @@
                             hashFunctionGeneratorFactories).createPartitioner(level);
                     ITuplePartitionComputer buildHpc = new FieldHashPartitionComputerFamily(buildKeys,
                             hashFunctionGeneratorFactories).createPartitioner(level);
-
+                    
                     long buildPartSize = ohhj.getBuildPartitionSize(pid) / ctx.getFrameSize();
                     long probePartSize = ohhj.getProbePartitionSize(pid) / ctx.getFrameSize();
+                    
+                    LOGGER.log(Level.FINE,"Joining Partition Pairs (pid "+pid+") - (level "+level+") - BuildSize:\t"+buildPartSize+"\tProbeSize:\t"+probePartSize+" - MemForJoin "+(state.memForJoin));
 
                     //Apply in-Mem HJ if possible
                     if ((buildPartSize < state.memForJoin) || (probePartSize < state.memForJoin)) {
@@ -460,7 +465,7 @@
                     else {
                         OptimizedHybridHashJoin rHHj;
                         if (isLeftOuter || buildPartSize < probePartSize) { //Build Side is smaller
-
+                        	LOGGER.log(Level.FINE,"\tApply RecursiveHHJ for (pid "+pid+") - (level "+level+") [buildSize is smaller]");
                             int n = getNumberOfPartitions(state.memForJoin, (int) buildPartSize, fudgeFactor,
                                     nPartitions);
                            
@@ -503,6 +508,7 @@
                                 }
 
                             } else { //Switch to NLJ (Further recursion seems not to be useful)
+                            	LOGGER.log(Level.FINE,"\tSwitched to NLJ for (pid "+pid+") - (level "+level+") (reverse false) [coming from buildSize was smaller]");
                                 for (int rPid = rPStatus.nextSetBit(0); rPid >= 0; rPid = rPStatus.nextSetBit(rPid + 1)) {
                                     RunFileReader rbrfw = rHHj.getBuildRFReader(rPid);
                                     RunFileReader rprfw = rHHj.getProbeRFReader(rPid);
@@ -515,19 +521,21 @@
                                     int probeSideInTups = rHHj.getProbePartitionSizeInTup(rPid);
                                     if (isLeftOuter || buildSideInTups < probeSideInTups) {
                                         applyNestedLoopJoin(probeRd, buildRd, state.memForJoin, rbrfw, rprfw,
-                                                nljComparator0);
+                                                nljComparator0, false);
                                     } else {
                                         applyNestedLoopJoin(buildRd, probeRd, state.memForJoin, rprfw, rbrfw,
-                                                nljComparator1);
+                                                nljComparator1, false);
                                     }
                                 }
                             }
                         } else { //Role Reversal (Probe Side is smaller)
+                        	LOGGER.log(Level.FINE,"\tApply RecursiveHHJ for (pid "+pid+") - (level "+level+") WITH REVERSAL [probeSize is smaller]");
                             int n = getNumberOfPartitions(state.memForJoin, (int) probePartSize, fudgeFactor,
                                     nPartitions);
                             
                             rHHj = new OptimizedHybridHashJoin(ctx, state.memForJoin, n, BUILD_REL, PROBE_REL,
                                     buildKeys, probeKeys, comparators, buildRd, probeRd, buildHpc, probeHpc, predEvaluator);
+                            rHHj.setIsReversed(true);	//Added to use predicateEvaluator (for inMemoryHashJoin) correctly
 
                             probeSideReader.open();
                             rHHj.initBuild();
@@ -561,7 +569,8 @@
                                     joinPartitionPair(rHHj, rprfw, rbrfw, rPid, afterMax, (level + 1));
                                 }
                             } else { //Switch to NLJ (Further recursion seems not to be effective)
-                                for (int rPid = rPStatus.nextSetBit(0); rPid >= 0; rPid = rPStatus.nextSetBit(rPid + 1)) {
+                            	LOGGER.log(Level.FINE,"\tSwitched to NLJ for (pid "+pid+") - (level "+level+") (reverse true) [coming from probeSize was smaller]");
+                            	for (int rPid = rPStatus.nextSetBit(0); rPid >= 0; rPid = rPStatus.nextSetBit(rPid + 1)) {
                                     RunFileReader rbrfw = rHHj.getBuildRFReader(rPid);
                                     RunFileReader rprfw = rHHj.getProbeRFReader(rPid);
                                     
@@ -573,10 +582,10 @@
                                     long probeSideSize = rprfw.getFileSize();
                                     if (buildSideSize > probeSideSize) {
                                         applyNestedLoopJoin(buildRd, probeRd, state.memForJoin, rbrfw, rprfw,
-                                                nljComparator1);
+                                                nljComparator1, true);
                                     } else {
                                         applyNestedLoopJoin(probeRd, buildRd, state.memForJoin, rprfw, rbrfw,
-                                                nljComparator0);
+                                                nljComparator0, true);
                                     }
                                 }
                             }
@@ -590,7 +599,7 @@
                         RecordDescriptor probeRDesc, ITuplePartitionComputer hpcRepLarger,
                         ITuplePartitionComputer hpcRepSmaller, RunFileReader bReader, RunFileReader pReader, boolean reverse, int pid)
                         throws HyracksDataException {
-
+                	LOGGER.log(Level.FINE,"\t(pid "+pid+") - applyInMemHashJoin (reversal "+reverse+")");
                     ISerializableTable table = new SerializableHashTable(tabSize, ctx);
                     InMemoryHashJoin joiner = new InMemoryHashJoin(ctx, tabSize, new FrameTupleAccessor(
                             ctx.getFrameSize(), probeRDesc), hpcRepLarger, new FrameTupleAccessor(ctx.getFrameSize(),
@@ -619,9 +628,9 @@
                 }
 
                 private void applyNestedLoopJoin(RecordDescriptor outerRd, RecordDescriptor innerRd, int memorySize,
-                        RunFileReader outerReader, RunFileReader innerReader, ITuplePairComparator nljComparator)
+                        RunFileReader outerReader, RunFileReader innerReader, ITuplePairComparator nljComparator, boolean reverse)
                         throws HyracksDataException {
-
+                	
                     NestedLoopJoin nlj = new NestedLoopJoin(ctx, new FrameTupleAccessor(ctx.getFrameSize(), outerRd),
                             new FrameTupleAccessor(ctx.getFrameSize(), innerRd), nljComparator, memorySize, predEvaluator, false, null);
 
diff --git a/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/MaterializingOperatorDescriptor.java b/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/MaterializingOperatorDescriptor.java
index ac5a627..89c20d6 100644
--- a/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/MaterializingOperatorDescriptor.java
+++ b/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/MaterializingOperatorDescriptor.java
@@ -19,6 +19,7 @@
 import java.io.IOException;
 import java.nio.ByteBuffer;
 
+import edu.uci.ics.hyracks.api.comm.IFrameWriter;
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.ActivityId;
 import edu.uci.ics.hyracks.api.dataflow.IActivityGraphBuilder;
@@ -36,6 +37,7 @@
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractOperatorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractStateObject;
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractUnaryInputSinkOperatorNodePushable;
+import edu.uci.ics.hyracks.dataflow.std.base.AbstractUnaryInputUnaryOutputOperatorNodePushable;
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractUnaryOutputSourceOperatorNodePushable;
 
 public class MaterializingOperatorDescriptor extends AbstractOperatorDescriptor {
@@ -43,24 +45,43 @@
 
     private final static int MATERIALIZER_ACTIVITY_ID = 0;
     private final static int READER_ACTIVITY_ID = 1;
+    private final static int MATERIALIZER_READER_ACTIVITY_ID = 2;
+
+    private boolean isSingleActivity;
 
     public MaterializingOperatorDescriptor(IOperatorDescriptorRegistry spec, RecordDescriptor recordDescriptor) {
+        this(spec, recordDescriptor, false);
+    }
+
+    public MaterializingOperatorDescriptor(IOperatorDescriptorRegistry spec, RecordDescriptor recordDescriptor,
+            boolean isSingleActivity) {
         super(spec, 1, 1);
         recordDescriptors[0] = recordDescriptor;
+        this.isSingleActivity = isSingleActivity;
     }
 
     @Override
     public void contributeActivities(IActivityGraphBuilder builder) {
-        MaterializerActivityNode ma = new MaterializerActivityNode(new ActivityId(odId, MATERIALIZER_ACTIVITY_ID));
-        ReaderActivityNode ra = new ReaderActivityNode(new ActivityId(odId, READER_ACTIVITY_ID));
+        if (isSingleActivity) {
+            MaterializerReaderActivityNode mra = new MaterializerReaderActivityNode(new ActivityId(odId,
+                    MATERIALIZER_READER_ACTIVITY_ID));
 
-        builder.addActivity(this, ma);
-        builder.addSourceEdge(0, ma, 0);
+            builder.addActivity(this, mra);
+            builder.addSourceEdge(0, mra, 0);
+            builder.addTargetEdge(0, mra, 0);
+        } else {
+            MaterializerActivityNode ma = new MaterializerActivityNode(new ActivityId(odId, MATERIALIZER_ACTIVITY_ID));
+            ReaderActivityNode ra = new ReaderActivityNode(new ActivityId(odId, READER_ACTIVITY_ID));
 
-        builder.addActivity(this, ra);
-        builder.addTargetEdge(0, ra, 0);
+            builder.addActivity(this, ma);
+            builder.addSourceEdge(0, ma, 0);
 
-        builder.addBlockingEdge(ma, ra);
+            builder.addActivity(this, ra);
+            builder.addTargetEdge(0, ra, 0);
+
+            builder.addBlockingEdge(ma, ra);
+        }
+
     }
 
     public static class MaterializerTaskState extends AbstractStateObject {
@@ -82,6 +103,76 @@
         public void fromBytes(DataInput in) throws IOException {
 
         }
+
+        public void open(IHyracksTaskContext ctx) throws HyracksDataException {
+            FileReference file = ctx.getJobletContext().createManagedWorkspaceFile(
+                    MaterializingOperatorDescriptor.class.getSimpleName());
+            out = new RunFileWriter(file, ctx.getIOManager());
+            out.open();
+        }
+
+        public void appendFrame(ByteBuffer buffer) throws HyracksDataException {
+            out.nextFrame(buffer);
+        }
+
+        public void writeOut(IFrameWriter writer, ByteBuffer frame) throws HyracksDataException {
+            RunFileReader in = out.createReader();
+            writer.open();
+            try {
+                in.open();
+                while (in.nextFrame(frame)) {
+                    frame.flip();
+                    writer.nextFrame(frame);
+                    frame.clear();
+                }
+                in.close();
+            } catch (Exception e) {
+                writer.fail();
+                throw new HyracksDataException(e);
+            } finally {
+                writer.close();
+            }
+        }
+    }
+
+    private final class MaterializerReaderActivityNode extends AbstractActivityNode {
+        private static final long serialVersionUID = 1L;
+
+        public MaterializerReaderActivityNode(ActivityId id) {
+            super(id);
+        }
+
+        @Override
+        public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx,
+                IRecordDescriptorProvider recordDescProvider, final int partition, int nPartitions) {
+            return new AbstractUnaryInputUnaryOutputOperatorNodePushable() {
+                private MaterializerTaskState state;
+
+                @Override
+                public void open() throws HyracksDataException {
+                    state = new MaterializerTaskState(ctx.getJobletContext().getJobId(), new TaskId(getActivityId(),
+                            partition));
+                    state.open(ctx);
+                }
+
+                @Override
+                public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
+                    state.appendFrame(buffer);
+                }
+
+                @Override
+                public void fail() throws HyracksDataException {
+                }
+
+                @Override
+                public void close() throws HyracksDataException {
+                    state.out.close();
+                    ByteBuffer frame = ctx.allocateFrame();
+                    state.writeOut(writer, frame);
+                }
+
+            };
+        }
     }
 
     private final class MaterializerActivityNode extends AbstractActivityNode {
@@ -101,15 +192,12 @@
                 public void open() throws HyracksDataException {
                     state = new MaterializerTaskState(ctx.getJobletContext().getJobId(), new TaskId(getActivityId(),
                             partition));
-                    FileReference file = ctx.getJobletContext().createManagedWorkspaceFile(
-                            MaterializingOperatorDescriptor.class.getSimpleName());
-                    state.out = new RunFileWriter(file, ctx.getIOManager());
-                    state.out.open();
+                    state.open(ctx);
                 }
 
                 @Override
                 public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
-                    state.out.nextFrame(buffer);
+                    state.appendFrame(buffer);
                 }
 
                 @Override
@@ -141,22 +229,7 @@
                     ByteBuffer frame = ctx.allocateFrame();
                     MaterializerTaskState state = (MaterializerTaskState) ctx.getStateObject(new TaskId(new ActivityId(
                             getOperatorId(), MATERIALIZER_ACTIVITY_ID), partition));
-                    RunFileReader in = state.out.createReader();
-                    writer.open();
-                    try {
-                        in.open();
-                        while (in.nextFrame(frame)) {
-                            frame.flip();
-                            writer.nextFrame(frame);
-                            frame.clear();
-                        }
-                        in.close();
-                    } catch (Exception e) {
-                        writer.fail();
-                        throw new HyracksDataException(e);
-                    } finally {
-                        writer.close();
-                    }
+                    state.writeOut(writer, frame);
                 }
 
                 @Override
diff --git a/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/sort/FrameSorter.java b/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/sort/FrameSorter.java
index db70a62..a6bb4e2 100644
--- a/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/sort/FrameSorter.java
+++ b/hyracks/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/sort/FrameSorter.java
@@ -29,6 +29,7 @@
 import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAccessor;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAppender;
 import edu.uci.ics.hyracks.dataflow.common.comm.util.FrameUtils;
+import edu.uci.ics.hyracks.dataflow.common.util.IntSerDeUtils;
 
 public class FrameSorter {
     private final IHyracksTaskContext ctx;
@@ -46,6 +47,7 @@
 
     private int dataFrameCount;
     private int[] tPointers;
+    private int[] tPointersTemp;
     private int tupleCount;
 
     public FrameSorter(IHyracksTaskContext ctx, int[] sortFields,
@@ -116,7 +118,8 @@
             }
         }
         if (tupleCount > 0) {
-            sort(tPointers, 0, tupleCount);
+            tPointersTemp = new int[tPointers.length];
+            sort(0, tupleCount);
         }
     }
 
@@ -142,75 +145,73 @@
         }
     }
 
-    private void sort(int[] tPointers, int offset, int length) {
-        int m = offset + (length >> 1);
-        int mi = tPointers[m * 4];
-        int mj = tPointers[m * 4 + 1];
-        int mv = tPointers[m * 4 + 3];
-
-        int a = offset;
-        int b = a;
-        int c = offset + length - 1;
-        int d = c;
-        while (true) {
-            while (b <= c) {
-                int cmp = compare(tPointers, b, mi, mj, mv);
-                if (cmp > 0) {
-                    break;
+    private void sort(int offset, int length) {
+        int step = 1;
+        int len = length;
+        int end = offset + len;
+        /** bottom-up merge */
+        while (step < len) {
+            /** merge */
+            for (int i = offset; i < end; i += 2 * step) {
+                int next = i + step;
+                if (next < end) {
+                    merge(i, next, step, Math.min(step, end - next));
+                } else {
+                    System.arraycopy(tPointers, i * 4, tPointersTemp, i * 4, (end - i) * 4);
                 }
-                if (cmp == 0) {
-                    swap(tPointers, a++, b);
-                }
-                ++b;
             }
-            while (c >= b) {
-                int cmp = compare(tPointers, c, mi, mj, mv);
-                if (cmp < 0) {
-                    break;
-                }
-                if (cmp == 0) {
-                    swap(tPointers, c, d--);
-                }
-                --c;
+            /** prepare next phase merge */
+            step *= 2;
+            int[] tmp = tPointersTemp;
+            tPointersTemp = tPointers;
+            tPointers = tmp;
+        }
+    }
+
+    /** Merge two subarrays into one */
+    private void merge(int start1, int start2, int len1, int len2) {
+        int targetPos = start1;
+        int pos1 = start1;
+        int pos2 = start2;
+        int end1 = start1 + len1 - 1;
+        int end2 = start2 + len2 - 1;
+        while (pos1 <= end1 && pos2 <= end2) {
+            int cmp = compare(pos1, pos2);
+            if (cmp <= 0) {
+                copy(pos1, targetPos);
+                pos1++;
+            } else {
+                copy(pos2, targetPos);
+                pos2++;
             }
-            if (b > c)
-                break;
-            swap(tPointers, b++, c--);
+            targetPos++;
         }
-
-        int s;
-        int n = offset + length;
-        s = Math.min(a - offset, b - a);
-        vecswap(tPointers, offset, b - s, s);
-        s = Math.min(d - c, n - d - 1);
-        vecswap(tPointers, b, n - s, s);
-
-        if ((s = b - a) > 1) {
-            sort(tPointers, offset, s);
+        if (pos1 <= end1) {
+            int rest = end1 - pos1 + 1;
+            System.arraycopy(tPointers, pos1 * 4, tPointersTemp, targetPos * 4, rest * 4);
         }
-        if ((s = d - c) > 1) {
-            sort(tPointers, n - s, s);
+        if (pos2 <= end2) {
+            int rest = end2 - pos2 + 1;
+            System.arraycopy(tPointers, pos2 * 4, tPointersTemp, targetPos * 4, rest * 4);
         }
     }
 
-    private void swap(int x[], int a, int b) {
-        for (int i = 0; i < 4; ++i) {
-            int t = x[a * 4 + i];
-            x[a * 4 + i] = x[b * 4 + i];
-            x[b * 4 + i] = t;
-        }
+    private void copy(int src, int dest) {
+        tPointersTemp[dest * 4] = tPointers[src * 4];
+        tPointersTemp[dest * 4 + 1] = tPointers[src * 4 + 1];
+        tPointersTemp[dest * 4 + 2] = tPointers[src * 4 + 2];
+        tPointersTemp[dest * 4 + 3] = tPointers[src * 4 + 3];
     }
 
-    private void vecswap(int x[], int a, int b, int n) {
-        for (int i = 0; i < n; i++, a++, b++) {
-            swap(x, a, b);
-        }
-    }
-
-    private int compare(int[] tPointers, int tp1, int tp2i, int tp2j, int tp2v) {
+    private int compare(int tp1, int tp2) {
         int i1 = tPointers[tp1 * 4];
         int j1 = tPointers[tp1 * 4 + 1];
         int v1 = tPointers[tp1 * 4 + 3];
+
+        int tp2i = tPointers[tp2 * 4];
+        int tp2j = tPointers[tp2 * 4 + 1];
+        int tp2v = tPointers[tp2 * 4 + 3];
+
         if (v1 != tp2v) {
             return ((((long) v1) & 0xffffffffL) < (((long) tp2v) & 0xffffffffL)) ? -1 : 1;
         }
@@ -224,12 +225,12 @@
         fta2.reset(buf2);
         for (int f = 0; f < comparators.length; ++f) {
             int fIdx = sortFields[f];
-            int f1Start = fIdx == 0 ? 0 : buf1.getInt(j1 + (fIdx - 1) * 4);
-            int f1End = buf1.getInt(j1 + fIdx * 4);
+            int f1Start = fIdx == 0 ? 0 : IntSerDeUtils.getInt(buf1.array(), j1 + (fIdx - 1) * 4);
+            int f1End = IntSerDeUtils.getInt(buf1.array(), j1 + fIdx * 4);
             int s1 = j1 + fta1.getFieldSlotsLength() + f1Start;
             int l1 = f1End - f1Start;
-            int f2Start = fIdx == 0 ? 0 : buf2.getInt(j2 + (fIdx - 1) * 4);
-            int f2End = buf2.getInt(j2 + fIdx * 4);
+            int f2Start = fIdx == 0 ? 0 : IntSerDeUtils.getInt(buf2.array(), j2 + (fIdx - 1) * 4);
+            int f2End = IntSerDeUtils.getInt(buf2.array(), j2 + fIdx * 4);
             int s2 = j2 + fta2.getFieldSlotsLength() + f2Start;
             int l2 = f2End - f2Start;
             int c = comparators[f].compare(b1, s1, l1, b2, s2, l2);
diff --git a/hyracks/hyracks-dist/pom.xml b/hyracks/hyracks-dist/pom.xml
index 7e9526b..ab7ea53 100755
--- a/hyracks/hyracks-dist/pom.xml
+++ b/hyracks/hyracks-dist/pom.xml
@@ -18,7 +18,7 @@
 	<parent>
 		<artifactId>hyracks</artifactId>
 		<groupId>edu.uci.ics.hyracks</groupId>
-		<version>0.2.7-SNAPSHOT</version>
+		<version>0.2.10-SNAPSHOT</version>
 	</parent>
 
 	<artifactId>hyracks-dist</artifactId>
diff --git a/hyracks/hyracks-documentation/pom.xml b/hyracks/hyracks-documentation/pom.xml
index a814994..4bc3f25 100644
--- a/hyracks/hyracks-documentation/pom.xml
+++ b/hyracks/hyracks-documentation/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
diff --git a/hyracks/hyracks-examples/btree-example/btreeclient/pom.xml b/hyracks/hyracks-examples/btree-example/btreeclient/pom.xml
index 0a5331f..27ab200 100644
--- a/hyracks/hyracks-examples/btree-example/btreeclient/pom.xml
+++ b/hyracks/hyracks-examples/btree-example/btreeclient/pom.xml
@@ -20,26 +20,26 @@
   <parent>
     <groupId>edu.uci.ics.hyracks.examples</groupId>
     <artifactId>btree-example</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <dependencies>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-dataflow-std</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-btree</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks.examples.btree</groupId>
   		<artifactId>btreehelper</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
diff --git a/hyracks/hyracks-examples/btree-example/btreehelper/pom.xml b/hyracks/hyracks-examples/btree-example/btreehelper/pom.xml
index 3d701ce..85eadf1 100644
--- a/hyracks/hyracks-examples/btree-example/btreehelper/pom.xml
+++ b/hyracks/hyracks-examples/btree-example/btreehelper/pom.xml
@@ -20,32 +20,32 @@
   <parent>
     <groupId>edu.uci.ics.hyracks.examples</groupId>
     <artifactId>btree-example</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <dependencies>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-dataflow-std</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-btree</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-api</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-data-std</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   	</dependency>
   </dependencies>
   <build>
diff --git a/hyracks/hyracks-examples/btree-example/btreeserver/pom.xml b/hyracks/hyracks-examples/btree-example/btreeserver/pom.xml
index fef46d8..3d3dc73 100644
--- a/hyracks/hyracks-examples/btree-example/btreeserver/pom.xml
+++ b/hyracks/hyracks-examples/btree-example/btreeserver/pom.xml
@@ -16,13 +16,13 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>edu.uci.ics.hyracks.examples.btree</groupId>
   <artifactId>btreeserver</artifactId>
-  <version>0.2.7-SNAPSHOT</version>
+  <version>0.2.10-SNAPSHOT</version>
   <name>btreeserver</name>
 
   <parent>
     <groupId>edu.uci.ics.hyracks.examples</groupId>
     <artifactId>btree-example</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -77,20 +77,20 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks.examples.btree</groupId>
   		<artifactId>btreehelper</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-control-cc</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-control-nc</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
diff --git a/hyracks/hyracks-examples/btree-example/pom.xml b/hyracks/hyracks-examples/btree-example/pom.xml
index dc3293d..dcab262 100644
--- a/hyracks/hyracks-examples/btree-example/pom.xml
+++ b/hyracks/hyracks-examples/btree-example/pom.xml
@@ -22,7 +22,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks-examples</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <modules>
diff --git a/hyracks/hyracks-examples/hadoop-compat-example/hadoopcompatclient/pom.xml b/hyracks/hyracks-examples/hadoop-compat-example/hadoopcompatclient/pom.xml
index f18d6bf..b5dd798 100644
--- a/hyracks/hyracks-examples/hadoop-compat-example/hadoopcompatclient/pom.xml
+++ b/hyracks/hyracks-examples/hadoop-compat-example/hadoopcompatclient/pom.xml
@@ -21,20 +21,20 @@
   <parent>
     <groupId>edu.uci.ics.hyracks.examples</groupId>
     <artifactId>hadoop-compat-example</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <dependencies>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-dataflow-std</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks.examples.compat</groupId>
   		<artifactId>hadoopcompathelper</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
diff --git a/hyracks/hyracks-examples/hadoop-compat-example/hadoopcompathelper/pom.xml b/hyracks/hyracks-examples/hadoop-compat-example/hadoopcompathelper/pom.xml
index fb595fd..2b703b2 100644
--- a/hyracks/hyracks-examples/hadoop-compat-example/hadoopcompathelper/pom.xml
+++ b/hyracks/hyracks-examples/hadoop-compat-example/hadoopcompathelper/pom.xml
@@ -21,20 +21,20 @@
   <parent>
     <groupId>edu.uci.ics.hyracks.examples</groupId>
     <artifactId>hadoop-compat-example</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <dependencies>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-dataflow-std</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-api</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<scope>compile</scope>
   	</dependency>
   </dependencies>
diff --git a/hyracks/hyracks-examples/hadoop-compat-example/hadoopcompatserver/pom.xml b/hyracks/hyracks-examples/hadoop-compat-example/hadoopcompatserver/pom.xml
index d2062d3..ba30424 100644
--- a/hyracks/hyracks-examples/hadoop-compat-example/hadoopcompatserver/pom.xml
+++ b/hyracks/hyracks-examples/hadoop-compat-example/hadoopcompatserver/pom.xml
@@ -16,13 +16,13 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>edu.uci.ics.hyracks.examples.compat</groupId>
   <artifactId>hadoopcompatserver</artifactId>
-  <version>0.2.7-SNAPSHOT</version>
+  <version>0.2.10-SNAPSHOT</version>
   <name>hadoopcompatserver</name>
 
   <parent>
     <groupId>edu.uci.ics.hyracks.examples</groupId>
     <artifactId>hadoop-compat-example</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -74,7 +74,7 @@
       <plugin>
       	<groupId>edu.uci.ics.hyracks</groupId>
       	<artifactId>hyracks-virtualcluster-maven-plugin</artifactId>
-      	<version>0.2.7-SNAPSHOT</version>
+      	<version>0.2.10-SNAPSHOT</version>
         <configuration>
           <hyracksServerHome>${basedir}/target/hadoopcompatserver-${project.version}-binary-assembly</hyracksServerHome>
           <jvmOptions>${jvm.extraargs}</jvmOptions>
@@ -149,27 +149,27 @@
      <dependency>
         <groupId>edu.uci.ics.hyracks.examples.compat</groupId>
         <artifactId>hadoopcompathelper</artifactId>
-        <version>0.2.7-SNAPSHOT</version>
+        <version>0.2.10-SNAPSHOT</version>
         <scope>compile</scope>
      </dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-control-cc</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-control-nc</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
      <dependency>
         <groupId>edu.uci.ics.hyracks.examples.compat</groupId>
   	    <artifactId>hadoopcompatclient</artifactId>
-  	    <version>0.2.7-SNAPSHOT</version>
+  	    <version>0.2.10-SNAPSHOT</version>
   	    <type>jar</type>
   	    <scope>test</scope>
      </dependency>
diff --git a/hyracks/hyracks-examples/hadoop-compat-example/pom.xml b/hyracks/hyracks-examples/hadoop-compat-example/pom.xml
index af88b09..5588134 100644
--- a/hyracks/hyracks-examples/hadoop-compat-example/pom.xml
+++ b/hyracks/hyracks-examples/hadoop-compat-example/pom.xml
@@ -22,7 +22,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks-examples</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <modules>
@@ -43,7 +43,7 @@
       <dependency>
          <groupId>edu.uci.ics.hyracks</groupId>
          <artifactId>hyracks-hadoop-compat</artifactId>
-         <version>0.2.7-SNAPSHOT</version>
+         <version>0.2.10-SNAPSHOT</version>
          <type>jar</type>
          <scope>compile</scope>
       </dependency>
diff --git a/hyracks/hyracks-examples/hyracks-integration-tests/pom.xml b/hyracks/hyracks-examples/hyracks-integration-tests/pom.xml
index a4fcf28..4893be4 100644
--- a/hyracks/hyracks-examples/hyracks-integration-tests/pom.xml
+++ b/hyracks/hyracks-examples/hyracks-integration-tests/pom.xml
@@ -20,7 +20,7 @@
 	<parent>
 		<groupId>edu.uci.ics.hyracks</groupId>
 		<artifactId>hyracks-examples</artifactId>
-		<version>0.2.7-SNAPSHOT</version>
+		<version>0.2.10-SNAPSHOT</version>
 	</parent>
 	<build>
 		<plugins>
@@ -46,75 +46,75 @@
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-dataflow-std</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-control-cc</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-control-nc</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-storage-am-btree</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-storage-am-rtree</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-storage-am-lsm-btree</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-storage-am-lsm-rtree</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-storage-am-lsm-invertedindex</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-test-support</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>test</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-data-std</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 		</dependency>
   	    <dependency>
             <groupId>edu.uci.ics.hyracks</groupId>
             <artifactId>hyracks-client</artifactId>
-            <version>0.2.7-SNAPSHOT</version>
+            <version>0.2.10-SNAPSHOT</version>
             <type>jar</type>
             <scope>compile</scope>
         </dependency>
diff --git a/hyracks/hyracks-examples/pom.xml b/hyracks/hyracks-examples/pom.xml
index 6296f5e..08f4a90 100644
--- a/hyracks/hyracks-examples/pom.xml
+++ b/hyracks/hyracks-examples/pom.xml
@@ -21,7 +21,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <modules>
diff --git a/hyracks/hyracks-examples/text-example/pom.xml b/hyracks/hyracks-examples/text-example/pom.xml
index 2359f96..ed9924a 100644
--- a/hyracks/hyracks-examples/text-example/pom.xml
+++ b/hyracks/hyracks-examples/text-example/pom.xml
@@ -21,7 +21,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks-examples</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <modules>
diff --git a/hyracks/hyracks-examples/text-example/textclient/pom.xml b/hyracks/hyracks-examples/text-example/textclient/pom.xml
index 0cd3d6c..6923241 100644
--- a/hyracks/hyracks-examples/text-example/textclient/pom.xml
+++ b/hyracks/hyracks-examples/text-example/textclient/pom.xml
@@ -20,20 +20,20 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>text-example</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <dependencies>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-dataflow-std</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>texthelper</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
diff --git a/hyracks/hyracks-examples/text-example/texthelper/pom.xml b/hyracks/hyracks-examples/text-example/texthelper/pom.xml
index e02138f..0c708a1 100644
--- a/hyracks/hyracks-examples/text-example/texthelper/pom.xml
+++ b/hyracks/hyracks-examples/text-example/texthelper/pom.xml
@@ -20,26 +20,26 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>text-example</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <dependencies>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-dataflow-std</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-api</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-data-std</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   	</dependency>
   </dependencies>
   <build>
diff --git a/hyracks/hyracks-examples/text-example/textserver/pom.xml b/hyracks/hyracks-examples/text-example/textserver/pom.xml
index aad72bd..b12f823 100644
--- a/hyracks/hyracks-examples/text-example/textserver/pom.xml
+++ b/hyracks/hyracks-examples/text-example/textserver/pom.xml
@@ -21,7 +21,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>text-example</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -73,7 +73,7 @@
       <plugin>
       	<groupId>edu.uci.ics.hyracks</groupId>
       	<artifactId>hyracks-virtualcluster-maven-plugin</artifactId>
-      	<version>0.2.7-SNAPSHOT</version>
+      	<version>0.2.10-SNAPSHOT</version>
         <configuration>
           <hyracksServerHome>${basedir}/target/textserver-${project.version}-binary-assembly</hyracksServerHome>
           <jvmOptions>${jvm.extraargs}</jvmOptions>
@@ -148,27 +148,27 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>texthelper</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-control-cc</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-control-nc</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>textclient</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>test</scope>
   	</dependency>
diff --git a/hyracks/hyracks-examples/tpch-example/pom.xml b/hyracks/hyracks-examples/tpch-example/pom.xml
index 129e38f..1b5f2b5 100644
--- a/hyracks/hyracks-examples/tpch-example/pom.xml
+++ b/hyracks/hyracks-examples/tpch-example/pom.xml
@@ -21,7 +21,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks-examples</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <modules>
diff --git a/hyracks/hyracks-examples/tpch-example/tpchclient/pom.xml b/hyracks/hyracks-examples/tpch-example/tpchclient/pom.xml
index 1123fe4..a872ecd 100644
--- a/hyracks/hyracks-examples/tpch-example/tpchclient/pom.xml
+++ b/hyracks/hyracks-examples/tpch-example/tpchclient/pom.xml
@@ -19,20 +19,20 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>tpch-example</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <dependencies>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-dataflow-std</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-data-std</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   	</dependency>
   </dependencies>
   <build>
diff --git a/hyracks/hyracks-examples/tpch-example/tpchserver/pom.xml b/hyracks/hyracks-examples/tpch-example/tpchserver/pom.xml
index d58f28c..712ba4c 100644
--- a/hyracks/hyracks-examples/tpch-example/tpchserver/pom.xml
+++ b/hyracks/hyracks-examples/tpch-example/tpchserver/pom.xml
@@ -21,7 +21,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>tpch-example</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -76,25 +76,25 @@
     <dependency>
         <groupId>edu.uci.ics.hyracks</groupId>
         <artifactId>hyracks-dataflow-std</artifactId>
-        <version>0.2.7-SNAPSHOT</version>
+        <version>0.2.10-SNAPSHOT</version>
         <scope>compile</scope>
     </dependency>
     <dependency>
     	<groupId>edu.uci.ics.hyracks</groupId>
     	<artifactId>hyracks-data-std</artifactId>
-    	<version>0.2.7-SNAPSHOT</version>
+    	<version>0.2.10-SNAPSHOT</version>
     </dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-control-cc</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-control-nc</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
diff --git a/hyracks/hyracks-hadoop-compat/pom.xml b/hyracks/hyracks-hadoop-compat/pom.xml
index 0a34b34..f6cfb71 100644
--- a/hyracks/hyracks-hadoop-compat/pom.xml
+++ b/hyracks/hyracks-hadoop-compat/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -94,7 +94,7 @@
     <dependency>
     	<groupId>edu.uci.ics.hyracks</groupId>
     	<artifactId>hyracks-dataflow-hadoop</artifactId>
-    	<version>0.2.7-SNAPSHOT</version>
+    	<version>0.2.10-SNAPSHOT</version>
     	<type>jar</type>
     	<scope>compile</scope>
     </dependency>
diff --git a/hyracks/hyracks-hdfs/hyracks-hdfs-0.20.2/pom.xml b/hyracks/hyracks-hdfs/hyracks-hdfs-0.20.2/pom.xml
index b7a8676..b93365d 100644
--- a/hyracks/hyracks-hdfs/hyracks-hdfs-0.20.2/pom.xml
+++ b/hyracks/hyracks-hdfs/hyracks-hdfs-0.20.2/pom.xml
@@ -20,7 +20,7 @@
 	<parent>
 		<artifactId>hyracks-hdfs</artifactId>
 		<groupId>edu.uci.ics.hyracks</groupId>
-		<version>0.2.7-SNAPSHOT</version>
+		<version>0.2.10-SNAPSHOT</version>
 	</parent>
 
 	<build>
@@ -112,7 +112,7 @@
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-api</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
diff --git a/hyracks/hyracks-hdfs/hyracks-hdfs-0.23.1/pom.xml b/hyracks/hyracks-hdfs/hyracks-hdfs-0.23.1/pom.xml
index 34400b6..7cd1091 100644
--- a/hyracks/hyracks-hdfs/hyracks-hdfs-0.23.1/pom.xml
+++ b/hyracks/hyracks-hdfs/hyracks-hdfs-0.23.1/pom.xml
@@ -20,7 +20,7 @@
 	<parent>
 		<artifactId>hyracks-hdfs</artifactId>
 		<groupId>edu.uci.ics.hyracks</groupId>
-		<version>0.2.7-SNAPSHOT</version>
+		<version>0.2.10-SNAPSHOT</version>
 	</parent>
 	<build>
 		<plugins>
@@ -216,7 +216,7 @@
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-api</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
diff --git a/hyracks/hyracks-hdfs/hyracks-hdfs-core/pom.xml b/hyracks/hyracks-hdfs/hyracks-hdfs-core/pom.xml
index b8453dd..b51d41d 100644
--- a/hyracks/hyracks-hdfs/hyracks-hdfs-core/pom.xml
+++ b/hyracks/hyracks-hdfs/hyracks-hdfs-core/pom.xml
@@ -1,26 +1,22 @@
 <?xml version="1.0"?>
-<!--
- ! Copyright 2009-2013 by The Regents of the University of California
- ! Licensed under the Apache License, Version 2.0 (the "License");
- ! you may not use this file except in compliance with the License.
- ! you may obtain a copy of the License from
- ! 
- !     http://www.apache.org/licenses/LICENSE-2.0
- ! 
- ! Unless required by applicable law or agreed to in writing, software
- ! distributed under the License is distributed on an "AS IS" BASIS,
- ! WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- ! See the License for the specific language governing permissions and
- ! limitations under the License.
- !-->
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<!-- ! Copyright 2009-2013 by The Regents of the University of California 
+	! Licensed under the Apache License, Version 2.0 (the "License"); ! you may 
+	not use this file except in compliance with the License. ! you may obtain 
+	a copy of the License from ! ! http://www.apache.org/licenses/LICENSE-2.0 
+	! ! Unless required by applicable law or agreed to in writing, software ! 
+	distributed under the License is distributed on an "AS IS" BASIS, ! WITHOUT 
+	WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. ! See the 
+	License for the specific language governing permissions and ! limitations 
+	under the License. ! -->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<artifactId>hyracks-hdfs-core</artifactId>
 	<name>hyracks-hdfs-core</name>
 	<parent>
 		<artifactId>hyracks-hdfs</artifactId>
 		<groupId>edu.uci.ics.hyracks</groupId>
-		<version>0.2.7-SNAPSHOT</version>
+		<version>0.2.10-SNAPSHOT</version>
 	</parent>
 
 	<build>
@@ -66,6 +62,18 @@
 					</filesets>
 				</configuration>
 			</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-jar-plugin</artifactId>
+				<version>2.2</version>
+				<executions>
+					<execution>
+						<goals>
+							<goal>test-jar</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
 		</plugins>
 	</build>
 
@@ -192,31 +200,31 @@
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-api</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-dataflow-std</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-dataflow-common</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-control-cc</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<scope>test</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-control-nc</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<scope>test</scope>
 		</dependency>
 		<dependency>
diff --git a/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/api/IKeyValueParser.java b/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/api/IKeyValueParser.java
index 1852a6f..57c20e0 100644
--- a/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/api/IKeyValueParser.java
+++ b/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/api/IKeyValueParser.java
@@ -38,18 +38,13 @@
     public void open(IFrameWriter writer) throws HyracksDataException;
 
     /**
-     * Parse a key-value pair returned by HDFS record reader to a tuple.
-     * when the parsers' internal buffer is full, it can flush the buffer to the writer
-     * 
      * @param key
-     *            The key returned from Hadoop's InputReader.
      * @param value
-     *            The value returned from Hadoop's InputReader.
      * @param writer
-     *            The hyracks writer for outputting data.
+     * @param fileName
      * @throws HyracksDataException
      */
-    public void parse(K key, V value, IFrameWriter writer) throws HyracksDataException;
+    public void parse(K key, V value, IFrameWriter writer, String fileString) throws HyracksDataException;
 
     /**
      * Flush the residual tuples in the internal buffer to the writer.
diff --git a/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/api/ITupleWriterFactory.java b/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/api/ITupleWriterFactory.java
index 674873d..7e6e4dc 100644
--- a/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/api/ITupleWriterFactory.java
+++ b/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/api/ITupleWriterFactory.java
@@ -30,6 +30,6 @@
      *            the IHyracksTaskContext
      * @return a tuple writer instance
      */
-    public ITupleWriter getTupleWriter(IHyracksTaskContext ctx) throws HyracksDataException;
+    public ITupleWriter getTupleWriter(IHyracksTaskContext ctx, int partition, int nPartition) throws HyracksDataException;
 
 }
diff --git a/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/dataflow/HDFSReadOperatorDescriptor.java b/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/dataflow/HDFSReadOperatorDescriptor.java
index 2cff534..814be7a 100644
--- a/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/dataflow/HDFSReadOperatorDescriptor.java
+++ b/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/dataflow/HDFSReadOperatorDescriptor.java
@@ -98,8 +98,9 @@
             public void initialize() throws HyracksDataException {
                 ClassLoader ctxCL = Thread.currentThread().getContextClassLoader();
                 try {
-                    Thread.currentThread().setContextClassLoader(getClass().getClassLoader());
+                    Thread.currentThread().setContextClassLoader(ctx.getJobletContext().getClassLoader());
                     JobConf conf = confFactory.getConf();
+                    conf.setClassLoader(ctx.getJobletContext().getClassLoader());
                     IKeyValueParser parser = tupleParserFactory.createKeyValueParser(ctx);
                     writer.open();
                     parser.open(writer);
@@ -128,7 +129,7 @@
                             Object key = reader.createKey();
                             Object value = reader.createValue();
                             while (reader.next(key, value) == true) {
-                                parser.parse(key, value, writer);
+                                parser.parse(key, value, writer, inputSplits[i].toString());
                             }
                         }
                     }
diff --git a/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/dataflow/HDFSWriteOperatorDescriptor.java b/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/dataflow/HDFSWriteOperatorDescriptor.java
index 432849b..4e48e9b 100644
--- a/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/dataflow/HDFSWriteOperatorDescriptor.java
+++ b/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/dataflow/HDFSWriteOperatorDescriptor.java
@@ -89,7 +89,7 @@
                 String outputDirPath = FileOutputFormat.getOutputPath(conf).toString();
                 String fileName = outputDirPath + File.separator + "part-" + partition;
 
-                tupleWriter = tupleWriterFactory.getTupleWriter(ctx);
+                tupleWriter = tupleWriterFactory.getTupleWriter(ctx, partition, nPartitions);
                 try {
                     FileSystem dfs = FileSystem.get(conf);
                     dos = dfs.create(new Path(fileName), true);
diff --git a/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/lib/TextKeyValueParserFactory.java b/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/lib/TextKeyValueParserFactory.java
index fbac95b..92cde9d 100644
--- a/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/lib/TextKeyValueParserFactory.java
+++ b/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/lib/TextKeyValueParserFactory.java
@@ -49,7 +49,8 @@
             }
 
             @Override
-            public void parse(LongWritable key, Text value, IFrameWriter writer) throws HyracksDataException {
+            public void parse(LongWritable key, Text value, IFrameWriter writer, String fileString)
+                    throws HyracksDataException {
                 tb.reset();
                 tb.addField(value.getBytes(), 0, value.getLength());
                 if (!appender.append(tb.getFieldEndOffsets(), tb.getByteArray(), 0, tb.getSize())) {
diff --git a/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/lib/TextTupleWriterFactory.java b/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/lib/TextTupleWriterFactory.java
index 92a427e..60be1f7 100644
--- a/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/lib/TextTupleWriterFactory.java
+++ b/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs/lib/TextTupleWriterFactory.java
@@ -27,7 +27,7 @@
     private static final long serialVersionUID = 1L;
 
     @Override
-    public ITupleWriter getTupleWriter(IHyracksTaskContext ctx) {
+    public ITupleWriter getTupleWriter(IHyracksTaskContext ctx, int partition, int nPartition) {
         return new ITupleWriter() {
             private byte newLine = "\n".getBytes()[0];
 
diff --git a/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs2/dataflow/HDFSReadOperatorDescriptor.java b/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs2/dataflow/HDFSReadOperatorDescriptor.java
index 3f01d77..bc47360 100644
--- a/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs2/dataflow/HDFSReadOperatorDescriptor.java
+++ b/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs2/dataflow/HDFSReadOperatorDescriptor.java
@@ -112,7 +112,7 @@
             public void initialize() throws HyracksDataException {
                 ClassLoader ctxCL = Thread.currentThread().getContextClassLoader();
                 try {
-                    Thread.currentThread().setContextClassLoader(this.getClass().getClassLoader());
+                    Thread.currentThread().setContextClassLoader(ctx.getJobletContext().getClassLoader());
                     Job job = confFactory.getConf();
                     job.getConfiguration().setClassLoader(ctx.getJobletContext().getClassLoader());
                     IKeyValueParser parser = tupleParserFactory.createKeyValueParser(ctx);
@@ -141,10 +141,12 @@
                              * read the split
                              */
                             TaskAttemptContext context = ctxFactory.createContext(job.getConfiguration(), i);
+                            context.getConfiguration().setClassLoader(ctx.getJobletContext().getClassLoader());
                             RecordReader reader = inputFormat.createRecordReader(inputSplits.get(i), context);
                             reader.initialize(inputSplits.get(i), context);
                             while (reader.nextKeyValue() == true) {
-                                parser.parse(reader.getCurrentKey(), reader.getCurrentValue(), writer);
+                                parser.parse(reader.getCurrentKey(), reader.getCurrentValue(), writer,
+                                        inputSplits.get(i).toString());
                             }
                         }
                     }
diff --git a/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs2/dataflow/HDFSWriteOperatorDescriptor.java b/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs2/dataflow/HDFSWriteOperatorDescriptor.java
index 77b8c7e..068cdfc 100644
--- a/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs2/dataflow/HDFSWriteOperatorDescriptor.java
+++ b/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs2/dataflow/HDFSWriteOperatorDescriptor.java
@@ -88,7 +88,7 @@
                 String outputPath = FileOutputFormat.getOutputPath(conf).toString();
                 String fileName = outputPath + File.separator + "part-" + partition;
 
-                tupleWriter = tupleWriterFactory.getTupleWriter(ctx);
+                tupleWriter = tupleWriterFactory.getTupleWriter(ctx, partition, nPartitions);
                 try {
                     FileSystem dfs = FileSystem.get(conf.getConfiguration());
                     dos = dfs.create(new Path(fileName), true);
diff --git a/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs2/scheduler/Scheduler.java b/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs2/scheduler/Scheduler.java
index 75553e1..85f80ac 100644
--- a/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs2/scheduler/Scheduler.java
+++ b/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/edu/uci/ics/hyracks/hdfs2/scheduler/Scheduler.java
@@ -23,6 +23,7 @@
 import edu.uci.ics.hyracks.api.client.NodeControllerInfo;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
+import edu.uci.ics.hyracks.api.topology.ClusterTopology;
 import edu.uci.ics.hyracks.hdfs.api.INcCollectionBuilder;
 
 /**
@@ -54,7 +55,20 @@
     public Scheduler(Map<String, NodeControllerInfo> ncNameToNcInfos) throws HyracksException {
         scheduler = new edu.uci.ics.hyracks.hdfs.scheduler.Scheduler(ncNameToNcInfos);
     }
-    
+
+    /**
+     * The constructor of the scheduler.
+     * 
+     * @param ncNameToNcInfos
+     *            the mapping from nc names to nc infos
+     * @param topology
+     *            the hyracks cluster toplogy
+     * @throws HyracksException
+     */
+    public Scheduler(Map<String, NodeControllerInfo> ncNameToNcInfos, ClusterTopology topology) throws HyracksException {
+        scheduler = new edu.uci.ics.hyracks.hdfs.scheduler.Scheduler(ncNameToNcInfos, topology);
+    }
+
     /**
      * The constructor of the scheduler.
      * 
@@ -62,7 +76,8 @@
      *            the mapping from nc names to nc infos
      * @throws HyracksException
      */
-    public Scheduler(Map<String, NodeControllerInfo> ncNameToNcInfos, INcCollectionBuilder builder) throws HyracksException {
+    public Scheduler(Map<String, NodeControllerInfo> ncNameToNcInfos, INcCollectionBuilder builder)
+            throws HyracksException {
         scheduler = new edu.uci.ics.hyracks.hdfs.scheduler.Scheduler(ncNameToNcInfos, builder);
     }
 
diff --git a/hyracks/hyracks-hdfs/pom.xml b/hyracks/hyracks-hdfs/pom.xml
index 0035285..b174d37 100644
--- a/hyracks/hyracks-hdfs/pom.xml
+++ b/hyracks/hyracks-hdfs/pom.xml
@@ -22,7 +22,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <modules>
diff --git a/hyracks/hyracks-ipc/pom.xml b/hyracks/hyracks-ipc/pom.xml
index 88bb49c..fed59e6 100644
--- a/hyracks/hyracks-ipc/pom.xml
+++ b/hyracks/hyracks-ipc/pom.xml
@@ -19,7 +19,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
diff --git a/hyracks/hyracks-ipc/src/main/java/edu/uci/ics/hyracks/ipc/impl/IPCConnectionManager.java b/hyracks/hyracks-ipc/src/main/java/edu/uci/ics/hyracks/ipc/impl/IPCConnectionManager.java
index c52dbd8..81294c2 100644
--- a/hyracks/hyracks-ipc/src/main/java/edu/uci/ics/hyracks/ipc/impl/IPCConnectionManager.java
+++ b/hyracks/hyracks-ipc/src/main/java/edu/uci/ics/hyracks/ipc/impl/IPCConnectionManager.java
@@ -17,6 +17,7 @@
 import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.net.ServerSocket;
+import java.net.StandardSocketOptions;
 import java.nio.ByteBuffer;
 import java.nio.channels.ClosedChannelException;
 import java.nio.channels.SelectableChannel;
@@ -175,6 +176,7 @@
                     if (!workingPendingConnections.isEmpty()) {
                         for (IPCHandle handle : workingPendingConnections) {
                             SocketChannel channel = SocketChannel.open();
+                            channel.setOption(StandardSocketOptions.TCP_NODELAY, true);
                             channel.configureBlocking(false);
                             SelectionKey cKey = null;
                             if (channel.connect(handle.getRemoteAddress())) {
@@ -267,6 +269,7 @@
                             } else if (key.isAcceptable()) {
                                 assert sc == serverSocketChannel;
                                 SocketChannel channel = serverSocketChannel.accept();
+                                channel.setOption(StandardSocketOptions.TCP_NODELAY, true);
                                 channel.configureBlocking(false);
                                 IPCHandle handle = new IPCHandle(system, null);
                                 SelectionKey cKey = channel.register(selector, SelectionKey.OP_READ);
diff --git a/hyracks/hyracks-maven-plugins/hyracks-virtualcluster-maven-plugin/pom.xml b/hyracks/hyracks-maven-plugins/hyracks-virtualcluster-maven-plugin/pom.xml
index df11910..5ffbf28 100644
--- a/hyracks/hyracks-maven-plugins/hyracks-virtualcluster-maven-plugin/pom.xml
+++ b/hyracks/hyracks-maven-plugins/hyracks-virtualcluster-maven-plugin/pom.xml
@@ -21,7 +21,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks-maven-plugins</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
diff --git a/hyracks/hyracks-maven-plugins/pom.xml b/hyracks/hyracks-maven-plugins/pom.xml
index 6d8a2ec..a2b8d03 100644
--- a/hyracks/hyracks-maven-plugins/pom.xml
+++ b/hyracks/hyracks-maven-plugins/pom.xml
@@ -21,7 +21,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <dependencies>
diff --git a/hyracks/hyracks-net/pom.xml b/hyracks/hyracks-net/pom.xml
index e5853b7..a188f4c 100644
--- a/hyracks/hyracks-net/pom.xml
+++ b/hyracks/hyracks-net/pom.xml
@@ -19,7 +19,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
diff --git a/hyracks/hyracks-net/src/main/java/edu/uci/ics/hyracks/net/protocols/tcp/TCPEndpoint.java b/hyracks/hyracks-net/src/main/java/edu/uci/ics/hyracks/net/protocols/tcp/TCPEndpoint.java
index 932d71a..067898f 100644
--- a/hyracks/hyracks-net/src/main/java/edu/uci/ics/hyracks/net/protocols/tcp/TCPEndpoint.java
+++ b/hyracks/hyracks-net/src/main/java/edu/uci/ics/hyracks/net/protocols/tcp/TCPEndpoint.java
@@ -17,6 +17,7 @@
 import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.net.ServerSocket;
+import java.net.StandardSocketOptions;
 import java.nio.channels.SelectableChannel;
 import java.nio.channels.SelectionKey;
 import java.nio.channels.Selector;
@@ -118,6 +119,7 @@
                     if (!workingPendingConnections.isEmpty()) {
                         for (InetSocketAddress address : workingPendingConnections) {
                             SocketChannel channel = SocketChannel.open();
+                            channel.setOption(StandardSocketOptions.TCP_NODELAY, true);
                             channel.configureBlocking(false);
                             boolean connect = false;
                             boolean failure = false;
@@ -143,6 +145,7 @@
                     }
                     if (!workingIncomingConnections.isEmpty()) {
                         for (SocketChannel channel : workingIncomingConnections) {
+                            channel.setOption(StandardSocketOptions.TCP_NODELAY, true);
                             channel.configureBlocking(false);
                             SelectionKey sKey = channel.register(selector, 0);
                             TCPConnection connection = new TCPConnection(TCPEndpoint.this, channel, sKey, selector);
diff --git a/hyracks/hyracks-server/pom.xml b/hyracks/hyracks-server/pom.xml
index 646880d..f691481 100644
--- a/hyracks/hyracks-server/pom.xml
+++ b/hyracks/hyracks-server/pom.xml
@@ -19,7 +19,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -88,14 +88,14 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-control-cc</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-control-nc</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
diff --git a/hyracks/hyracks-storage-am-bloomfilter/pom.xml b/hyracks/hyracks-storage-am-bloomfilter/pom.xml
index 7d9a92e..a712ab4 100644
--- a/hyracks/hyracks-storage-am-bloomfilter/pom.xml
+++ b/hyracks/hyracks-storage-am-bloomfilter/pom.xml
@@ -19,7 +19,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -39,7 +39,7 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-common</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>  	
diff --git a/hyracks/hyracks-storage-am-bloomfilter/src/main/java/edu/uci/ics/hyracks/storage/am/bloomfilter/impls/BloomFilter.java b/hyracks/hyracks-storage-am-bloomfilter/src/main/java/edu/uci/ics/hyracks/storage/am/bloomfilter/impls/BloomFilter.java
index 6811e1b..fe25db8 100644
--- a/hyracks/hyracks-storage-am-bloomfilter/src/main/java/edu/uci/ics/hyracks/storage/am/bloomfilter/impls/BloomFilter.java
+++ b/hyracks/hyracks-storage-am-bloomfilter/src/main/java/edu/uci/ics/hyracks/storage/am/bloomfilter/impls/BloomFilter.java
@@ -47,7 +47,8 @@
     private int numHashes;
     private long numElements;
     private long numBits;
-    private int numBitsPerPage;
+    private final int numBitsPerPage;
+    private final static byte[] ZERO_BUFFER = new byte[131072]; // 128kb
 
     private final ArrayList<ICachedPage> bloomFilterPages = new ArrayList<ICachedPage>();
     private final static long SEED = 0L;
@@ -58,7 +59,7 @@
         this.fileMapProvider = fileMapProvider;
         this.file = file;
         this.keyFields = keyFields;
-        numBitsPerPage = bufferCache.getPageSize() * Byte.SIZE;
+        this.numBitsPerPage = bufferCache.getPageSize() * Byte.SIZE;
     }
 
     public int getFileId() {
@@ -198,7 +199,6 @@
 
     public class BloomFilterBuilder implements IIndexBulkLoader {
         private final long[] hashes = new long[2];
-
         private final long numElements;
         private final int numHashes;
         private final long numBits;
@@ -217,16 +217,28 @@
                 throw new HyracksDataException("Cannot create a bloom filter with his huge number of pages.");
             }
             numPages = (int) tmp;
-            if (this.numElements > 0) {
-                persistBloomFilterMetaData();
-                readBloomFilterMetaData();
-                int currentPageId = 1;
-                while (currentPageId <= numPages) {
-                    ICachedPage page = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, currentPageId), true);
-                    page.acquireWriteLatch();
-                    bloomFilterPages.add(page);
-                    ++currentPageId;
-                }
+            persistBloomFilterMetaData();
+            readBloomFilterMetaData();
+            int currentPageId = 1;
+            while (currentPageId <= numPages) {
+                ICachedPage page = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, currentPageId), true);
+                page.acquireWriteLatch();
+                initPage(page.getBuffer().array());
+                bloomFilterPages.add(page);
+                ++currentPageId;
+            }
+        }
+
+        private void initPage(byte[] array) {
+            int numRounds = array.length / ZERO_BUFFER.length;
+            int leftOver = array.length % ZERO_BUFFER.length;
+            int destPos = 0;
+            for (int i = 0; i < numRounds; i++) {
+                System.arraycopy(ZERO_BUFFER, 0, array, destPos, ZERO_BUFFER.length);
+                destPos = (i + 1) * ZERO_BUFFER.length;
+            }
+            if (leftOver > 0) {
+                System.arraycopy(ZERO_BUFFER, 0, array, destPos, leftOver);
             }
         }
 
diff --git a/hyracks/hyracks-storage-am-bloomfilter/src/main/java/edu/uci/ics/hyracks/storage/am/bloomfilter/impls/BloomFilterSpecification.java b/hyracks/hyracks-storage-am-bloomfilter/src/main/java/edu/uci/ics/hyracks/storage/am/bloomfilter/impls/BloomFilterSpecification.java
index a1e5517..0c5d7c8 100644
--- a/hyracks/hyracks-storage-am-bloomfilter/src/main/java/edu/uci/ics/hyracks/storage/am/bloomfilter/impls/BloomFilterSpecification.java
+++ b/hyracks/hyracks-storage-am-bloomfilter/src/main/java/edu/uci/ics/hyracks/storage/am/bloomfilter/impls/BloomFilterSpecification.java
@@ -16,12 +16,12 @@
 package edu.uci.ics.hyracks.storage.am.bloomfilter.impls;
 
 public final class BloomFilterSpecification {
-    private final int numBucketsPerElement;
     private final int numHashes;
+    private final int numBucketsPerElement;
 
-    public BloomFilterSpecification(int numBucketsPerElement, int numHashes) {
-        this.numBucketsPerElement = numBucketsPerElement;
+    public BloomFilterSpecification(int numHashes, int numBucketsPerElement) {
         this.numHashes = numHashes;
+        this.numBucketsPerElement = numBucketsPerElement;
     }
 
     public int getNumBucketsPerElements() {
@@ -31,4 +31,4 @@
     public int getNumHashes() {
         return numHashes;
     }
-}
+}
\ No newline at end of file
diff --git a/hyracks/hyracks-storage-am-btree/pom.xml b/hyracks/hyracks-storage-am-btree/pom.xml
index 4878a44..2746666 100644
--- a/hyracks/hyracks-storage-am-btree/pom.xml
+++ b/hyracks/hyracks-storage-am-btree/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -41,28 +41,28 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-common</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>  	
         <dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-common</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>  	
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-dataflow-common</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>  	
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-dataflow-std</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>  	
diff --git a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeNonExistentKeyException.java b/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeNonExistentKeyException.java
deleted file mode 100644
index 7237046..0000000
--- a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeNonExistentKeyException.java
+++ /dev/null
@@ -1,29 +0,0 @@
-/*
- * Copyright 2009-2013 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package edu.uci.ics.hyracks.storage.am.btree.exceptions;
-
-public class BTreeNonExistentKeyException extends BTreeException {
-
-    private static final long serialVersionUID = 1L;
-
-    public BTreeNonExistentKeyException(Exception e) {
-        super(e);
-    }
-
-    public BTreeNonExistentKeyException(String message) {
-        super(message);
-    }
-}
diff --git a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeFieldPrefixNSMLeafFrame.java b/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeFieldPrefixNSMLeafFrame.java
index b503c8b..93cde3d 100644
--- a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeFieldPrefixNSMLeafFrame.java
+++ b/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeFieldPrefixNSMLeafFrame.java
@@ -25,8 +25,6 @@
 import edu.uci.ics.hyracks.storage.am.btree.api.IBTreeLeafFrame;
 import edu.uci.ics.hyracks.storage.am.btree.api.IPrefixSlotManager;
 import edu.uci.ics.hyracks.storage.am.btree.compressors.FieldPrefixCompressor;
-import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeDuplicateKeyException;
-import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeNonExistentKeyException;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTreeOpContext.PageValidationInfo;
 import edu.uci.ics.hyracks.storage.am.btree.impls.FieldPrefixPrefixTupleReference;
 import edu.uci.ics.hyracks.storage.am.btree.impls.FieldPrefixSlotManager;
@@ -37,6 +35,8 @@
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexTupleReference;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexTupleWriter;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
+import edu.uci.ics.hyracks.storage.am.common.exceptions.TreeIndexDuplicateKeyException;
+import edu.uci.ics.hyracks.storage.am.common.exceptions.TreeIndexNonExistentKeyException;
 import edu.uci.ics.hyracks.storage.am.common.frames.FrameOpSpaceStatus;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.FindTupleMode;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.FindTupleNoExactMatchPolicy;
@@ -370,7 +370,7 @@
         int tupleIndex = slotManager.decodeSecondSlotField(slot);
         // Error indicator is set if there is an exact match.
         if (tupleIndex == slotManager.getErrorIndicator()) {
-            throw new BTreeDuplicateKeyException("Trying to insert duplicate key into leaf node.");
+            throw new TreeIndexDuplicateKeyException("Trying to insert duplicate key into leaf node.");
         }
         return slot;
     }
@@ -382,7 +382,7 @@
         int tupleIndex = slotManager.decodeSecondSlotField(slot);
         // Error indicator is set if there is an exact match.
         if (tupleIndex == slotManager.getErrorIndicator()) {
-            throw new BTreeDuplicateKeyException("Trying to insert duplicate key into leaf node.");
+            throw new TreeIndexDuplicateKeyException("Trying to insert duplicate key into leaf node.");
         }
         return slot;
     }
@@ -411,7 +411,7 @@
         int tupleIndex = slotManager.decodeSecondSlotField(slot);
         // Error indicator is set if there is no exact match.
         if (tupleIndex == slotManager.getErrorIndicator()) {
-            throw new BTreeNonExistentKeyException("Trying to update a tuple with a nonexistent key in leaf node.");
+            throw new TreeIndexNonExistentKeyException("Trying to update a tuple with a nonexistent key in leaf node.");
         }
         return slot;
     }
@@ -423,7 +423,7 @@
         int tupleIndex = slotManager.decodeSecondSlotField(slot);
         // Error indicator is set if there is no exact match.
         if (tupleIndex == slotManager.getErrorIndicator()) {
-            throw new BTreeNonExistentKeyException("Trying to delete a tuple with a nonexistent key in leaf node.");
+            throw new TreeIndexNonExistentKeyException("Trying to delete a tuple with a nonexistent key in leaf node.");
         }
         return slot;
     }
diff --git a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeNSMLeafFrame.java b/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeNSMLeafFrame.java
index 1974989..187cd52 100644
--- a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeNSMLeafFrame.java
+++ b/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/frames/BTreeNSMLeafFrame.java
@@ -20,14 +20,14 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
 import edu.uci.ics.hyracks.storage.am.btree.api.IBTreeLeafFrame;
-import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeDuplicateKeyException;
-import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeNonExistentKeyException;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTreeOpContext.PageValidationInfo;
 import edu.uci.ics.hyracks.storage.am.common.api.ISplitKey;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrame;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexTupleReference;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexTupleWriter;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
+import edu.uci.ics.hyracks.storage.am.common.exceptions.TreeIndexDuplicateKeyException;
+import edu.uci.ics.hyracks.storage.am.common.exceptions.TreeIndexNonExistentKeyException;
 import edu.uci.ics.hyracks.storage.am.common.frames.TreeIndexNSMFrame;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.FindTupleMode;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.FindTupleNoExactMatchPolicy;
@@ -72,7 +72,7 @@
                 FindTupleNoExactMatchPolicy.HIGHER_KEY);
         // Error indicator is set if there is an exact match.
         if (tupleIndex == slotManager.getErrorIndicator()) {
-            throw new BTreeDuplicateKeyException("Trying to insert duplicate key into leaf node.");
+            throw new TreeIndexDuplicateKeyException("Trying to insert duplicate key into leaf node.");
         }
         return tupleIndex;
     }
@@ -83,7 +83,7 @@
                 FindTupleNoExactMatchPolicy.HIGHER_KEY);
         // Error indicator is set if there is no exact match.
         if (tupleIndex == slotManager.getErrorIndicator() || tupleIndex == slotManager.getGreatestKeyIndicator()) {
-            throw new BTreeNonExistentKeyException("Trying to update a tuple with a nonexistent key in leaf node.");
+            throw new TreeIndexNonExistentKeyException("Trying to update a tuple with a nonexistent key in leaf node.");
         }
         return tupleIndex;
     }
@@ -121,7 +121,7 @@
                 FindTupleNoExactMatchPolicy.HIGHER_KEY);
         // Error indicator is set if there is no exact match.
         if (tupleIndex == slotManager.getErrorIndicator() || tupleIndex == slotManager.getGreatestKeyIndicator()) {
-            throw new BTreeNonExistentKeyException("Trying to delete a tuple with a nonexistent key in leaf node.");
+            throw new TreeIndexNonExistentKeyException("Trying to delete a tuple with a nonexistent key in leaf node.");
         }
         return tupleIndex;
     }
diff --git a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTree.java b/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTree.java
index 689843b..ff94040 100644
--- a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTree.java
+++ b/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTree.java
@@ -33,7 +33,6 @@
 import edu.uci.ics.hyracks.storage.am.btree.api.IBTreeLeafFrame;
 import edu.uci.ics.hyracks.storage.am.btree.api.ITupleAcceptor;
 import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeException;
-import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeNonExistentKeyException;
 import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeNotUpdateableException;
 import edu.uci.ics.hyracks.storage.am.btree.frames.BTreeNSMInteriorFrame;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTreeOpContext.PageValidationInfo;
@@ -53,6 +52,8 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
 import edu.uci.ics.hyracks.storage.am.common.api.UnsortedInputException;
+import edu.uci.ics.hyracks.storage.am.common.exceptions.TreeIndexDuplicateKeyException;
+import edu.uci.ics.hyracks.storage.am.common.exceptions.TreeIndexNonExistentKeyException;
 import edu.uci.ics.hyracks.storage.am.common.frames.FrameOpSpaceStatus;
 import edu.uci.ics.hyracks.storage.am.common.impls.AbstractTreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
@@ -562,7 +563,7 @@
         // This means that there could be underflow, even an empty page that is
         // pointed to by an interior node.
         if (ctx.leafFrame.getTupleCount() == 0) {
-            throw new BTreeNonExistentKeyException("Trying to delete a tuple with a nonexistent key in leaf node.");
+            throw new TreeIndexNonExistentKeyException("Trying to delete a tuple with a nonexistent key in leaf node.");
         }
         int tupleIndex = ctx.leafFrame.findDeleteTupleIndex(tuple);
         ITupleReference beforeTuple = ctx.leafFrame.getMatchingKeyTuple(tuple, tupleIndex);
@@ -1024,9 +1025,12 @@
         protected void verifyInputTuple(ITupleReference tuple, ITupleReference prevTuple) throws IndexException,
                 HyracksDataException {
             // New tuple should be strictly greater than last tuple.
-            if (cmp.compare(tuple, prevTuple) <= 0) {
-                throw new UnsortedInputException(
-                        "Input stream given to BTree bulk load is not sorted or has duplicates.");
+            int cmpResult = cmp.compare(tuple, prevTuple);
+            if (cmpResult < 0) {
+                throw new UnsortedInputException("Input stream given to BTree bulk load is not sorted.");
+            }
+            if (cmpResult == 0) {
+                throw new TreeIndexDuplicateKeyException("Input stream given to BTree bulk load has duplicates.");
             }
         }
 
diff --git a/hyracks/hyracks-storage-am-common/pom.xml b/hyracks/hyracks-storage-am-common/pom.xml
index 33bbe5e..309f183 100644
--- a/hyracks/hyracks-storage-am-common/pom.xml
+++ b/hyracks/hyracks-storage-am-common/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -41,28 +41,28 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-api</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-common</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-dataflow-common</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-dataflow-std</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
diff --git a/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/IndexInsertUpdateDeleteOperatorNodePushable.java b/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/IndexInsertUpdateDeleteOperatorNodePushable.java
index 4a9cfb4..092fada 100644
--- a/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/IndexInsertUpdateDeleteOperatorNodePushable.java
+++ b/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/IndexInsertUpdateDeleteOperatorNodePushable.java
@@ -30,6 +30,8 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IModificationOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.api.ITupleFilter;
 import edu.uci.ics.hyracks.storage.am.common.api.ITupleFilterFactory;
+import edu.uci.ics.hyracks.storage.am.common.exceptions.TreeIndexDuplicateKeyException;
+import edu.uci.ics.hyracks.storage.am.common.exceptions.TreeIndexNonExistentKeyException;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
 import edu.uci.ics.hyracks.storage.am.common.tuples.PermutingFrameTupleReference;
@@ -97,7 +99,11 @@
 
                 switch (op) {
                     case INSERT: {
-                        indexAccessor.insert(tuple);
+                        try {
+                            indexAccessor.insert(tuple);
+                        } catch (TreeIndexDuplicateKeyException e) {
+                            // ingnore that exception to allow inserting existing keys which becomes an NoOp
+                        }
                         break;
                     }
                     case UPDATE: {
@@ -109,7 +115,11 @@
                         break;
                     }
                     case DELETE: {
-                        indexAccessor.delete(tuple);
+                        try {
+                            indexAccessor.delete(tuple);
+                        } catch (TreeIndexNonExistentKeyException e) {
+                            // ingnore that exception to allow deletions of non-existing keys
+                        }
                         break;
                     }
                     default: {
diff --git a/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/IndexSearchOperatorNodePushable.java b/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/IndexSearchOperatorNodePushable.java
index a79daef..83fb5ee 100644
--- a/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/IndexSearchOperatorNodePushable.java
+++ b/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/IndexSearchOperatorNodePushable.java
@@ -119,7 +119,8 @@
                 FrameUtils.flushFrame(writeBuffer, writer);
                 appender.reset(writeBuffer, true);
                 if (!appender.append(tb.getFieldEndOffsets(), tb.getByteArray(), 0, tb.getSize())) {
-                    throw new HyracksDataException("Record size (" + tb.getSize() + ") larger than frame size (" + appender.getBuffer().capacity() + ")");
+                    throw new HyracksDataException("Record size (" + tb.getSize() + ") larger than frame size ("
+                            + appender.getBuffer().capacity() + ")");
                 }
             }
         }
diff --git a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java b/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/exceptions/TreeIndexDuplicateKeyException.java
similarity index 70%
rename from hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
rename to hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/exceptions/TreeIndexDuplicateKeyException.java
index cde5022..1767504 100644
--- a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
+++ b/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/exceptions/TreeIndexDuplicateKeyException.java
@@ -13,16 +13,18 @@
  * limitations under the License.
  */
 
-package edu.uci.ics.hyracks.storage.am.btree.exceptions;
+package edu.uci.ics.hyracks.storage.am.common.exceptions;
 
-public class BTreeDuplicateKeyException extends BTreeException {
+import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
+
+public class TreeIndexDuplicateKeyException extends TreeIndexException {
     private static final long serialVersionUID = 1L;
 
-    public BTreeDuplicateKeyException(Exception e) {
+    public TreeIndexDuplicateKeyException(Exception e) {
         super(e);
     }
 
-    public BTreeDuplicateKeyException(String message) {
+    public TreeIndexDuplicateKeyException(String message) {
         super(message);
     }
 }
diff --git a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java b/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/exceptions/TreeIndexNonExistentKeyException.java
similarity index 61%
copy from hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
copy to hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/exceptions/TreeIndexNonExistentKeyException.java
index cde5022..8b62063 100644
--- a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
+++ b/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/exceptions/TreeIndexNonExistentKeyException.java
@@ -13,16 +13,19 @@
  * limitations under the License.
  */
 
-package edu.uci.ics.hyracks.storage.am.btree.exceptions;
+package edu.uci.ics.hyracks.storage.am.common.exceptions;
 
-public class BTreeDuplicateKeyException extends BTreeException {
-    private static final long serialVersionUID = 1L;
+import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
 
-    public BTreeDuplicateKeyException(Exception e) {
-        super(e);
-    }
+public class TreeIndexNonExistentKeyException extends TreeIndexException {
 
-    public BTreeDuplicateKeyException(String message) {
-        super(message);
-    }
+	private static final long serialVersionUID = 1L;
+
+	public TreeIndexNonExistentKeyException(Exception e) {
+		super(e);
+	}
+
+	public TreeIndexNonExistentKeyException(String message) {
+		super(message);
+	}
 }
diff --git a/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/impls/AbstractTreeIndex.java b/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/impls/AbstractTreeIndex.java
index 19d40a0..c14f23a 100644
--- a/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/impls/AbstractTreeIndex.java
+++ b/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/impls/AbstractTreeIndex.java
@@ -12,352 +12,360 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-
-package edu.uci.ics.hyracks.storage.am.common.impls;
-
-import java.util.ArrayList;
-
-import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.api.io.FileReference;
-import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
-import edu.uci.ics.hyracks.storage.am.common.api.IFreePageManager;
-import edu.uci.ics.hyracks.storage.am.common.api.IIndexBulkLoader;
-import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
-import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexAccessor;
-import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrame;
-import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrameFactory;
-import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrame;
-import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexTupleWriter;
-import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
-import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
-import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
-import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
-import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPage;
-import edu.uci.ics.hyracks.storage.common.file.BufferedFileHandle;
-import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
-
-public abstract class AbstractTreeIndex implements ITreeIndex {
-
-    protected final static int rootPage = 1;
-
-    protected final IBufferCache bufferCache;
-    protected final IFileMapProvider fileMapProvider;
-    protected final IFreePageManager freePageManager;
-
-    protected final ITreeIndexFrameFactory interiorFrameFactory;
-    protected final ITreeIndexFrameFactory leafFrameFactory;
-
-    protected final IBinaryComparatorFactory[] cmpFactories;
-    protected final int fieldCount;
-
-    protected FileReference file;
-    protected int fileId = -1;
-
-    private boolean isActivated = false;
-
-    public AbstractTreeIndex(IBufferCache bufferCache, IFileMapProvider fileMapProvider,
-            IFreePageManager freePageManager, ITreeIndexFrameFactory interiorFrameFactory,
-            ITreeIndexFrameFactory leafFrameFactory, IBinaryComparatorFactory[] cmpFactories, int fieldCount,
-            FileReference file) {
-        this.bufferCache = bufferCache;
-        this.fileMapProvider = fileMapProvider;
-        this.freePageManager = freePageManager;
-        this.interiorFrameFactory = interiorFrameFactory;
-        this.leafFrameFactory = leafFrameFactory;
-        this.cmpFactories = cmpFactories;
-        this.fieldCount = fieldCount;
-        this.file = file;
-    }
-
-    public synchronized void create() throws HyracksDataException {
-        if (isActivated) {
-            throw new HyracksDataException("Failed to create the index since it is activated.");
-        }
-
-        boolean fileIsMapped = false;
-        synchronized (fileMapProvider) {
-            fileIsMapped = fileMapProvider.isMapped(file);
-            if (!fileIsMapped) {
-                bufferCache.createFile(file);
-            }
-            fileId = fileMapProvider.lookupFileId(file);
-            try {
-                // Also creates the file if it doesn't exist yet.
-                bufferCache.openFile(fileId);
-            } catch (HyracksDataException e) {
-                // Revert state of buffer cache since file failed to open.
-                if (!fileIsMapped) {
-                    bufferCache.deleteFile(fileId, false);
-                }
-                throw e;
-            }
-        }
-
-        freePageManager.open(fileId);
-        initEmptyTree();
-        freePageManager.close();
-        bufferCache.closeFile(fileId);
-    }
-
-    private void initEmptyTree() throws HyracksDataException {
-        ITreeIndexFrame frame = leafFrameFactory.createFrame();
-        ITreeIndexMetaDataFrame metaFrame = freePageManager.getMetaDataFrameFactory().createFrame();
-        freePageManager.init(metaFrame, rootPage);
-
-        ICachedPage rootNode = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, rootPage), true);
-        rootNode.acquireWriteLatch();
-        try {
-            frame.setPage(rootNode);
-            frame.initBuffer((byte) 0);
-        } finally {
-            rootNode.releaseWriteLatch();
-            bufferCache.unpin(rootNode);
-        }
-    }
-
-    public synchronized void activate() throws HyracksDataException {
-        if (isActivated) {
-            throw new HyracksDataException("Failed to activate the index since it is already activated.");
-        }
-
-        boolean fileIsMapped = false;
-        synchronized (fileMapProvider) {
-            fileIsMapped = fileMapProvider.isMapped(file);
-            if (!fileIsMapped) {
-                bufferCache.createFile(file);
-            }
-            fileId = fileMapProvider.lookupFileId(file);
-            try {
-                // Also creates the file if it doesn't exist yet.
-                bufferCache.openFile(fileId);
-            } catch (HyracksDataException e) {
-                // Revert state of buffer cache since file failed to open.
-                if (!fileIsMapped) {
-                    bufferCache.deleteFile(fileId, false);
-                }
-                throw e;
-            }
-        }
-        freePageManager.open(fileId);
-
-        // TODO: Should probably have some way to check that the tree is physically consistent
-        // or that the file we just opened actually is a tree
-
-        isActivated = true;
-    }
-
-    public synchronized void deactivate() throws HyracksDataException {
-        if (!isActivated) {
-            throw new HyracksDataException("Failed to deactivate the index since it is already deactivated.");
-        }
-
-        bufferCache.closeFile(fileId);
-        freePageManager.close();
-
-        isActivated = false;
-    }
-
-    public synchronized void destroy() throws HyracksDataException {
-        if (isActivated) {
-            throw new HyracksDataException("Failed to destroy the index since it is activated.");
-        }
-
-        file.delete();
-        if (fileId == -1) {
-            return;
-        }
-
-        bufferCache.deleteFile(fileId, false);
-        fileId = -1;
-    }
-
-    public synchronized void clear() throws HyracksDataException {
-        if (!isActivated) {
-            throw new HyracksDataException("Failed to clear the index since it is not activated.");
-        }
-        initEmptyTree();
-    }
-
-    public boolean isEmptyTree(ITreeIndexFrame frame) throws HyracksDataException {
-        ICachedPage rootNode = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, rootPage), false);
-        rootNode.acquireReadLatch();
-        try {
-            frame.setPage(rootNode);
-            if (frame.getLevel() == 0 && frame.getTupleCount() == 0) {
-                return true;
-            } else {
-                return false;
-            }
-        } finally {
-            rootNode.releaseReadLatch();
-            bufferCache.unpin(rootNode);
-        }
-    }
-
-    public byte getTreeHeight(ITreeIndexFrame frame) throws HyracksDataException {
-        ICachedPage rootNode = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, rootPage), false);
-        rootNode.acquireReadLatch();
-        try {
-            frame.setPage(rootNode);
-            return frame.getLevel();
-        } finally {
-            rootNode.releaseReadLatch();
-            bufferCache.unpin(rootNode);
-        }
-    }
-
-    public int getFileId() {
-        return fileId;
-    }
-
-    public FileReference getFileReference() {
-        return file;
-    }
-
-    public IBufferCache getBufferCache() {
-        return bufferCache;
-    }
-
-    public ITreeIndexFrameFactory getInteriorFrameFactory() {
-        return interiorFrameFactory;
-    }
-
-    public ITreeIndexFrameFactory getLeafFrameFactory() {
-        return leafFrameFactory;
-    }
-
-    public IBinaryComparatorFactory[] getComparatorFactories() {
-        return cmpFactories;
-    }
-
-    public IFreePageManager getFreePageManager() {
-        return freePageManager;
-    }
-
-    public int getRootPageId() {
-        return rootPage;
-    }
-
-    public int getFieldCount() {
-        return fieldCount;
-    }
-
-    public abstract class AbstractTreeIndexBulkLoader implements IIndexBulkLoader {
-        protected final MultiComparator cmp;
-        protected final int slotSize;
-        protected final int leafMaxBytes;
-        protected final int interiorMaxBytes;
-        protected final ArrayList<NodeFrontier> nodeFrontiers = new ArrayList<NodeFrontier>();
-        protected final ITreeIndexMetaDataFrame metaFrame;
-        protected final ITreeIndexTupleWriter tupleWriter;
-        protected ITreeIndexFrame leafFrame;
-        protected ITreeIndexFrame interiorFrame;
-
-        public AbstractTreeIndexBulkLoader(float fillFactor) throws TreeIndexException, HyracksDataException {
-            leafFrame = leafFrameFactory.createFrame();
-            interiorFrame = interiorFrameFactory.createFrame();
-            metaFrame = freePageManager.getMetaDataFrameFactory().createFrame();
-
-            if (!isEmptyTree(leafFrame)) {
-                throw new TreeIndexException("Cannot bulk-load a non-empty tree.");
-            }
-
-            this.cmp = MultiComparator.createIgnoreFieldLength(cmpFactories);
-
-            leafFrame.setMultiComparator(cmp);
-            interiorFrame.setMultiComparator(cmp);
-
-            tupleWriter = leafFrame.getTupleWriter();
-
-            NodeFrontier leafFrontier = new NodeFrontier(leafFrame.createTupleReference());
-            leafFrontier.pageId = freePageManager.getFreePage(metaFrame);
-            leafFrontier.page = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, leafFrontier.pageId), true);
-            leafFrontier.page.acquireWriteLatch();
-
-            interiorFrame.setPage(leafFrontier.page);
-            interiorFrame.initBuffer((byte) 0);
-            interiorMaxBytes = (int) ((float) interiorFrame.getBuffer().capacity() * fillFactor);
-
-            leafFrame.setPage(leafFrontier.page);
-            leafFrame.initBuffer((byte) 0);
-            leafMaxBytes = (int) ((float) leafFrame.getBuffer().capacity() * fillFactor);
-            slotSize = leafFrame.getSlotSize();
-
-            nodeFrontiers.add(leafFrontier);
-        }
-
-        public abstract void add(ITupleReference tuple) throws IndexException, HyracksDataException;
-
-        protected void handleException() throws HyracksDataException {
-            // Unlatch and unpin pages.
-            for (NodeFrontier nodeFrontier : nodeFrontiers) {
-                nodeFrontier.page.releaseWriteLatch();
-                bufferCache.unpin(nodeFrontier.page);
-            }
-        }
-
-        @Override
-        public void end() throws HyracksDataException {
-            // copy the root generated from the bulk-load to *the* root page location
-            ICachedPage newRoot = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, rootPage), true);
-            newRoot.acquireWriteLatch();
-            NodeFrontier lastNodeFrontier = nodeFrontiers.get(nodeFrontiers.size() - 1);
-            try {
-                System.arraycopy(lastNodeFrontier.page.getBuffer().array(), 0, newRoot.getBuffer().array(), 0,
-                        lastNodeFrontier.page.getBuffer().capacity());
-            } finally {
-                newRoot.releaseWriteLatch();
-                bufferCache.unpin(newRoot);
-
-                // register old root as a free page
-                freePageManager.addFreePage(metaFrame, lastNodeFrontier.pageId);
-
-                for (int i = 0; i < nodeFrontiers.size(); i++) {
-                    nodeFrontiers.get(i).page.releaseWriteLatch();
-                    bufferCache.unpin(nodeFrontiers.get(i).page);
-                }
-            }
-        }
-
-        protected void addLevel() throws HyracksDataException {
-            NodeFrontier frontier = new NodeFrontier(tupleWriter.createTupleReference());
-            frontier.pageId = freePageManager.getFreePage(metaFrame);
-            frontier.page = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, frontier.pageId), true);
-            frontier.page.acquireWriteLatch();
-            frontier.lastTuple.setFieldCount(cmp.getKeyFieldCount());
-            interiorFrame.setPage(frontier.page);
-            interiorFrame.initBuffer((byte) nodeFrontiers.size());
-            nodeFrontiers.add(frontier);
-        }
-    }
-
-    public class TreeIndexInsertBulkLoader implements IIndexBulkLoader {
-        ITreeIndexAccessor accessor;
-
-        public TreeIndexInsertBulkLoader() throws HyracksDataException {
-            accessor = (ITreeIndexAccessor) createAccessor(NoOpOperationCallback.INSTANCE,
-                    NoOpOperationCallback.INSTANCE);
-        }
-
-        @Override
-        public void add(ITupleReference tuple) throws HyracksDataException {
-            try {
-                accessor.insert(tuple);
-            } catch (IndexException e) {
-                throw new HyracksDataException(e);
-            }
-        }
-
-        @Override
-        public void end() throws HyracksDataException {
-            // do nothing
-        }
-
-    }
-
-    @Override
-    public long getMemoryAllocationSize() {
-        return 0;
-    }
+
+package edu.uci.ics.hyracks.storage.am.common.impls;
+
+import java.util.ArrayList;
+
+import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.io.FileReference;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
+import edu.uci.ics.hyracks.storage.am.common.api.IFreePageManager;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexBulkLoader;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexAccessor;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrame;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrameFactory;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrame;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexTupleWriter;
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
+import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
+import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
+import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPage;
+import edu.uci.ics.hyracks.storage.common.file.BufferedFileHandle;
+import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
+
+public abstract class AbstractTreeIndex implements ITreeIndex {
+
+    protected final static int rootPage = 1;
+
+    protected final IBufferCache bufferCache;
+    protected final IFileMapProvider fileMapProvider;
+    protected final IFreePageManager freePageManager;
+
+    protected final ITreeIndexFrameFactory interiorFrameFactory;
+    protected final ITreeIndexFrameFactory leafFrameFactory;
+
+    protected final IBinaryComparatorFactory[] cmpFactories;
+    protected final int fieldCount;
+
+    protected FileReference file;
+    protected int fileId = -1;
+
+    private boolean isActivated = false;
+
+    public AbstractTreeIndex(IBufferCache bufferCache, IFileMapProvider fileMapProvider,
+            IFreePageManager freePageManager, ITreeIndexFrameFactory interiorFrameFactory,
+            ITreeIndexFrameFactory leafFrameFactory, IBinaryComparatorFactory[] cmpFactories, int fieldCount,
+            FileReference file) {
+        this.bufferCache = bufferCache;
+        this.fileMapProvider = fileMapProvider;
+        this.freePageManager = freePageManager;
+        this.interiorFrameFactory = interiorFrameFactory;
+        this.leafFrameFactory = leafFrameFactory;
+        this.cmpFactories = cmpFactories;
+        this.fieldCount = fieldCount;
+        this.file = file;
+    }
+
+    public synchronized void create() throws HyracksDataException {
+        if (isActivated) {
+            throw new HyracksDataException("Failed to create the index since it is activated.");
+        }
+
+        boolean fileIsMapped = false;
+        synchronized (fileMapProvider) {
+            fileIsMapped = fileMapProvider.isMapped(file);
+            if (!fileIsMapped) {
+                bufferCache.createFile(file);
+            }
+            fileId = fileMapProvider.lookupFileId(file);
+            try {
+                // Also creates the file if it doesn't exist yet.
+                bufferCache.openFile(fileId);
+            } catch (HyracksDataException e) {
+                // Revert state of buffer cache since file failed to open.
+                if (!fileIsMapped) {
+                    bufferCache.deleteFile(fileId, false);
+                }
+                throw e;
+            }
+        }
+
+        freePageManager.open(fileId);
+        initEmptyTree();
+        freePageManager.close();
+        bufferCache.closeFile(fileId);
+    }
+
+    private void initEmptyTree() throws HyracksDataException {
+        ITreeIndexFrame frame = leafFrameFactory.createFrame();
+        ITreeIndexMetaDataFrame metaFrame = freePageManager.getMetaDataFrameFactory().createFrame();
+        freePageManager.init(metaFrame, rootPage);
+
+        ICachedPage rootNode = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, rootPage), true);
+        rootNode.acquireWriteLatch();
+        try {
+            frame.setPage(rootNode);
+            frame.initBuffer((byte) 0);
+        } finally {
+            rootNode.releaseWriteLatch();
+            bufferCache.unpin(rootNode);
+        }
+    }
+
+    public synchronized void activate() throws HyracksDataException {
+        if (isActivated) {
+            throw new HyracksDataException("Failed to activate the index since it is already activated.");
+        }
+
+        boolean fileIsMapped = false;
+        synchronized (fileMapProvider) {
+            fileIsMapped = fileMapProvider.isMapped(file);
+            if (!fileIsMapped) {
+                bufferCache.createFile(file);
+            }
+            fileId = fileMapProvider.lookupFileId(file);
+            try {
+                // Also creates the file if it doesn't exist yet.
+                bufferCache.openFile(fileId);
+            } catch (HyracksDataException e) {
+                // Revert state of buffer cache since file failed to open.
+                if (!fileIsMapped) {
+                    bufferCache.deleteFile(fileId, false);
+                }
+                throw e;
+            }
+        }
+        freePageManager.open(fileId);
+
+        // TODO: Should probably have some way to check that the tree is physically consistent
+        // or that the file we just opened actually is a tree
+
+        isActivated = true;
+    }
+
+    public synchronized void deactivate() throws HyracksDataException {
+        if (!isActivated) {
+            throw new HyracksDataException("Failed to deactivate the index since it is already deactivated.");
+        }
+
+        bufferCache.closeFile(fileId);
+        freePageManager.close();
+
+        isActivated = false;
+    }
+
+    public synchronized void destroy() throws HyracksDataException {
+        if (isActivated) {
+            throw new HyracksDataException("Failed to destroy the index since it is activated.");
+        }
+
+        file.delete();
+        if (fileId == -1) {
+            return;
+        }
+
+        bufferCache.deleteFile(fileId, false);
+        fileId = -1;
+    }
+
+    public synchronized void clear() throws HyracksDataException {
+        if (!isActivated) {
+            throw new HyracksDataException("Failed to clear the index since it is not activated.");
+        }
+        initEmptyTree();
+    }
+
+    public boolean isEmptyTree(ITreeIndexFrame frame) throws HyracksDataException {
+        ICachedPage rootNode = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, rootPage), false);
+        rootNode.acquireReadLatch();
+        try {
+            frame.setPage(rootNode);
+            if (frame.getLevel() == 0 && frame.getTupleCount() == 0) {
+                return true;
+            } else {
+                return false;
+            }
+        } finally {
+            rootNode.releaseReadLatch();
+            bufferCache.unpin(rootNode);
+        }
+    }
+
+    public byte getTreeHeight(ITreeIndexFrame frame) throws HyracksDataException {
+        ICachedPage rootNode = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, rootPage), false);
+        rootNode.acquireReadLatch();
+        try {
+            frame.setPage(rootNode);
+            return frame.getLevel();
+        } finally {
+            rootNode.releaseReadLatch();
+            bufferCache.unpin(rootNode);
+        }
+    }
+
+    public int getFileId() {
+        return fileId;
+    }
+
+    public FileReference getFileReference() {
+        return file;
+    }
+
+    public IBufferCache getBufferCache() {
+        return bufferCache;
+    }
+
+    public ITreeIndexFrameFactory getInteriorFrameFactory() {
+        return interiorFrameFactory;
+    }
+
+    public ITreeIndexFrameFactory getLeafFrameFactory() {
+        return leafFrameFactory;
+    }
+
+    public IBinaryComparatorFactory[] getComparatorFactories() {
+        return cmpFactories;
+    }
+
+    public IFreePageManager getFreePageManager() {
+        return freePageManager;
+    }
+
+    public int getRootPageId() {
+        return rootPage;
+    }
+
+    public int getFieldCount() {
+        return fieldCount;
+    }
+
+    public abstract class AbstractTreeIndexBulkLoader implements IIndexBulkLoader {
+        protected final MultiComparator cmp;
+        protected final int slotSize;
+        protected final int leafMaxBytes;
+        protected final int interiorMaxBytes;
+        protected final ArrayList<NodeFrontier> nodeFrontiers = new ArrayList<NodeFrontier>();
+        protected final ITreeIndexMetaDataFrame metaFrame;
+        protected final ITreeIndexTupleWriter tupleWriter;
+        protected ITreeIndexFrame leafFrame;
+        protected ITreeIndexFrame interiorFrame;
+        private boolean releasedLatches;
+
+        public AbstractTreeIndexBulkLoader(float fillFactor) throws TreeIndexException, HyracksDataException {
+            leafFrame = leafFrameFactory.createFrame();
+            interiorFrame = interiorFrameFactory.createFrame();
+            metaFrame = freePageManager.getMetaDataFrameFactory().createFrame();
+
+            if (!isEmptyTree(leafFrame)) {
+                throw new TreeIndexException("Cannot bulk-load a non-empty tree.");
+            }
+
+            this.cmp = MultiComparator.createIgnoreFieldLength(cmpFactories);
+
+            leafFrame.setMultiComparator(cmp);
+            interiorFrame.setMultiComparator(cmp);
+
+            tupleWriter = leafFrame.getTupleWriter();
+
+            NodeFrontier leafFrontier = new NodeFrontier(leafFrame.createTupleReference());
+            leafFrontier.pageId = freePageManager.getFreePage(metaFrame);
+            leafFrontier.page = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, leafFrontier.pageId), true);
+            leafFrontier.page.acquireWriteLatch();
+
+            interiorFrame.setPage(leafFrontier.page);
+            interiorFrame.initBuffer((byte) 0);
+            interiorMaxBytes = (int) ((float) interiorFrame.getBuffer().capacity() * fillFactor);
+
+            leafFrame.setPage(leafFrontier.page);
+            leafFrame.initBuffer((byte) 0);
+            leafMaxBytes = (int) ((float) leafFrame.getBuffer().capacity() * fillFactor);
+            slotSize = leafFrame.getSlotSize();
+
+            nodeFrontiers.add(leafFrontier);
+        }
+
+        public abstract void add(ITupleReference tuple) throws IndexException, HyracksDataException;
+
+        protected void handleException() throws HyracksDataException {
+            // Unlatch and unpin pages.
+            for (NodeFrontier nodeFrontier : nodeFrontiers) {
+                nodeFrontier.page.releaseWriteLatch();
+                bufferCache.unpin(nodeFrontier.page);
+            }
+            releasedLatches = true;
+        }
+
+        @Override
+        public void end() throws HyracksDataException {
+            // copy the root generated from the bulk-load to *the* root page location
+            ICachedPage newRoot = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, rootPage), true);
+            newRoot.acquireWriteLatch();
+            NodeFrontier lastNodeFrontier = nodeFrontiers.get(nodeFrontiers.size() - 1);
+            try {
+                System.arraycopy(lastNodeFrontier.page.getBuffer().array(), 0, newRoot.getBuffer().array(), 0,
+                        lastNodeFrontier.page.getBuffer().capacity());
+            } finally {
+                newRoot.releaseWriteLatch();
+                bufferCache.unpin(newRoot);
+
+                // register old root as a free page
+                freePageManager.addFreePage(metaFrame, lastNodeFrontier.pageId);
+
+                if (!releasedLatches) {
+                    for (int i = 0; i < nodeFrontiers.size(); i++) {
+                        try {
+                            nodeFrontiers.get(i).page.releaseWriteLatch();
+                        } catch (Exception e) {
+                            //ignore illegal monitor state exception
+                        }
+                        bufferCache.unpin(nodeFrontiers.get(i).page);
+                    }
+                }
+            }
+        }
+
+        protected void addLevel() throws HyracksDataException {
+            NodeFrontier frontier = new NodeFrontier(tupleWriter.createTupleReference());
+            frontier.pageId = freePageManager.getFreePage(metaFrame);
+            frontier.page = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, frontier.pageId), true);
+            frontier.page.acquireWriteLatch();
+            frontier.lastTuple.setFieldCount(cmp.getKeyFieldCount());
+            interiorFrame.setPage(frontier.page);
+            interiorFrame.initBuffer((byte) nodeFrontiers.size());
+            nodeFrontiers.add(frontier);
+        }
+    }
+
+    public class TreeIndexInsertBulkLoader implements IIndexBulkLoader {
+        ITreeIndexAccessor accessor;
+
+        public TreeIndexInsertBulkLoader() throws HyracksDataException {
+            accessor = (ITreeIndexAccessor) createAccessor(NoOpOperationCallback.INSTANCE,
+                    NoOpOperationCallback.INSTANCE);
+        }
+
+        @Override
+        public void add(ITupleReference tuple) throws HyracksDataException {
+            try {
+                accessor.insert(tuple);
+            } catch (IndexException e) {
+                throw new HyracksDataException(e);
+            }
+        }
+
+        @Override
+        public void end() throws HyracksDataException {
+            // do nothing
+        }
+
+    }
+
+    @Override
+    public long getMemoryAllocationSize() {
+        return 0;
+    }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-btree/pom.xml b/hyracks/hyracks-storage-am-lsm-btree/pom.xml
index 158443d..d18210e 100644
--- a/hyracks/hyracks-storage-am-lsm-btree/pom.xml
+++ b/hyracks/hyracks-storage-am-lsm-btree/pom.xml
@@ -19,7 +19,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -39,21 +39,21 @@
     <dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-btree</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency> 
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-bloomfilter</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency> 
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-lsm-common</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>  	
diff --git a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelper.java b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelper.java
index f217419..8a3c313 100644
--- a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelper.java
+++ b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelper.java
@@ -15,13 +15,15 @@
 
 package edu.uci.ics.hyracks.storage.am.lsm.btree.dataflow;
 
+import java.util.List;
+
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.AbstractTreeIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeUtils;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
@@ -31,28 +33,28 @@
 public class LSMBTreeDataflowHelper extends AbstractLSMIndexDataflowHelper {
 
     public LSMBTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            IVirtualBufferCache virtualBufferCache, ILSMMergePolicy mergePolicy,
+            List<IVirtualBufferCache> virtualBufferCaches, ILSMMergePolicy mergePolicy,
             ILSMOperationTrackerProvider opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        this(opDesc, ctx, partition, virtualBufferCache, DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE, mergePolicy,
-                opTrackerFactory, ioScheduler, ioOpCallbackProvider);
+            ILSMIOOperationCallbackFactory ioOpCallbackFactory) {
+        this(opDesc, ctx, partition, virtualBufferCaches, DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE, mergePolicy,
+                opTrackerFactory, ioScheduler, ioOpCallbackFactory);
     }
 
     public LSMBTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            IVirtualBufferCache virtualBufferCache, double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy,
-            ILSMOperationTrackerProvider opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        super(opDesc, ctx, partition, virtualBufferCache, bloomFilterFalsePositiveRate, mergePolicy, opTrackerFactory,
-                ioScheduler, ioOpCallbackProvider);
+            List<IVirtualBufferCache> virtualBufferCaches, double bloomFilterFalsePositiveRate,
+            ILSMMergePolicy mergePolicy, ILSMOperationTrackerProvider opTrackerFactory,
+            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackFactory ioOpCallbackFactory) {
+        super(opDesc, ctx, partition, virtualBufferCaches, bloomFilterFalsePositiveRate, mergePolicy, opTrackerFactory,
+                ioScheduler, ioOpCallbackFactory);
     }
 
     @Override
     public ITreeIndex createIndexInstance() throws HyracksDataException {
         AbstractTreeIndexOperatorDescriptor treeOpDesc = (AbstractTreeIndexOperatorDescriptor) opDesc;
-        return LSMBTreeUtils.createLSMTree(virtualBufferCache, file, opDesc.getStorageManager().getBufferCache(ctx),
+        return LSMBTreeUtils.createLSMTree(virtualBufferCaches, file, opDesc.getStorageManager().getBufferCache(ctx),
                 opDesc.getStorageManager().getFileMapProvider(ctx), treeOpDesc.getTreeIndexTypeTraits(),
                 treeOpDesc.getTreeIndexComparatorFactories(), treeOpDesc.getTreeIndexBloomFilterKeyFields(),
                 bloomFilterFalsePositiveRate, mergePolicy, opTrackerFactory.getOperationTracker(ctx), ioScheduler,
-                ioOpCallbackProvider);
+                ioOpCallbackFactory.createIOOperationCallback());
     }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelperFactory.java b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelperFactory.java
index d331880..104a70d 100644
--- a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelperFactory.java
+++ b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelperFactory.java
@@ -18,7 +18,7 @@
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IndexDataflowHelper;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
@@ -31,18 +31,18 @@
 
     public LSMBTreeDataflowHelperFactory(IVirtualBufferCacheProvider virtualBufferCacheProvider,
             ILSMMergePolicyProvider mergePolicyProvider, ILSMOperationTrackerProvider opTrackerFactory,
-            ILSMIOOperationSchedulerProvider ioSchedulerProvider, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
+            ILSMIOOperationSchedulerProvider ioSchedulerProvider, ILSMIOOperationCallbackFactory ioOpCallbackFactory,
             double bloomFilterFalsePositiveRate) {
         super(virtualBufferCacheProvider, mergePolicyProvider, opTrackerFactory, ioSchedulerProvider,
-                ioOpCallbackProvider, bloomFilterFalsePositiveRate);
+                ioOpCallbackFactory, bloomFilterFalsePositiveRate);
     }
 
     @Override
     public IndexDataflowHelper createIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
             int partition) {
         return new LSMBTreeDataflowHelper(opDesc, ctx, partition,
-                virtualBufferCacheProvider.getVirtualBufferCache(ctx), bloomFilterFalsePositiveRate,
+                virtualBufferCacheProvider.getVirtualBufferCaches(ctx), bloomFilterFalsePositiveRate,
                 mergePolicyProvider.getMergePolicy(ctx), opTrackerFactory, ioSchedulerProvider.getIOScheduler(ctx),
-                ioOpCallbackProvider);
+                ioOpCallbackFactory);
     }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java
index 3557d73..33ae7bb 100644
--- a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java
+++ b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java
@@ -27,7 +27,6 @@
 import edu.uci.ics.hyracks.storage.am.bloomfilter.impls.BloomFilter;
 import edu.uci.ics.hyracks.storage.am.bloomfilter.impls.BloomFilterFactory;
 import edu.uci.ics.hyracks.storage.am.bloomfilter.impls.BloomFilterSpecification;
-import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeDuplicateKeyException;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree.BTreeAccessor;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree.BTreeBulkLoader;
@@ -46,6 +45,7 @@
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
+import edu.uci.ics.hyracks.storage.am.common.exceptions.TreeIndexDuplicateKeyException;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
@@ -67,6 +67,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.AbstractLSMIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BlockingIOOperationCallbackWrapper;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMComponentFileReferences;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMIndexSearchCursor;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMTreeIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.TreeIndexFactory;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
@@ -74,38 +75,42 @@
 
 public class LSMBTree extends AbstractLSMIndex implements ITreeIndex {
 
-    // In-memory components.
-    private final LSMBTreeMutableComponent mutableComponent;
-
     // For creating BTree's used in flush and merge.
-    private final LSMBTreeImmutableComponentFactory componentFactory;
+    private final LSMBTreeDiskComponentFactory componentFactory;
     // For creating BTree's used in bulk load. Different from diskBTreeFactory
     // because it should have a different tuple writer in it's leaf frames.
-    private final LSMBTreeImmutableComponentFactory bulkLoadComponentFactory;
+    private final LSMBTreeDiskComponentFactory bulkLoadComponentFactory;
 
     // Common for in-memory and on-disk components.
     private final ITreeIndexFrameFactory insertLeafFrameFactory;
     private final ITreeIndexFrameFactory deleteLeafFrameFactory;
     private final IBinaryComparatorFactory[] cmpFactories;
 
-    public LSMBTree(IVirtualBufferCache virtualBufferCache, ITreeIndexFrameFactory interiorFrameFactory,
+    public LSMBTree(List<IVirtualBufferCache> virtualBufferCaches, ITreeIndexFrameFactory interiorFrameFactory,
             ITreeIndexFrameFactory insertLeafFrameFactory, ITreeIndexFrameFactory deleteLeafFrameFactory,
             ILSMIndexFileManager fileManager, TreeIndexFactory<BTree> diskBTreeFactory,
             TreeIndexFactory<BTree> bulkLoadBTreeFactory, BloomFilterFactory bloomFilterFactory,
             double bloomFilterFalsePositiveRate, IFileMapProvider diskFileMapProvider, int fieldCount,
             IBinaryComparatorFactory[] cmpFactories, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        super(virtualBufferCache, diskBTreeFactory.getBufferCache(), fileManager, diskFileMapProvider,
-                bloomFilterFalsePositiveRate, mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider);
-        mutableComponent = new LSMBTreeMutableComponent(new BTree(virtualBufferCache,
-                virtualBufferCache.getFileMapProvider(), new VirtualFreePageManager(virtualBufferCache.getNumPages()),
-                interiorFrameFactory, insertLeafFrameFactory, cmpFactories, fieldCount, new FileReference(new File(
-                        fileManager.getBaseDir() + "_virtual"))), virtualBufferCache);
+            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallback ioOpCallback) {
+        super(virtualBufferCaches, diskBTreeFactory.getBufferCache(), fileManager, diskFileMapProvider,
+                bloomFilterFalsePositiveRate, mergePolicy, opTracker, ioScheduler, ioOpCallback);
+        int i = 0;
+        for (IVirtualBufferCache virtualBufferCache : virtualBufferCaches) {
+            LSMBTreeMemoryComponent mutableComponent = new LSMBTreeMemoryComponent(new BTree(virtualBufferCache,
+                    virtualBufferCache.getFileMapProvider(), new VirtualFreePageManager(
+                            virtualBufferCache.getNumPages()), interiorFrameFactory, insertLeafFrameFactory,
+                    cmpFactories, fieldCount, new FileReference(new File(fileManager.getBaseDir() + "_virtual_" + i))),
+                    virtualBufferCache, i == 0 ? true : false);
+            memoryComponents.add(mutableComponent);
+            ++i;
+        }
+
         this.insertLeafFrameFactory = insertLeafFrameFactory;
         this.deleteLeafFrameFactory = deleteLeafFrameFactory;
         this.cmpFactories = cmpFactories;
-        componentFactory = new LSMBTreeImmutableComponentFactory(diskBTreeFactory, bloomFilterFactory);
-        bulkLoadComponentFactory = new LSMBTreeImmutableComponentFactory(bulkLoadBTreeFactory, bloomFilterFactory);
+        componentFactory = new LSMBTreeDiskComponentFactory(diskBTreeFactory, bloomFilterFactory);
+        bulkLoadComponentFactory = new LSMBTreeDiskComponentFactory(bulkLoadBTreeFactory, bloomFilterFactory);
     }
 
     @Override
@@ -116,7 +121,7 @@
 
         fileManager.deleteDirs();
         fileManager.createDirs();
-        componentsRef.get().clear();
+        diskComponents.clear();
     }
 
     @Override
@@ -124,11 +129,13 @@
         if (isActivated) {
             throw new HyracksDataException("Failed to activate the index since it is already activated.");
         }
-
-        ((IVirtualBufferCache) mutableComponent.getBTree().getBufferCache()).open();
-        mutableComponent.getBTree().create();
-        mutableComponent.getBTree().activate();
-        List<ILSMComponent> immutableComponents = componentsRef.get();
+        for (ILSMComponent c : memoryComponents) {
+            LSMBTreeMemoryComponent mutableComponent = (LSMBTreeMemoryComponent) c;
+            ((IVirtualBufferCache) mutableComponent.getBTree().getBufferCache()).open();
+            mutableComponent.getBTree().create();
+            mutableComponent.getBTree().activate();
+        }
+        List<ILSMComponent> immutableComponents = diskComponents;
         immutableComponents.clear();
         List<LSMComponentFileReferences> validFileReferences;
         try {
@@ -137,7 +144,7 @@
             throw new HyracksDataException(e);
         }
         for (LSMComponentFileReferences lsmComonentFileReference : validFileReferences) {
-            LSMBTreeImmutableComponent component;
+            LSMBTreeDiskComponent component;
             try {
                 component = createDiskComponent(componentFactory,
                         lsmComonentFileReference.getInsertIndexFileReference(),
@@ -158,7 +165,7 @@
 
         if (flushOnExit) {
             BlockingIOOperationCallbackWrapper cb = new BlockingIOOperationCallbackWrapper(
-                    ioOpCallbackProvider.getIOOperationCallback(this));
+                    ioOpCallback);
             ILSMIndexAccessor accessor = createAccessor(NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
             accessor.scheduleFlush(cb);
             try {
@@ -168,17 +175,20 @@
             }
         }
 
-        List<ILSMComponent> immutableComponents = componentsRef.get();
+        List<ILSMComponent> immutableComponents = diskComponents;
         for (ILSMComponent c : immutableComponents) {
-            LSMBTreeImmutableComponent component = (LSMBTreeImmutableComponent) c;
+            LSMBTreeDiskComponent component = (LSMBTreeDiskComponent) c;
             BTree btree = component.getBTree();
             BloomFilter bloomFilter = component.getBloomFilter();
             btree.deactivate();
             bloomFilter.deactivate();
         }
-        mutableComponent.getBTree().deactivate();
-        mutableComponent.getBTree().destroy();
-        ((IVirtualBufferCache) mutableComponent.getBTree().getBufferCache()).close();
+        for (ILSMComponent c : memoryComponents) {
+            LSMBTreeMemoryComponent mutableComponent = (LSMBTreeMemoryComponent) c;
+            mutableComponent.getBTree().deactivate();
+            mutableComponent.getBTree().destroy();
+            ((IVirtualBufferCache) mutableComponent.getBTree().getBufferCache()).close();
+        }
         isActivated = false;
     }
 
@@ -193,13 +203,16 @@
             throw new HyracksDataException("Failed to destroy the index since it is activated.");
         }
 
-        List<ILSMComponent> immutableComponents = componentsRef.get();
+        List<ILSMComponent> immutableComponents = diskComponents;
         for (ILSMComponent c : immutableComponents) {
-            LSMBTreeImmutableComponent component = (LSMBTreeImmutableComponent) c;
+            LSMBTreeDiskComponent component = (LSMBTreeDiskComponent) c;
             component.getBTree().destroy();
             component.getBloomFilter().destroy();
         }
-        mutableComponent.getBTree().destroy();
+        for (ILSMComponent c : memoryComponents) {
+            LSMBTreeMemoryComponent mutableComponent = (LSMBTreeMemoryComponent) c;
+            mutableComponent.getBTree().destroy();
+        }
         fileManager.deleteDirs();
     }
 
@@ -209,11 +222,14 @@
             throw new HyracksDataException("Failed to clear the index since it is not activated.");
         }
 
-        List<ILSMComponent> immutableComponents = componentsRef.get();
-        mutableComponent.getBTree().clear();
-        mutableComponent.reset();
+        List<ILSMComponent> immutableComponents = diskComponents;
+        for (ILSMComponent c : memoryComponents) {
+            LSMBTreeMemoryComponent mutableComponent = (LSMBTreeMemoryComponent) c;
+            mutableComponent.getBTree().clear();
+            mutableComponent.reset();
+        }
         for (ILSMComponent c : immutableComponents) {
-            LSMBTreeImmutableComponent component = (LSMBTreeImmutableComponent) c;
+            LSMBTreeDiskComponent component = (LSMBTreeDiskComponent) c;
             component.getBloomFilter().deactivate();
             component.getBTree().deactivate();
             component.getBloomFilter().destroy();
@@ -224,20 +240,32 @@
 
     @Override
     public void getOperationalComponents(ILSMIndexOperationContext ctx) {
-        List<ILSMComponent> immutableComponents = componentsRef.get();
+        List<ILSMComponent> immutableComponents = diskComponents;
         List<ILSMComponent> operationalComponents = ctx.getComponentHolder();
         operationalComponents.clear();
+        int cmc = currentMutableComponentId.get();
+        ctx.setCurrentMutableComponentId(cmc);
+        int numMutableComponents = memoryComponents.size();
         switch (ctx.getOperation()) {
             case UPDATE:
             case UPSERT:
             case PHYSICALDELETE:
             case FLUSH:
             case DELETE:
-                operationalComponents.add(mutableComponent);
+                operationalComponents.add(memoryComponents.get(cmc));
                 break;
             case SEARCH:
             case INSERT:
-                operationalComponents.add(mutableComponent);
+                for (int i = 0; i < numMutableComponents - 1; i++) {
+                    ILSMComponent c = memoryComponents.get((cmc + i + 1) % numMutableComponents);
+                    LSMBTreeMemoryComponent mutableComponent = (LSMBTreeMemoryComponent) c;
+                    if (mutableComponent.isReadable()) {
+                        // Make sure newest components are added first
+                        operationalComponents.add(0, mutableComponent);
+                    }
+                }
+                // The current mutable component is always added
+                operationalComponents.add(0, memoryComponents.get(cmc));
                 operationalComponents.addAll(immutableComponents);
                 break;
             case MERGE:
@@ -253,36 +281,38 @@
         LSMBTreeOpContext ctx = (LSMBTreeOpContext) ictx;
         switch (ctx.getOperation()) {
             case PHYSICALDELETE:
-                ctx.memBTreeAccessor.delete(tuple);
+                ctx.currentMutableBTreeAccessor.delete(tuple);
                 break;
             case INSERT:
                 insert(tuple, ctx);
                 break;
             default:
-                ctx.memBTreeAccessor.upsert(tuple);
+                ctx.currentMutableBTreeAccessor.upsert(tuple);
                 break;
         }
-        mutableComponent.setIsModified();
     }
 
     private boolean insert(ITupleReference tuple, LSMBTreeOpContext ctx) throws HyracksDataException, IndexException {
+        ILSMComponent c = ctx.getComponentHolder().get(0);
+        LSMBTreeMemoryComponent mutableComponent = (LSMBTreeMemoryComponent) c;
         MultiComparator comparator = MultiComparator.createIgnoreFieldLength(mutableComponent.getBTree()
                 .getComparatorFactories());
         LSMBTreePointSearchCursor searchCursor = new LSMBTreePointSearchCursor(ctx);
-        IIndexCursor memCursor = new BTreeRangeSearchCursor(ctx.memBTreeOpCtx.leafFrame, false);
+        IIndexCursor memCursor = new BTreeRangeSearchCursor(ctx.currentMutableBTreeOpCtx.leafFrame, false);
         RangePredicate predicate = new RangePredicate(tuple, tuple, true, true, comparator, comparator);
 
         // first check the inmemory component
-        ctx.memBTreeAccessor.search(memCursor, predicate);
+        ctx.currentMutableBTreeAccessor.search(memCursor, predicate);
         try {
             if (memCursor.hasNext()) {
                 memCursor.next();
                 LSMBTreeTupleReference lsmbtreeTuple = (LSMBTreeTupleReference) memCursor.getTuple();
                 if (!lsmbtreeTuple.isAntimatter()) {
-                    throw new BTreeDuplicateKeyException("Failed to insert key since key already exists.");
+                    throw new TreeIndexDuplicateKeyException("Failed to insert key since key already exists.");
                 } else {
                     memCursor.close();
-                    ctx.memBTreeAccessor.upsertIfConditionElseInsert(tuple, AntimatterAwareTupleAcceptor.INSTANCE);
+                    ctx.currentMutableBTreeAccessor.upsertIfConditionElseInsert(tuple,
+                            AntimatterAwareTupleAcceptor.INSTANCE);
                     return true;
                 }
             }
@@ -296,16 +326,21 @@
         // the mutable component?
         // the key was not in the inmemory component, so check the disk
         // components
+
+        // This is a hack to avoid searching the current active mutable component twice. It is critical to add it back once the search is over.
+        ILSMComponent firstComponent = ctx.getComponentHolder().remove(0);
         search(ctx, searchCursor, predicate);
         try {
             if (searchCursor.hasNext()) {
-                throw new BTreeDuplicateKeyException("Failed to insert key since key already exists.");
+                throw new TreeIndexDuplicateKeyException("Failed to insert key since key already exists.");
             }
         } finally {
             searchCursor.close();
+            // Add the current active mutable component back
+            ctx.getComponentHolder().add(0, firstComponent);
         }
-        ctx.memBTreeAccessor.upsertIfConditionElseInsert(tuple, AntimatterAwareTupleAcceptor.INSTANCE);
 
+        ctx.currentMutableBTreeAccessor.upsertIfConditionElseInsert(tuple, AntimatterAwareTupleAcceptor.INSTANCE);
         return true;
     }
 
@@ -314,38 +349,30 @@
             throws HyracksDataException, IndexException {
         LSMBTreeOpContext ctx = (LSMBTreeOpContext) ictx;
         List<ILSMComponent> operationalComponents = ctx.getComponentHolder();
-        int numBTrees = operationalComponents.size();
-        assert numBTrees > 0;
 
-        boolean includeMutableComponent = operationalComponents.get(0) == mutableComponent;
-        LSMBTreeCursorInitialState initialState = new LSMBTreeCursorInitialState(numBTrees, insertLeafFrameFactory,
-                ctx.cmp, ctx.bloomFilterCmp, includeMutableComponent, lsmHarness, ctx.memBTreeAccessor, pred,
-                ctx.searchCallback, operationalComponents);
+        LSMBTreeCursorInitialState initialState = new LSMBTreeCursorInitialState(insertLeafFrameFactory, ctx.cmp,
+                ctx.bloomFilterCmp, lsmHarness, pred, ctx.searchCallback, operationalComponents);
         cursor.open(initialState, pred);
     }
 
     @Override
-    public boolean scheduleFlush(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
+    public void scheduleFlush(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
             throws HyracksDataException {
-        if (!mutableComponent.isModified()) {
-            return false;
-        }
+        ILSMComponent flushingComponent = ctx.getComponentHolder().get(0);
         LSMComponentFileReferences componentFileRefs = fileManager.getRelFlushFileReference();
         LSMBTreeOpContext opCtx = createOpContext(NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
         assert ctx.getComponentHolder().size() == 1;
-        ILSMComponent flushingComponent = ctx.getComponentHolder().get(0);
         opCtx.setOperation(IndexOperation.FLUSH);
         opCtx.getComponentHolder().add(flushingComponent);
         ILSMIndexAccessorInternal flushAccessor = new LSMBTreeAccessor(lsmHarness, opCtx);
         ioScheduler.scheduleOperation(new LSMBTreeFlushOperation(flushAccessor, flushingComponent, componentFileRefs
                 .getInsertIndexFileReference(), componentFileRefs.getBloomFilterFileReference(), callback));
-        return true;
     }
 
     @Override
     public ILSMComponent flush(ILSMIOOperation operation) throws HyracksDataException, IndexException {
         LSMBTreeFlushOperation flushOp = (LSMBTreeFlushOperation) operation;
-        LSMBTreeMutableComponent flushingComponent = (LSMBTreeMutableComponent) flushOp.getFlushingComponent();
+        LSMBTreeMemoryComponent flushingComponent = (LSMBTreeMemoryComponent) flushOp.getFlushingComponent();
         IIndexAccessor accessor = flushingComponent.getBTree().createAccessor(NoOpOperationCallback.INSTANCE,
                 NoOpOperationCallback.INSTANCE);
 
@@ -368,7 +395,7 @@
         BloomFilterSpecification bloomFilterSpec = BloomCalculations.computeBloomSpec(maxBucketsPerElement,
                 bloomFilterFalsePositiveRate);
 
-        LSMBTreeImmutableComponent component = createDiskComponent(componentFactory, flushOp.getBTreeFlushTarget(),
+        LSMBTreeDiskComponent component = createDiskComponent(componentFactory, flushOp.getBTreeFlushTarget(),
                 flushOp.getBloomFilterFlushTarget(), true);
         IIndexBulkLoader bulkLoader = component.getBTree().createBulkLoader(1.0f, false, numElements, false);
         IIndexBulkLoader builder = component.getBloomFilter().createBuilder(numElements,
@@ -390,18 +417,16 @@
         return component;
     }
 
+    @Override
     public void scheduleMerge(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
             throws HyracksDataException, IndexException {
         LSMBTreeOpContext opCtx = createOpContext(NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
-        List<ILSMComponent> mergingComponents = ctx.getComponentHolder();
-        opCtx.getComponentHolder().addAll(mergingComponents);
-        ITreeIndexCursor cursor = new LSMBTreeRangeSearchCursor(opCtx);
-        RangePredicate rangePred = new RangePredicate(null, null, true, true, null, null);
-        search(opCtx, cursor, rangePred);
-
         opCtx.setOperation(IndexOperation.MERGE);
-        BTree firstBTree = (BTree) ((LSMBTreeImmutableComponent) mergingComponents.get(0)).getBTree();
-        BTree lastBTree = (BTree) ((LSMBTreeImmutableComponent) mergingComponents.get(mergingComponents.size() - 1))
+        List<ILSMComponent> mergingComponents = ctx.getComponentHolder();
+        ITreeIndexCursor cursor = new LSMBTreeRangeSearchCursor(opCtx);
+
+        BTree firstBTree = (BTree) ((LSMBTreeDiskComponent) mergingComponents.get(0)).getBTree();
+        BTree lastBTree = (BTree) ((LSMBTreeDiskComponent) mergingComponents.get(mergingComponents.size() - 1))
                 .getBTree();
         FileReference firstFile = diskFileMapProvider.lookupFileName(firstBTree.getFileId());
         FileReference lastFile = diskFileMapProvider.lookupFileName(lastBTree.getFileId());
@@ -413,21 +438,24 @@
     }
 
     @Override
-    public ILSMComponent merge(List<ILSMComponent> mergedComponents, ILSMIOOperation operation)
-            throws HyracksDataException, IndexException {
+    public ILSMComponent merge(ILSMIOOperation operation) throws HyracksDataException, IndexException {
         LSMBTreeMergeOperation mergeOp = (LSMBTreeMergeOperation) operation;
         ITreeIndexCursor cursor = mergeOp.getCursor();
-        mergedComponents.addAll(mergeOp.getMergingComponents());
+        RangePredicate rangePred = new RangePredicate(null, null, true, true, null, null);
+        ILSMIndexOperationContext opCtx = ((LSMIndexSearchCursor) cursor).getOpCtx();
+        opCtx.getComponentHolder().addAll(mergeOp.getMergingComponents());
+        search(opCtx, cursor, rangePred);
+        List<ILSMComponent> mergedComponents = mergeOp.getMergingComponents();
 
         long numElements = 0L;
         for (int i = 0; i < mergedComponents.size(); ++i) {
-            numElements += ((LSMBTreeImmutableComponent) mergedComponents.get(i)).getBloomFilter().getNumElements();
+            numElements += ((LSMBTreeDiskComponent) mergedComponents.get(i)).getBloomFilter().getNumElements();
         }
 
         int maxBucketsPerElement = BloomCalculations.maxBucketsPerElement(numElements);
         BloomFilterSpecification bloomFilterSpec = BloomCalculations.computeBloomSpec(maxBucketsPerElement,
                 bloomFilterFalsePositiveRate);
-        LSMBTreeImmutableComponent mergedComponent = createDiskComponent(componentFactory,
+        LSMBTreeDiskComponent mergedComponent = createDiskComponent(componentFactory,
                 mergeOp.getBTreeMergeTarget(), mergeOp.getBloomFilterMergeTarget(), true);
 
         IIndexBulkLoader bulkLoader = mergedComponent.getBTree().createBulkLoader(1.0f, false, numElements, false);
@@ -448,11 +476,11 @@
         return mergedComponent;
     }
 
-    private LSMBTreeImmutableComponent createDiskComponent(LSMBTreeImmutableComponentFactory factory,
+    private LSMBTreeDiskComponent createDiskComponent(LSMBTreeDiskComponentFactory factory,
             FileReference btreeFileRef, FileReference bloomFilterFileRef, boolean createComponent)
             throws HyracksDataException, IndexException {
         // Create new BTree instance.
-        LSMBTreeImmutableComponent component = (LSMBTreeImmutableComponent) factory
+        LSMBTreeDiskComponent component = (LSMBTreeDiskComponent) factory
                 .createLSMComponentInstance(new LSMComponentFileReferences(btreeFileRef, null, bloomFilterFileRef));
         if (createComponent) {
             component.getBTree().create();
@@ -484,7 +512,7 @@
     public void markAsValid(ILSMComponent lsmComponent) throws HyracksDataException {
         // The order of forcing the dirty page to be flushed is critical. The
         // bloom filter must be always done first.
-        LSMBTreeImmutableComponent component = (LSMBTreeImmutableComponent) lsmComponent;
+        LSMBTreeDiskComponent component = (LSMBTreeDiskComponent) lsmComponent;
         // Flush the bloom filter first.
         int fileId = component.getBloomFilter().getFileId();
         IBufferCache bufferCache = component.getBTree().getBufferCache();
@@ -513,13 +541,13 @@
             } catch (HyracksDataException | IndexException e) {
                 throw new TreeIndexException(e);
             }
-            bulkLoader = (BTreeBulkLoader) ((LSMBTreeImmutableComponent) component).getBTree().createBulkLoader(
+            bulkLoader = (BTreeBulkLoader) ((LSMBTreeDiskComponent) component).getBTree().createBulkLoader(
                     fillFactor, verifyInput, numElementsHint, false);
 
             int maxBucketsPerElement = BloomCalculations.maxBucketsPerElement(numElementsHint);
             BloomFilterSpecification bloomFilterSpec = BloomCalculations.computeBloomSpec(maxBucketsPerElement,
                     bloomFilterFalsePositiveRate);
-            builder = ((LSMBTreeImmutableComponent) component).getBloomFilter().createBuilder(numElementsHint,
+            builder = ((LSMBTreeDiskComponent) component).getBloomFilter().createBuilder(numElementsHint,
                     bloomFilterSpec.getNumHashes(), bloomFilterSpec.getNumBucketsPerElements());
         }
 
@@ -545,10 +573,10 @@
                     builder.end();
                     endedBloomFilterLoad = true;
                 }
-                ((LSMBTreeImmutableComponent) component).getBTree().deactivate();
-                ((LSMBTreeImmutableComponent) component).getBTree().destroy();
-                ((LSMBTreeImmutableComponent) component).getBloomFilter().deactivate();
-                ((LSMBTreeImmutableComponent) component).getBloomFilter().destroy();
+                ((LSMBTreeDiskComponent) component).getBTree().deactivate();
+                ((LSMBTreeDiskComponent) component).getBTree().destroy();
+                ((LSMBTreeDiskComponent) component).getBloomFilter().deactivate();
+                ((LSMBTreeDiskComponent) component).getBloomFilter().destroy();
             }
         }
 
@@ -571,7 +599,7 @@
 
     public LSMBTreeOpContext createOpContext(IModificationOperationCallback modificationCallback,
             ISearchOperationCallback searchCallback) {
-        return new LSMBTreeOpContext(mutableComponent.getBTree(), insertLeafFrameFactory, deleteLeafFrameFactory,
+        return new LSMBTreeOpContext(memoryComponents, insertLeafFrameFactory, deleteLeafFrameFactory,
                 modificationCallback, searchCallback, componentFactory.getBloomFilterKeyFields().length);
     }
 
@@ -608,50 +636,66 @@
 
     @Override
     public ITreeIndexFrameFactory getInteriorFrameFactory() {
+        LSMBTreeMemoryComponent mutableComponent = (LSMBTreeMemoryComponent) memoryComponents
+                .get(currentMutableComponentId.get());
         return mutableComponent.getBTree().getInteriorFrameFactory();
     }
 
     @Override
     public int getFieldCount() {
+        LSMBTreeMemoryComponent mutableComponent = (LSMBTreeMemoryComponent) memoryComponents
+                .get(currentMutableComponentId.get());
         return mutableComponent.getBTree().getFieldCount();
     }
 
     @Override
     public int getFileId() {
+        LSMBTreeMemoryComponent mutableComponent = (LSMBTreeMemoryComponent) memoryComponents
+                .get(currentMutableComponentId.get());
         return mutableComponent.getBTree().getFileId();
     }
 
     @Override
     public IFreePageManager getFreePageManager() {
+        LSMBTreeMemoryComponent mutableComponent = (LSMBTreeMemoryComponent) memoryComponents
+                .get(currentMutableComponentId.get());
         return mutableComponent.getBTree().getFreePageManager();
     }
 
     @Override
     public ITreeIndexFrameFactory getLeafFrameFactory() {
+        LSMBTreeMemoryComponent mutableComponent = (LSMBTreeMemoryComponent) memoryComponents
+                .get(currentMutableComponentId.get());
         return mutableComponent.getBTree().getLeafFrameFactory();
     }
 
     @Override
     public long getMemoryAllocationSize() {
-        IBufferCache virtualBufferCache = mutableComponent.getBTree().getBufferCache();
-        return virtualBufferCache.getNumPages() * virtualBufferCache.getPageSize();
+        long size = 0;
+        for (ILSMComponent c : memoryComponents) {
+            LSMBTreeMemoryComponent mutableComponent = (LSMBTreeMemoryComponent) c;
+            IBufferCache virtualBufferCache = mutableComponent.getBTree().getBufferCache();
+            size += virtualBufferCache.getNumPages() * virtualBufferCache.getPageSize();
+        }
+        return size;
     }
 
     @Override
     public int getRootPageId() {
+        LSMBTreeMemoryComponent mutableComponent = (LSMBTreeMemoryComponent) memoryComponents
+                .get(currentMutableComponentId.get());
         return mutableComponent.getBTree().getRootPageId();
     }
 
-    public boolean isEmptyIndex() throws HyracksDataException {
-        return componentsRef.get().isEmpty() && !mutableComponent.isModified();
-    }
-
     @Override
     public void validate() throws HyracksDataException {
-        mutableComponent.getBTree().validate();
-        List<ILSMComponent> immutableComponents = componentsRef.get();
+        for (ILSMComponent c : memoryComponents) {
+            LSMBTreeMemoryComponent mutableComponent = (LSMBTreeMemoryComponent) c;
+            mutableComponent.getBTree().validate();
+        }
+        List<ILSMComponent> immutableComponents = diskComponents;
         for (ILSMComponent c : immutableComponents) {
-            BTree btree = (BTree) ((LSMBTreeImmutableComponent) c).getBTree();
+            BTree btree = (BTree) ((LSMBTreeDiskComponent) c).getBTree();
             btree.validate();
         }
     }
diff --git a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeCursorInitialState.java b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeCursorInitialState.java
index b5c6a45..37f89ff 100644
--- a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeCursorInitialState.java
+++ b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeCursorInitialState.java
@@ -18,7 +18,6 @@
 import java.util.List;
 
 import edu.uci.ics.hyracks.storage.am.common.api.ICursorInitialState;
-import edu.uci.ics.hyracks.storage.am.common.api.IIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.common.api.ISearchOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.api.ISearchPredicate;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrameFactory;
@@ -29,39 +28,28 @@
 
 public class LSMBTreeCursorInitialState implements ICursorInitialState {
 
-    private final int numBTrees;
     private final ITreeIndexFrameFactory leafFrameFactory;
     private MultiComparator cmp;
     private final MultiComparator bloomFilterCmp;
-    private final boolean includeMemComponent;
     private final ILSMHarness lsmHarness;
 
-    private final IIndexAccessor memBtreeAccessor;
     private final ISearchPredicate predicate;
     private ISearchOperationCallback searchCallback;
 
     private final List<ILSMComponent> operationalComponents;
 
-    public LSMBTreeCursorInitialState(int numBTrees, ITreeIndexFrameFactory leafFrameFactory, MultiComparator cmp,
-            MultiComparator bloomFilterCmp, boolean includeMemComponent, ILSMHarness lsmHarness,
-            IIndexAccessor memBtreeAccessor, ISearchPredicate predicate, ISearchOperationCallback searchCallback,
-            List<ILSMComponent> operationalComponents) {
-        this.numBTrees = numBTrees;
+    public LSMBTreeCursorInitialState(ITreeIndexFrameFactory leafFrameFactory, MultiComparator cmp,
+            MultiComparator bloomFilterCmp, ILSMHarness lsmHarness, ISearchPredicate predicate,
+            ISearchOperationCallback searchCallback, List<ILSMComponent> operationalComponents) {
         this.leafFrameFactory = leafFrameFactory;
         this.cmp = cmp;
         this.bloomFilterCmp = bloomFilterCmp;
-        this.includeMemComponent = includeMemComponent;
         this.lsmHarness = lsmHarness;
         this.searchCallback = searchCallback;
-        this.memBtreeAccessor = memBtreeAccessor;
         this.predicate = predicate;
         this.operationalComponents = operationalComponents;
     }
 
-    public int getNumBTrees() {
-        return numBTrees;
-    }
-
     public ITreeIndexFrameFactory getLeafFrameFactory() {
         return leafFrameFactory;
     }
@@ -75,10 +63,6 @@
     public void setPage(ICachedPage page) {
     }
 
-    public boolean getIncludeMemComponent() {
-        return includeMemComponent;
-    }
-
     public ILSMHarness getLSMHarness() {
         return lsmHarness;
     }
@@ -97,10 +81,6 @@
         return operationalComponents;
     }
 
-    public IIndexAccessor getMemBTreeAccessor() {
-        return memBtreeAccessor;
-    }
-
     public ISearchPredicate getSearchPredicate() {
         return predicate;
     }
diff --git a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeImmutableComponent.java b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeDiskComponent.java
similarity index 84%
rename from hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeImmutableComponent.java
rename to hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeDiskComponent.java
index affdef8..0b2d7cf 100644
--- a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeImmutableComponent.java
+++ b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeDiskComponent.java
@@ -17,13 +17,13 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.am.bloomfilter.impls.BloomFilter;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.AbstractImmutableLSMComponent;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.AbstractDiskLSMComponent;
 
-public class LSMBTreeImmutableComponent extends AbstractImmutableLSMComponent {
+public class LSMBTreeDiskComponent extends AbstractDiskLSMComponent {
     private final BTree btree;
     private final BloomFilter bloomFilter;
 
-    public LSMBTreeImmutableComponent(BTree btree, BloomFilter bloomFilter) {
+    public LSMBTreeDiskComponent(BTree btree, BloomFilter bloomFilter) {
         this.btree = btree;
         this.bloomFilter = bloomFilter;
     }
diff --git a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeImmutableComponentFactory.java b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeDiskComponentFactory.java
similarity index 86%
rename from hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeImmutableComponentFactory.java
rename to hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeDiskComponentFactory.java
index 0efdc65..7b1e0de 100644
--- a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeImmutableComponentFactory.java
+++ b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeDiskComponentFactory.java
@@ -25,11 +25,11 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.TreeIndexFactory;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 
-public class LSMBTreeImmutableComponentFactory implements ILSMComponentFactory {
+public class LSMBTreeDiskComponentFactory implements ILSMComponentFactory {
     private final TreeIndexFactory<BTree> btreeFactory;
     private final BloomFilterFactory bloomFilterFactory;
 
-    public LSMBTreeImmutableComponentFactory(TreeIndexFactory<BTree> btreeFactory, BloomFilterFactory bloomFilterFactory) {
+    public LSMBTreeDiskComponentFactory(TreeIndexFactory<BTree> btreeFactory, BloomFilterFactory bloomFilterFactory) {
         this.btreeFactory = btreeFactory;
         this.bloomFilterFactory = bloomFilterFactory;
     }
@@ -37,7 +37,7 @@
     @Override
     public ILSMComponent createLSMComponentInstance(LSMComponentFileReferences cfr) throws IndexException,
             HyracksDataException {
-        return new LSMBTreeImmutableComponent(btreeFactory.createIndexInstance(cfr.getInsertIndexFileReference()),
+        return new LSMBTreeDiskComponent(btreeFactory.createIndexInstance(cfr.getInsertIndexFileReference()),
                 bloomFilterFactory.createBloomFiltertInstance(cfr.getBloomFilterFileReference()));
     }
 
diff --git a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeFlushOperation.java b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeFlushOperation.java
index 1aab213..668e727 100644
--- a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeFlushOperation.java
+++ b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeFlushOperation.java
@@ -58,8 +58,9 @@
     }
 
     @Override
-    public void perform() throws HyracksDataException, IndexException {
+    public Boolean call() throws HyracksDataException, IndexException {
         accessor.flush(this);
+        return true;
     }
 
     @Override
diff --git a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeMutableComponent.java b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeMemoryComponent.java
similarity index 79%
rename from hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeMutableComponent.java
rename to hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeMemoryComponent.java
index 0f3e3ce..7550349 100644
--- a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeMutableComponent.java
+++ b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeMemoryComponent.java
@@ -18,16 +18,15 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.AbstractMutableLSMComponent;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.AbstractMemoryLSMComponent;
 
-public class LSMBTreeMutableComponent extends AbstractMutableLSMComponent {
+public class LSMBTreeMemoryComponent extends AbstractMemoryLSMComponent {
 
     private final BTree btree;
-    private final IVirtualBufferCache vbc;
 
-    public LSMBTreeMutableComponent(BTree btree, IVirtualBufferCache vbc) {
+    public LSMBTreeMemoryComponent(BTree btree, IVirtualBufferCache vbc, boolean isActive) {
+        super(vbc, isActive);
         this.btree = btree;
-        this.vbc = vbc;
     }
 
     public BTree getBTree() {
@@ -35,11 +34,6 @@
     }
 
     @Override
-    protected boolean isFull() {
-        return vbc.isFull();
-    }
-
-    @Override
     protected void reset() throws HyracksDataException {
         super.reset();
         btree.deactivate();
diff --git a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeMergeOperation.java b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeMergeOperation.java
index fd3f1fd..3a608fe 100644
--- a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeMergeOperation.java
+++ b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeMergeOperation.java
@@ -53,7 +53,7 @@
     public Set<IODeviceHandle> getReadDevices() {
         Set<IODeviceHandle> devs = new HashSet<IODeviceHandle>();
         for (ILSMComponent o : mergingComponents) {
-            LSMBTreeImmutableComponent component = (LSMBTreeImmutableComponent) o;
+            LSMBTreeDiskComponent component = (LSMBTreeDiskComponent) o;
             devs.add(component.getBTree().getFileReference().getDeviceHandle());
             devs.add(component.getBloomFilter().getFileReference().getDeviceHandle());
         }
@@ -69,8 +69,9 @@
     }
 
     @Override
-    public void perform() throws HyracksDataException, IndexException {
+    public Boolean call() throws HyracksDataException, IndexException {
         accessor.merge(this);
+        return true;
     }
 
     @Override
diff --git a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeOpContext.java b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeOpContext.java
index ac62d9f..6d2d7c0 100644
--- a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeOpContext.java
+++ b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeOpContext.java
@@ -37,9 +37,11 @@
     public ITreeIndexFrameFactory deleteLeafFrameFactory;
     public IBTreeLeafFrame insertLeafFrame;
     public IBTreeLeafFrame deleteLeafFrame;
-    public final BTree memBTree;
-    public BTree.BTreeAccessor memBTreeAccessor;
-    public BTreeOpContext memBTreeOpCtx;
+    public final BTree[] mutableBTrees;
+    public BTree.BTreeAccessor[] mutableBTreeAccessors;
+    public BTreeOpContext[] mutableBTreeOpCtxs;
+    public BTree.BTreeAccessor currentMutableBTreeAccessor;
+    public BTreeOpContext currentMutableBTreeOpCtx;
     public IndexOperation op;
     public final MultiComparator cmp;
     public final MultiComparator bloomFilterCmp;
@@ -47,19 +49,30 @@
     public final ISearchOperationCallback searchCallback;
     private final List<ILSMComponent> componentHolder;
 
-    public LSMBTreeOpContext(BTree memBTree, ITreeIndexFrameFactory insertLeafFrameFactory,
+    public LSMBTreeOpContext(List<ILSMComponent> mutableComponents, ITreeIndexFrameFactory insertLeafFrameFactory,
             ITreeIndexFrameFactory deleteLeafFrameFactory, IModificationOperationCallback modificationCallback,
             ISearchOperationCallback searchCallback, int numBloomFilterKeyFields) {
-        IBinaryComparatorFactory cmpFactories[] = memBTree.getComparatorFactories();
+        LSMBTreeMemoryComponent c = (LSMBTreeMemoryComponent) mutableComponents.get(0);
+        IBinaryComparatorFactory cmpFactories[] = c.getBTree().getComparatorFactories();
         if (cmpFactories[0] != null) {
-            this.cmp = MultiComparator.create(memBTree.getComparatorFactories());
+            this.cmp = MultiComparator.create(c.getBTree().getComparatorFactories());
         } else {
             this.cmp = null;
         }
 
-        bloomFilterCmp = MultiComparator.create(memBTree.getComparatorFactories(), 0, numBloomFilterKeyFields);
+        bloomFilterCmp = MultiComparator.create(c.getBTree().getComparatorFactories(), 0, numBloomFilterKeyFields);
 
-        this.memBTree = memBTree;
+        mutableBTrees = new BTree[mutableComponents.size()];
+        mutableBTreeAccessors = new BTree.BTreeAccessor[mutableComponents.size()];
+        mutableBTreeOpCtxs = new BTreeOpContext[mutableComponents.size()];
+        for (int i = 0; i < mutableComponents.size(); i++) {
+            LSMBTreeMemoryComponent mutableComponent = (LSMBTreeMemoryComponent) mutableComponents.get(i);
+            mutableBTrees[i] = mutableComponent.getBTree();
+            mutableBTreeAccessors[i] = (BTree.BTreeAccessor) mutableBTrees[i].createAccessor(modificationCallback,
+                    NoOpOperationCallback.INSTANCE);
+            mutableBTreeOpCtxs[i] = mutableBTreeAccessors[i].getOpContext();
+        }
+
         this.insertLeafFrameFactory = insertLeafFrameFactory;
         this.deleteLeafFrameFactory = deleteLeafFrameFactory;
         this.insertLeafFrame = (IBTreeLeafFrame) insertLeafFrameFactory.createFrame();
@@ -79,48 +92,16 @@
     public void setOperation(IndexOperation newOp) {
         reset();
         this.op = newOp;
-        switch (newOp) {
-            case SEARCH:
-                setMemBTreeAccessor();
-                break;
-            case DISKORDERSCAN:
-            case UPDATE:
-                // Attention: It is important to leave the leafFrame and
-                // leafFrameFactory of the memBTree as is when doing an update.
-                // Update will only be set if a previous attempt to delete or
-                // insert failed, so we must preserve the semantics of the
-                // previously requested operation.
-                setMemBTreeAccessor();
-                return;
-            case UPSERT:
-            case INSERT:
-                setInsertMode();
-                break;
-            case PHYSICALDELETE:
-            case DELETE:
-                setDeleteMode();
-                break;
-        }
-    }
-
-    private void setMemBTreeAccessor() {
-        if (memBTreeAccessor == null) {
-            memBTreeAccessor = (BTree.BTreeAccessor) memBTree.createAccessor(modificationCallback,
-                    NoOpOperationCallback.INSTANCE);
-            memBTreeOpCtx = memBTreeAccessor.getOpContext();
-        }
     }
 
     public void setInsertMode() {
-        setMemBTreeAccessor();
-        memBTreeOpCtx.leafFrame = insertLeafFrame;
-        memBTreeOpCtx.leafFrameFactory = insertLeafFrameFactory;
+        currentMutableBTreeOpCtx.leafFrame = insertLeafFrame;
+        currentMutableBTreeOpCtx.leafFrameFactory = insertLeafFrameFactory;
     }
 
     public void setDeleteMode() {
-        setMemBTreeAccessor();
-        memBTreeOpCtx.leafFrame = deleteLeafFrame;
-        memBTreeOpCtx.leafFrameFactory = deleteLeafFrameFactory;
+        currentMutableBTreeOpCtx.leafFrame = deleteLeafFrame;
+        currentMutableBTreeOpCtx.leafFrameFactory = deleteLeafFrameFactory;
     }
 
     @Override
@@ -146,4 +127,30 @@
     public IModificationOperationCallback getModificationCallback() {
         return modificationCallback;
     }
+
+    @Override
+    public void setCurrentMutableComponentId(int currentMutableComponentId) {
+        currentMutableBTreeAccessor = mutableBTreeAccessors[currentMutableComponentId];
+        currentMutableBTreeOpCtx = mutableBTreeOpCtxs[currentMutableComponentId];
+        switch (op) {
+            case SEARCH:
+                break;
+            case DISKORDERSCAN:
+            case UPDATE:
+                // Attention: It is important to leave the leafFrame and
+                // leafFrameFactory of the mutableBTree as is when doing an update.
+                // Update will only be set if a previous attempt to delete or
+                // insert failed, so we must preserve the semantics of the
+                // previously requested operation.
+                break;
+            case UPSERT:
+            case INSERT:
+                setInsertMode();
+                break;
+            case PHYSICALDELETE:
+            case DELETE:
+                setDeleteMode();
+                break;
+        }
+    }
 }
\ No newline at end of file
diff --git a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreePointSearchCursor.java b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreePointSearchCursor.java
index 64e0c28..fc09a74 100644
--- a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreePointSearchCursor.java
+++ b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreePointSearchCursor.java
@@ -15,7 +15,7 @@
 
 package edu.uci.ics.hyracks.storage.am.lsm.btree.impls;
 
-import java.util.ListIterator;
+import java.util.List;
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
@@ -32,6 +32,7 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent.LSMComponentType;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMHarness;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexOperationContext;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMTreeTupleReference;
@@ -45,14 +46,14 @@
     private final ILSMIndexOperationContext opCtx;
     private ISearchOperationCallback searchCallback;
     private RangePredicate predicate;
-    private IIndexAccessor memBTreeAccessor;
-    private boolean includeMemComponent;
+    private boolean includeMutableComponent;
     private int numBTrees;
-    private IIndexAccessor[] bTreeAccessors;
+    private IIndexAccessor[] btreeAccessors;
     private ILSMHarness lsmHarness;
     private boolean nextHasBeenCalled;
     private boolean foundTuple;
     private ITupleReference frameTuple;
+    private List<ILSMComponent> operationalComponents;
 
     public LSMBTreePointSearchCursor(ILSMIndexOperationContext opCtx) {
         this.opCtx = opCtx;
@@ -67,7 +68,7 @@
         }
         boolean reconciled = false;
         for (int i = 0; i < numBTrees; ++i) {
-            bTreeAccessors[i].search(rangeCursors[i], predicate);
+            btreeAccessors[i].search(rangeCursors[i], predicate);
             if (rangeCursors[i].hasNext()) {
                 rangeCursors[i].next();
                 // We use the predicate's to lock the key instead of the tuple that we get from cursor to avoid copying the tuple when we do the "unlatch dance"
@@ -83,14 +84,14 @@
                         return true;
                     }
                 }
-                if (i == 0 && includeMemComponent) {
+                if (i == 0 && includeMutableComponent) {
                     // unlatch/unpin
                     rangeCursors[i].reset();
                     searchCallback.reconcile(predicate.getLowKey());
                     reconciled = true;
 
                     // retraverse
-                    memBTreeAccessor.search(rangeCursors[i], predicate);
+                    btreeAccessors[0].search(rangeCursors[i], predicate);
                     searchCallback.complete(predicate.getLowKey());
                     if (rangeCursors[i].hasNext()) {
                         rangeCursors[i].next();
@@ -123,14 +124,14 @@
     @Override
     public void reset() throws HyracksDataException, IndexException {
         try {
-        if (rangeCursors != null) {
-            for (int i = 0; i < rangeCursors.length; ++i) {
-                rangeCursors[i].reset();
+            if (rangeCursors != null) {
+                for (int i = 0; i < rangeCursors.length; ++i) {
+                    rangeCursors[i].reset();
+                }
             }
-        }
-        rangeCursors = null;
-        nextHasBeenCalled = false;
-        foundTuple = false;
+            rangeCursors = null;
+            nextHasBeenCalled = false;
+            foundTuple = false;
         } finally {
             if (lsmHarness != null) {
                 lsmHarness.endSearch(opCtx);
@@ -141,41 +142,30 @@
     @Override
     public void open(ICursorInitialState initialState, ISearchPredicate searchPred) throws HyracksDataException {
         LSMBTreeCursorInitialState lsmInitialState = (LSMBTreeCursorInitialState) initialState;
-        includeMemComponent = lsmInitialState.getIncludeMemComponent();
+        operationalComponents = lsmInitialState.getOperationalComponents();
         lsmHarness = lsmInitialState.getLSMHarness();
         searchCallback = lsmInitialState.getSearchOperationCallback();
-        memBTreeAccessor = lsmInitialState.getMemBTreeAccessor();
         predicate = (RangePredicate) lsmInitialState.getSearchPredicate();
-
-        numBTrees = lsmInitialState.getNumBTrees();
+        numBTrees = operationalComponents.size();
         rangeCursors = new IIndexCursor[numBTrees];
-        int i = 0;
-        if (includeMemComponent) {
-            // No need for a bloom filter for the in-memory BTree.
-            IBTreeLeafFrame leafFrame = (IBTreeLeafFrame) lsmInitialState.getLeafFrameFactory().createFrame();
-            rangeCursors[i] = new BTreeRangeSearchCursor(leafFrame, false);
-            ++i;
-        }
-        for (; i < numBTrees; ++i) {
-            IBTreeLeafFrame leafFrame = (IBTreeLeafFrame) lsmInitialState.getLeafFrameFactory().createFrame();
-            rangeCursors[i] = new BloomFilterAwareBTreePointSearchCursor(leafFrame, false,
-                    ((LSMBTreeImmutableComponent) lsmInitialState.getOperationalComponents().get(i)).getBloomFilter());
-        }
+        btreeAccessors = new IIndexAccessor[numBTrees];
+        includeMutableComponent = false;
 
-        bTreeAccessors = new IIndexAccessor[numBTrees];
-        int cursorIx = 0;
-        ListIterator<ILSMComponent> btreesIter = lsmInitialState.getOperationalComponents().listIterator();
-        if (includeMemComponent) {
-            bTreeAccessors[cursorIx] = memBTreeAccessor;
-            ++cursorIx;
-            btreesIter.next();
-        }
-
-        while (btreesIter.hasNext()) {
-            BTree diskBTree = ((LSMBTreeImmutableComponent) btreesIter.next()).getBTree();
-            bTreeAccessors[cursorIx] = diskBTree.createAccessor(NoOpOperationCallback.INSTANCE,
-                    NoOpOperationCallback.INSTANCE);
-            cursorIx++;
+        for (int i = 0; i < numBTrees; i++) {
+            ILSMComponent component = operationalComponents.get(i);
+            BTree btree;
+            IBTreeLeafFrame leafFrame = (IBTreeLeafFrame) lsmInitialState.getLeafFrameFactory().createFrame();
+            if (component.getType() == LSMComponentType.MEMORY) {
+                includeMutableComponent = true;
+                // No need for a bloom filter for the in-memory BTree.
+                rangeCursors[i] = new BTreeRangeSearchCursor(leafFrame, false);
+                btree = (BTree) ((LSMBTreeMemoryComponent) component).getBTree();
+            } else {
+                rangeCursors[i] = new BloomFilterAwareBTreePointSearchCursor(leafFrame, false,
+                        ((LSMBTreeDiskComponent) component).getBloomFilter());
+                btree = (BTree) ((LSMBTreeDiskComponent) component).getBTree();
+            }
+            btreeAccessors[i] = btree.createAccessor(NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
         }
         nextHasBeenCalled = false;
         foundTuple = false;
diff --git a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeRangeSearchCursor.java b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeRangeSearchCursor.java
index 4bdebae..6eada4b 100644
--- a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeRangeSearchCursor.java
+++ b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeRangeSearchCursor.java
@@ -16,7 +16,6 @@
 package edu.uci.ics.hyracks.storage.am.lsm.btree.impls;
 
 import java.util.Iterator;
-import java.util.ListIterator;
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
@@ -35,6 +34,7 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent.LSMComponentType;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexOperationContext;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMIndexSearchCursor;
 
@@ -44,7 +44,7 @@
 
     private ISearchOperationCallback searchCallback;
     private RangePredicate predicate;
-    private IIndexAccessor memBTreeAccessor;
+    private IIndexAccessor[] btreeAccessors;
     private ArrayTupleBuilder tupleBuilder;
     private boolean proceed = true;
 
@@ -72,25 +72,25 @@
             if (!outputPriorityQueue.isEmpty()) {
                 PriorityQueueElement checkElement = outputPriorityQueue.peek();
                 if (proceed && !searchCallback.proceed(checkElement.getTuple())) {
-                    if (includeMemComponent) {
-                        PriorityQueueElement inMemElement = null;
-                        boolean inMemElementFound = false;
-                        // scan the PQ for the in-memory component's element
+                    if (includeMutableComponent) {
+                        PriorityQueueElement mutableElement = null;
+                        boolean mutableElementFound = false;
+                        // scan the PQ for the mutable component's element
                         Iterator<PriorityQueueElement> it = outputPriorityQueue.iterator();
                         while (it.hasNext()) {
-                            inMemElement = it.next();
-                            if (inMemElement.getCursorIndex() == 0) {
-                                inMemElementFound = true;
+                            mutableElement = it.next();
+                            if (mutableElement.getCursorIndex() == 0) {
+                                mutableElementFound = true;
                                 it.remove();
                                 break;
                             }
                         }
-                        if (inMemElementFound) {
+                        if (mutableElementFound) {
                             // copy the in-mem tuple
                             if (tupleBuilder == null) {
                                 tupleBuilder = new ArrayTupleBuilder(cmp.getKeyFieldCount());
                             }
-                            TupleUtils.copyTuple(tupleBuilder, inMemElement.getTuple(), cmp.getKeyFieldCount());
+                            TupleUtils.copyTuple(tupleBuilder, mutableElement.getTuple(), cmp.getKeyFieldCount());
                             copyTuple.reset(tupleBuilder.getFieldEndOffsets(), tupleBuilder.getByteArray());
 
                             // unlatch/unpin
@@ -105,11 +105,11 @@
                             }
                             // retraverse
                             reusablePred.setLowKey(copyTuple, true);
-                            memBTreeAccessor.search(rangeCursors[0], reusablePred);
-                            boolean isNotExhaustedCursor = pushIntoPriorityQueue(inMemElement);
-                            
+                            btreeAccessors[0].search(rangeCursors[0], reusablePred);
+                            boolean isNotExhaustedCursor = pushIntoPriorityQueue(mutableElement);
+
                             if (checkElement.getCursorIndex() == 0) {
-                                if (!isNotExhaustedCursor || cmp.compare(copyTuple, inMemElement.getTuple()) != 0) {
+                                if (!isNotExhaustedCursor || cmp.compare(copyTuple, mutableElement.getTuple()) != 0) {
                                     searchCallback.complete(copyTuple);
                                     searchCallback.cancel(copyTuple);
                                     continue;
@@ -117,7 +117,7 @@
                                 searchCallback.complete(copyTuple);
                             }
                         } else {
-                            // the in-memory cursor is exhausted
+                            // the mutable cursor is exhausted
                             searchCallback.reconcile(checkElement.getTuple());
                         }
                     } else {
@@ -174,46 +174,34 @@
             IndexException {
         LSMBTreeCursorInitialState lsmInitialState = (LSMBTreeCursorInitialState) initialState;
         cmp = lsmInitialState.getOriginalKeyComparator();
-        includeMemComponent = lsmInitialState.getIncludeMemComponent();
         operationalComponents = lsmInitialState.getOperationalComponents();
         lsmHarness = lsmInitialState.getLSMHarness();
         searchCallback = lsmInitialState.getSearchOperationCallback();
-        memBTreeAccessor = lsmInitialState.getMemBTreeAccessor();
         predicate = (RangePredicate) lsmInitialState.getSearchPredicate();
         reusablePred.setLowKeyComparator(cmp);
         reusablePred.setHighKey(predicate.getHighKey(), predicate.isHighKeyInclusive());
         reusablePred.setHighKeyComparator(predicate.getHighKeyComparator());
+        includeMutableComponent = false;
 
-        int numBTrees = lsmInitialState.getNumBTrees();
+        int numBTrees = operationalComponents.size();
         rangeCursors = new IIndexCursor[numBTrees];
+
+        btreeAccessors = new ITreeIndexAccessor[numBTrees];
         for (int i = 0; i < numBTrees; i++) {
+            ILSMComponent component = operationalComponents.get(i);
+            BTree btree;
             IBTreeLeafFrame leafFrame = (IBTreeLeafFrame) lsmInitialState.getLeafFrameFactory().createFrame();
             rangeCursors[i] = new BTreeRangeSearchCursor(leafFrame, false);
+            if (component.getType() == LSMComponentType.MEMORY) {
+                includeMutableComponent = true;
+                btree = (BTree) ((LSMBTreeMemoryComponent) component).getBTree();
+            } else {
+                btree = (BTree) ((LSMBTreeDiskComponent) component).getBTree();
+            }
+            btreeAccessors[i] = btree.createAccessor(NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
+            btreeAccessors[i].search(rangeCursors[i], searchPred);
         }
         setPriorityQueueComparator();
-
-        int cursorIx = 0;
-        ListIterator<ILSMComponent> btreesIter = operationalComponents.listIterator();
-        if (includeMemComponent) {
-            // Open cursor of in-memory BTree at index 0.
-            memBTreeAccessor.search(rangeCursors[cursorIx], searchPred);
-            // Skip 0 because it is the in-memory BTree.
-            ++cursorIx;
-            btreesIter.next();
-        }
-
-        // Open cursors of on-disk BTrees.
-        int numDiskComponents = includeMemComponent ? numBTrees - 1 : numBTrees;
-        ITreeIndexAccessor[] diskBTreeAccessors = new ITreeIndexAccessor[numDiskComponents];
-        int diskBTreeIx = 0;
-        while (btreesIter.hasNext()) {
-            BTree diskBTree = (BTree) ((LSMBTreeImmutableComponent) btreesIter.next()).getBTree();
-            diskBTreeAccessors[diskBTreeIx] = diskBTree.createAccessor(NoOpOperationCallback.INSTANCE,
-                    NoOpOperationCallback.INSTANCE);
-            diskBTreeAccessors[diskBTreeIx].search(rangeCursors[cursorIx], searchPred);
-            cursorIx++;
-            diskBTreeIx++;
-        }
         initPriorityQueue();
         proceed = true;
     }
diff --git a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeUtils.java b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeUtils.java
index 507ec02..8b363ff 100644
--- a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeUtils.java
+++ b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeUtils.java
@@ -15,6 +15,8 @@
 
 package edu.uci.ics.hyracks.storage.am.lsm.btree.util;
 
+import java.util.List;
+
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.api.io.FileReference;
@@ -31,7 +33,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.btree.impls.LSMBTreeFileManager;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.tuples.LSMBTreeCopyTupleWriterFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.tuples.LSMBTreeTupleWriterFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexFileManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
@@ -43,11 +45,11 @@
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
 
 public class LSMBTreeUtils {
-    public static LSMBTree createLSMTree(IVirtualBufferCache virtualBufferCache, FileReference file,
+    public static LSMBTree createLSMTree(List<IVirtualBufferCache> virtualBufferCaches, FileReference file,
             IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ITypeTraits[] typeTraits,
             IBinaryComparatorFactory[] cmpFactories, int[] bloomFilterKeyFields, double bloomFilterFalsePositiveRate,
             ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
+            ILSMIOOperationCallback ioOpCallback) {
         LSMBTreeTupleWriterFactory insertTupleWriterFactory = new LSMBTreeTupleWriterFactory(typeTraits,
                 cmpFactories.length, false);
         LSMBTreeTupleWriterFactory deleteTupleWriterFactory = new LSMBTreeTupleWriterFactory(typeTraits,
@@ -73,10 +75,10 @@
 
         ILSMIndexFileManager fileNameManager = new LSMBTreeFileManager(diskFileMapProvider, file, diskBTreeFactory);
 
-        LSMBTree lsmTree = new LSMBTree(virtualBufferCache, interiorFrameFactory, insertLeafFrameFactory,
+        LSMBTree lsmTree = new LSMBTree(virtualBufferCaches, interiorFrameFactory, insertLeafFrameFactory,
                 deleteLeafFrameFactory, fileNameManager, diskBTreeFactory, bulkLoadBTreeFactory, bloomFilterFactory,
                 bloomFilterFalsePositiveRate, diskFileMapProvider, typeTraits.length, cmpFactories, mergePolicy,
-                opTracker, ioScheduler, ioOpCallbackProvider);
+                opTracker, ioScheduler, ioOpCallback);
         return lsmTree;
     }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/pom.xml b/hyracks/hyracks-storage-am-lsm-common/pom.xml
index d52424b..4a6fe50 100644
--- a/hyracks/hyracks-storage-am-lsm-common/pom.xml
+++ b/hyracks/hyracks-storage-am-lsm-common/pom.xml
@@ -19,7 +19,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -39,21 +39,21 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-common</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-bloomfilter</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-btree</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>  	
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMComponent.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMComponent.java
index 72a3e1f..afbabe0 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMComponent.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMComponent.java
@@ -18,7 +18,27 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMOperationType;
 
 public interface ILSMComponent {
-    public boolean threadEnter(LSMOperationType opType) throws InterruptedException;
 
-    public void threadExit(LSMOperationType opType, boolean failedOperation) throws HyracksDataException;
+    enum LSMComponentType {
+        MEMORY,
+        DISK
+    }
+
+    enum ComponentState {
+        INACTIVE,
+        READABLE_WRITABLE,
+        READABLE_UNWRITABLE,
+        READABLE_UNWRITABLE_FLUSHING,
+        UNREADABLE_UNWRITABLE,
+        READABLE_MERGING
+    }
+
+    public boolean threadEnter(LSMOperationType opType, boolean isMutableComponent) throws HyracksDataException;
+
+    public void threadExit(LSMOperationType opType, boolean failedOperation, boolean isMutableComponent)
+            throws HyracksDataException;
+
+    public LSMComponentType getType();
+
+    public ComponentState getState();
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMHarness.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMHarness.java
index a006b97..bc7cbf7 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMHarness.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMHarness.java
@@ -29,8 +29,6 @@
     public boolean modify(ILSMIndexOperationContext ctx, boolean tryOperation, ITupleReference tuple)
             throws HyracksDataException, IndexException;
 
-    public void noOp(ILSMIndexOperationContext ctx) throws HyracksDataException;
-
     public void search(ILSMIndexOperationContext ctx, IIndexCursor cursor, ISearchPredicate pred)
             throws HyracksDataException, IndexException;
 
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperation.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperation.java
index c23dcea..2c3940f 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperation.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperation.java
@@ -15,17 +15,18 @@
 package edu.uci.ics.hyracks.storage.am.lsm.common.api;
 
 import java.util.Set;
+import java.util.concurrent.Callable;
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.io.IODeviceHandle;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 
-public interface ILSMIOOperation {
+public interface ILSMIOOperation extends Callable<Boolean> {
     public Set<IODeviceHandle> getReadDevices();
 
     public Set<IODeviceHandle> getWriteDevices();
 
-    public void perform() throws HyracksDataException, IndexException;
+    public Boolean call() throws HyracksDataException, IndexException;
 
     public ILSMIOOperationCallback getCallback();
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationCallback.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationCallback.java
index 7086b59..9af08fa 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationCallback.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationCallback.java
@@ -17,12 +17,36 @@
 import java.util.List;
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMOperationType;
 
 public interface ILSMIOOperationCallback {
-    public void beforeOperation() throws HyracksDataException;
 
-    public void afterOperation(List<ILSMComponent> oldComponents, ILSMComponent newComponent)
+    /**
+     * This method is called on an IO operation sometime before the operation is executed.
+     * (i.e. IO operations could be flush or merge operations.)
+     */
+    public void beforeOperation(LSMOperationType opType) throws HyracksDataException;
+
+    /**
+     * This method is called on an IO operation sometime after the operation was completed.
+     * (i.e. IO operations could be flush or merge operations.)
+     * 
+     * @param oldComponents
+     * @param newComponent
+     * @throws HyracksDataException
+     */
+    public void afterOperation(LSMOperationType opType, List<ILSMComponent> oldComponents, ILSMComponent newComponent)
             throws HyracksDataException;
 
-    public void afterFinalize(ILSMComponent newComponent) throws HyracksDataException;
+    /**
+     * This method is called on an IO operation when the operation needs any cleanup works
+     * regardless that the IO operation was executed or not. Once the IO operation is executed,
+     * this method should be called after ILSMIOOperationCallback.afterOperation() was called.
+     * 
+     * @param newComponent
+     * @throws HyracksDataException
+     */
+    public void afterFinalize(LSMOperationType opType, ILSMComponent newComponent) throws HyracksDataException;
+
+    public void setNumOfMutableComponents(int count);
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationCallbackFactory.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationCallbackFactory.java
index 6dbce32..804142e 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationCallbackFactory.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationCallbackFactory.java
@@ -17,5 +17,5 @@
 import java.io.Serializable;
 
 public interface ILSMIOOperationCallbackFactory extends Serializable {
-    public ILSMIOOperationCallback createIOOperationCallback(Object syncObj);
+    public ILSMIOOperationCallback createIOOperationCallback();
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndex.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndex.java
index 105b53a..d37a105 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndex.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndex.java
@@ -32,17 +32,17 @@
  * concurrent searches/updates/merges may be ongoing.
  */
 public interface ILSMIndex extends IIndex {
-    
+
     public void deactivate(boolean flushOnExit) throws HyracksDataException;
 
     public ILSMIndexAccessor createAccessor(IModificationOperationCallback modificationCallback,
-            ISearchOperationCallback searchCallback);
-
-    public boolean getFlushStatus();
+            ISearchOperationCallback searchCallback) throws HyracksDataException;
 
     public ILSMOperationTracker getOperationTracker();
 
     public ILSMIOOperationScheduler getIOScheduler();
+    
+    public ILSMIOOperationCallback getIOOperationCallback();
 
     public List<ILSMComponent> getImmutableComponents();
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexAccessor.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexAccessor.java
index cd60ded..3405b60 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexAccessor.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexAccessor.java
@@ -109,14 +109,4 @@
     public void forceInsert(ITupleReference tuple) throws HyracksDataException, IndexException;
 
     public void forceDelete(ITupleReference tuple) throws HyracksDataException, IndexException;
-
-    /**
-     * This method can be used to increase the number of 'active' operations of an index artificially,
-     * without actually modifying the index.
-     * This method does not block and is guaranteed to trigger the {@link ILSMOperationTracker}'s beforeOperation
-     * and afterOperation calls.
-     * 
-     * @throws HyracksDataException
-     */
-    public void noOp() throws HyracksDataException;
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexInternal.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexInternal.java
index c65c7cb..6020093 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexInternal.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexInternal.java
@@ -28,14 +28,14 @@
 
 public interface ILSMIndexInternal extends ILSMIndex {
     public ILSMIndexAccessorInternal createAccessor(IModificationOperationCallback modificationCallback,
-            ISearchOperationCallback searchCallback);
+            ISearchOperationCallback searchCallback) throws HyracksDataException;
 
     public void modify(IIndexOperationContext ictx, ITupleReference tuple) throws HyracksDataException, IndexException;
 
     public void search(ILSMIndexOperationContext ictx, IIndexCursor cursor, ISearchPredicate pred)
             throws HyracksDataException, IndexException;
 
-    public boolean scheduleFlush(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
+    public void scheduleFlush(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
             throws HyracksDataException;
 
     public ILSMComponent flush(ILSMIOOperation operation) throws HyracksDataException, IndexException;
@@ -43,13 +43,18 @@
     public void scheduleMerge(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
             throws HyracksDataException, IndexException;
 
-    public ILSMComponent merge(List<ILSMComponent> mergedComponents, ILSMIOOperation operation)
-            throws HyracksDataException, IndexException;
+    public ILSMComponent merge(ILSMIOOperation operation) throws HyracksDataException, IndexException;
 
     public void addComponent(ILSMComponent index);
 
     public void subsumeMergedComponents(ILSMComponent newComponent, List<ILSMComponent> mergedComponents);
 
+    public void changeMutableComponent();
+
+    public void changeFlushStatusForCurrentMutableCompoent(boolean needsFlush);
+
+    public boolean hasFlushRequestForCurrentMutableComponent();
+
     /**
      * Populates the context's component holder with a snapshot of the components involved in the operation.
      * 
@@ -58,12 +63,6 @@
      */
     public void getOperationalComponents(ILSMIndexOperationContext ctx);
 
-    public List<ILSMComponent> getImmutableComponents();
-
     public void markAsValid(ILSMComponent lsmComponent) throws HyracksDataException;
 
-    public void setFlushStatus(boolean needsFlush);
-
-    public boolean isFull();
-
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexOperationContext.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexOperationContext.java
index bbd2ca8..fcd4037 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexOperationContext.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexOperationContext.java
@@ -26,4 +26,6 @@
     public ISearchOperationCallback getSearchOperationCallback();
 
     public IModificationOperationCallback getModificationCallback();
+
+    public void setCurrentMutableComponentId(int currentMutableComponentId);
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMMergePolicy.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMMergePolicy.java
index 5eaa6f6..1473071 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMMergePolicy.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMMergePolicy.java
@@ -19,5 +19,5 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 
 public interface ILSMMergePolicy {
-    public void diskComponentAdded(ILSMIndex index, int totalNumDiskComponents) throws HyracksDataException, IndexException;
+    public void diskComponentAdded(ILSMIndex index) throws HyracksDataException, IndexException;
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/IVirtualBufferCacheProvider.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/IVirtualBufferCacheProvider.java
index cd75df0..eff390f 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/IVirtualBufferCacheProvider.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/IVirtualBufferCacheProvider.java
@@ -15,9 +15,10 @@
 package edu.uci.ics.hyracks.storage.am.lsm.common.api;
 
 import java.io.Serializable;
+import java.util.List;
 
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 
 public interface IVirtualBufferCacheProvider extends Serializable {
-    public IVirtualBufferCache getVirtualBufferCache(IHyracksTaskContext ctx);
+    public List<IVirtualBufferCache> getVirtualBufferCaches(IHyracksTaskContext ctx);
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelper.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelper.java
index e79a394..e277edc 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelper.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelper.java
@@ -15,10 +15,12 @@
 
 package edu.uci.ics.hyracks.storage.am.lsm.common.dataflow;
 
+import java.util.List;
+
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IndexDataflowHelper;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
@@ -30,30 +32,30 @@
 
     protected final double bloomFilterFalsePositiveRate;
 
-    protected final IVirtualBufferCache virtualBufferCache;
+    protected final List<IVirtualBufferCache> virtualBufferCaches;
     protected final ILSMMergePolicy mergePolicy;
     protected final ILSMIOOperationScheduler ioScheduler;
     protected final ILSMOperationTrackerProvider opTrackerFactory;
-    protected final ILSMIOOperationCallbackProvider ioOpCallbackProvider;
+    protected final ILSMIOOperationCallbackFactory ioOpCallbackFactory;
 
     public AbstractLSMIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            IVirtualBufferCache virtualBufferCache, ILSMMergePolicy mergePolicy,
+            List<IVirtualBufferCache> virtualBufferCaches, ILSMMergePolicy mergePolicy,
             ILSMOperationTrackerProvider opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        this(opDesc, ctx, partition, virtualBufferCache, DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE, mergePolicy,
-                opTrackerFactory, ioScheduler, ioOpCallbackProvider);
+            ILSMIOOperationCallbackFactory ioOpCallbackFactory) {
+        this(opDesc, ctx, partition, virtualBufferCaches, DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE, mergePolicy,
+                opTrackerFactory, ioScheduler, ioOpCallbackFactory);
     }
 
     public AbstractLSMIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            IVirtualBufferCache virtualBufferCache, double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy,
-            ILSMOperationTrackerProvider opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
+            List<IVirtualBufferCache> virtualBufferCaches, double bloomFilterFalsePositiveRate,
+            ILSMMergePolicy mergePolicy, ILSMOperationTrackerProvider opTrackerFactory,
+            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackFactory ioOpCallbackFactory) {
         super(opDesc, ctx, partition);
-        this.virtualBufferCache = virtualBufferCache;
+        this.virtualBufferCaches = virtualBufferCaches;
         this.bloomFilterFalsePositiveRate = bloomFilterFalsePositiveRate;
         this.mergePolicy = mergePolicy;
         this.opTrackerFactory = opTrackerFactory;
         this.ioScheduler = ioScheduler;
-        this.ioOpCallbackProvider = ioOpCallbackProvider;
+        this.ioOpCallbackFactory = ioOpCallbackFactory;
     }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelperFactory.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelperFactory.java
index 205bf27..2c082bb 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelperFactory.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelperFactory.java
@@ -16,7 +16,7 @@
 package edu.uci.ics.hyracks.storage.am.lsm.common.dataflow;
 
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexDataflowHelperFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
@@ -29,18 +29,18 @@
     protected final ILSMMergePolicyProvider mergePolicyProvider;
     protected final ILSMOperationTrackerProvider opTrackerFactory;
     protected final ILSMIOOperationSchedulerProvider ioSchedulerProvider;
-    protected final ILSMIOOperationCallbackProvider ioOpCallbackProvider;
+    protected final ILSMIOOperationCallbackFactory ioOpCallbackFactory;
     protected final double bloomFilterFalsePositiveRate;
 
     public AbstractLSMIndexDataflowHelperFactory(IVirtualBufferCacheProvider virtualBufferCacheProvider,
             ILSMMergePolicyProvider mergePolicyProvider, ILSMOperationTrackerProvider opTrackerFactory,
-            ILSMIOOperationSchedulerProvider ioSchedulerProvider, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
+            ILSMIOOperationSchedulerProvider ioSchedulerProvider, ILSMIOOperationCallbackFactory ioOpCallbackFactory,
             double bloomFilterFalsePositiveRate) {
         this.virtualBufferCacheProvider = virtualBufferCacheProvider;
         this.mergePolicyProvider = mergePolicyProvider;
         this.opTrackerFactory = opTrackerFactory;
         this.ioSchedulerProvider = ioSchedulerProvider;
-        this.ioOpCallbackProvider = ioOpCallbackProvider;
+        this.ioOpCallbackFactory = ioOpCallbackFactory;
         this.bloomFilterFalsePositiveRate = bloomFilterFalsePositiveRate;
     }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMIndexInsertUpdateDeleteOperatorNodePushable.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMIndexInsertUpdateDeleteOperatorNodePushable.java
index 4c69634..5bf52e4 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMIndexInsertUpdateDeleteOperatorNodePushable.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMIndexInsertUpdateDeleteOperatorNodePushable.java
@@ -46,7 +46,6 @@
                 if (tupleFilter != null) {
                     frameTuple.reset(accessor, i);
                     if (!tupleFilter.accept(frameTuple)) {
-                        lsmAccessor.noOp();
                         continue;
                     }
                 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractDiskLSMComponent.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractDiskLSMComponent.java
new file mode 100644
index 0000000..bc6baeb
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractDiskLSMComponent.java
@@ -0,0 +1,88 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+
+public abstract class AbstractDiskLSMComponent extends AbstractLSMComponent {
+
+    public AbstractDiskLSMComponent() {
+        super();
+        state = ComponentState.READABLE_UNWRITABLE;
+    }
+
+    @Override
+    public boolean threadEnter(LSMOperationType opType, boolean isMutableComponent) {
+        assert state != ComponentState.INACTIVE;
+
+        switch (opType) {
+            case FORCE_MODIFICATION:
+            case MODIFICATION:
+            case SEARCH:
+                readerCount++;
+                break;
+            case MERGE:
+                if (state == ComponentState.READABLE_MERGING) {
+                    // This should never happen unless there are two concurrent merges that were scheduled 
+                    // concurrently and they have interleaving components to be merged. 
+                    // This should be handled properly by the merge policy, but we guard against that here anyway.
+                    return false;
+                }
+                state = ComponentState.READABLE_MERGING;
+                readerCount++;
+                break;
+            default:
+                throw new UnsupportedOperationException("Unsupported operation " + opType);
+        }
+        return true;
+    }
+
+    @Override
+    public void threadExit(LSMOperationType opType, boolean failedOperation, boolean isMutableComponent)
+            throws HyracksDataException {
+        switch (opType) {
+            case MERGE:
+                // In case two merge operations were scheduled to merge an overlapping set of components, the second merge will fail and it must
+                // reset those components back to their previous state.
+                if (failedOperation) {
+                    state = ComponentState.READABLE_UNWRITABLE;
+                }
+            case FORCE_MODIFICATION:
+            case MODIFICATION:
+            case SEARCH:
+                readerCount--;
+                if (readerCount == 0 && state == ComponentState.READABLE_MERGING) {
+                    state = ComponentState.INACTIVE;
+                }
+                break;
+            default:
+                throw new UnsupportedOperationException("Unsupported operation " + opType);
+        }
+        assert readerCount > -1;
+    }
+
+    @Override
+    public LSMComponentType getType() {
+        return LSMComponentType.DISK;
+    }
+
+    @Override
+    public ComponentState getState() {
+        return state;
+    }
+
+    protected abstract void destroy() throws HyracksDataException;
+
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractImmutableLSMComponent.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractImmutableLSMComponent.java
deleted file mode 100644
index 376c2e4..0000000
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractImmutableLSMComponent.java
+++ /dev/null
@@ -1,85 +0,0 @@
-/*
- * Copyright 2009-2013 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
-
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
-
-public abstract class AbstractImmutableLSMComponent implements ILSMComponent {
-
-    private ComponentState state;
-    private int readerCount;
-
-    private enum ComponentState {
-        READABLE,
-        READABLE_MERGING,
-        KILLED
-    }
-
-    public AbstractImmutableLSMComponent() {
-        state = ComponentState.READABLE;
-        readerCount = 0;
-    }
-
-    @Override
-    public synchronized boolean threadEnter(LSMOperationType opType) {
-        if (state == ComponentState.KILLED) {
-            return false;
-        }
-
-        switch (opType) {
-            case FORCE_MODIFICATION:
-            case MODIFICATION:
-            case SEARCH:
-                readerCount++;
-                break;
-            case MERGE:
-                if (state == ComponentState.READABLE_MERGING) {
-                    return false;
-                }
-                state = ComponentState.READABLE_MERGING;
-                readerCount++;
-                break;
-            default:
-                throw new UnsupportedOperationException("Unsupported operation " + opType);
-        }
-        return true;
-    }
-
-    @Override
-    public synchronized void threadExit(LSMOperationType opType, boolean failedOperation) throws HyracksDataException {
-        switch (opType) {
-            case MERGE:
-                if (failedOperation) {
-                    state = ComponentState.READABLE;
-                }
-            case FORCE_MODIFICATION:
-            case MODIFICATION:
-            case SEARCH:
-                readerCount--;
-
-                if (readerCount == 0 && state == ComponentState.READABLE_MERGING) {
-                    destroy();
-                    state = ComponentState.KILLED;
-                }
-                break;
-            default:
-                throw new UnsupportedOperationException("Unsupported operation " + opType);
-        }
-    }
-
-    protected abstract void destroy() throws HyracksDataException;
-
-}
diff --git a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractLSMComponent.java
similarity index 61%
copy from hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
copy to hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractLSMComponent.java
index cde5022..5dab25f 100644
--- a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractLSMComponent.java
@@ -12,17 +12,21 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
 
-package edu.uci.ics.hyracks.storage.am.btree.exceptions;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
 
-public class BTreeDuplicateKeyException extends BTreeException {
-    private static final long serialVersionUID = 1L;
+public abstract class AbstractLSMComponent implements ILSMComponent {
 
-    public BTreeDuplicateKeyException(Exception e) {
-        super(e);
+    protected ComponentState state;
+    protected int readerCount;
+
+    public AbstractLSMComponent() {
+        readerCount = 0;
     }
 
-    public BTreeDuplicateKeyException(String message) {
-        super(message);
+    @Override
+    public ComponentState getState() {
+        return state;
     }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractLSMIndex.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractLSMIndex.java
index d9da9e5..44bcfc2 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractLSMIndex.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractLSMIndex.java
@@ -18,13 +18,15 @@
 import java.util.ArrayList;
 import java.util.LinkedList;
 import java.util.List;
-import java.util.concurrent.atomic.AtomicReference;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrame;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMHarness;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexFileManager;
@@ -41,37 +43,45 @@
     protected final ILSMHarness lsmHarness;
 
     protected final ILSMIOOperationScheduler ioScheduler;
-    protected final ILSMIOOperationCallbackProvider ioOpCallbackProvider;
+    protected final ILSMIOOperationCallback ioOpCallback;
 
     // In-memory components.   
-    protected final IVirtualBufferCache virtualBufferCache;
+    protected final List<ILSMComponent> memoryComponents;
+    protected final List<IVirtualBufferCache> virtualBufferCaches;
+    protected AtomicInteger currentMutableComponentId;
 
     // On-disk components.    
     protected final IBufferCache diskBufferCache;
     protected final ILSMIndexFileManager fileManager;
     protected final IFileMapProvider diskFileMapProvider;
-    protected final AtomicReference<List<ILSMComponent>> componentsRef;
+    protected final List<ILSMComponent> diskComponents;
     protected final double bloomFilterFalsePositiveRate;
 
     protected boolean isActivated;
 
-    private boolean needsFlush = false;
+    protected final AtomicBoolean[] flushRequests;
 
-    public AbstractLSMIndex(IVirtualBufferCache virtualBufferCache, IBufferCache diskBufferCache,
+    public AbstractLSMIndex(List<IVirtualBufferCache> virtualBufferCaches, IBufferCache diskBufferCache,
             ILSMIndexFileManager fileManager, IFileMapProvider diskFileMapProvider,
             double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        this.virtualBufferCache = virtualBufferCache;
+            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallback ioOpCallback) {
+        this.virtualBufferCaches = virtualBufferCaches;
         this.diskBufferCache = diskBufferCache;
         this.diskFileMapProvider = diskFileMapProvider;
         this.fileManager = fileManager;
         this.bloomFilterFalsePositiveRate = bloomFilterFalsePositiveRate;
         this.ioScheduler = ioScheduler;
-        this.ioOpCallbackProvider = ioOpCallbackProvider;
+        this.ioOpCallback = ioOpCallback;
+        this.ioOpCallback.setNumOfMutableComponents(virtualBufferCaches.size());
         lsmHarness = new LSMHarness(this, mergePolicy, opTracker);
         isActivated = false;
-        componentsRef = new AtomicReference<List<ILSMComponent>>();
-        componentsRef.set(new LinkedList<ILSMComponent>());
+        diskComponents = new LinkedList<ILSMComponent>();
+        memoryComponents = new ArrayList<ILSMComponent>();
+        currentMutableComponentId = new AtomicInteger();
+        flushRequests = new AtomicBoolean[virtualBufferCaches.size()];
+        for (int i = 0; i < virtualBufferCaches.size(); i++) {
+            flushRequests[i] = new AtomicBoolean();
+        }
     }
 
     protected void forceFlushDirtyPages(ITreeIndex treeIndex) throws HyracksDataException {
@@ -129,44 +139,35 @@
 
     @Override
     public void addComponent(ILSMComponent c) {
-        List<ILSMComponent> oldList = componentsRef.get();
-        List<ILSMComponent> newList = new ArrayList<ILSMComponent>();
-        newList.add(c);
-        for (ILSMComponent oc : oldList) {
-            newList.add(oc);
-        }
-        componentsRef.set(newList);
+        diskComponents.add(0, c);
     }
 
     @Override
     public void subsumeMergedComponents(ILSMComponent newComponent, List<ILSMComponent> mergedComponents) {
-        List<ILSMComponent> oldList = componentsRef.get();
-        List<ILSMComponent> newList = new ArrayList<ILSMComponent>();
-        int swapIndex = oldList.indexOf(mergedComponents.get(0));
-        int swapSize = mergedComponents.size();
-        for (int i = 0; i < oldList.size(); i++) {
-            if (i < swapIndex || i >= swapIndex + swapSize) {
-                newList.add(oldList.get(i));
-            } else if (i == swapIndex) {
-                newList.add(newComponent);
-            }
-        }
-        componentsRef.set(newList);
+        int swapIndex = diskComponents.indexOf(mergedComponents.get(0));
+        diskComponents.removeAll(mergedComponents);
+        diskComponents.add(swapIndex, newComponent);
+    }
+
+    @Override
+    public void changeMutableComponent() {
+        currentMutableComponentId.set((currentMutableComponentId.get() + 1) % memoryComponents.size());
+        ((AbstractMemoryLSMComponent) memoryComponents.get(currentMutableComponentId.get())).setActive();
     }
 
     @Override
     public List<ILSMComponent> getImmutableComponents() {
-        return componentsRef.get();
+        return diskComponents;
     }
 
     @Override
-    public void setFlushStatus(boolean needsFlush) {
-        this.needsFlush = needsFlush;
+    public void changeFlushStatusForCurrentMutableCompoent(boolean needsFlush) {
+        flushRequests[currentMutableComponentId.get()].set(needsFlush);
     }
 
     @Override
-    public boolean getFlushStatus() {
-        return needsFlush;
+    public boolean hasFlushRequestForCurrentMutableComponent() {
+        return flushRequests[currentMutableComponentId.get()].get();
     }
 
     @Override
@@ -180,8 +181,8 @@
     }
 
     @Override
-    public boolean isFull() {
-        return virtualBufferCache.isFull();
+    public ILSMIOOperationCallback getIOOperationCallback() {
+        return ioOpCallback;
     }
 
     @Override
@@ -189,6 +190,18 @@
         return diskBufferCache;
     }
 
+    public boolean isEmptyIndex() throws HyracksDataException {
+        boolean isModified = false;
+        for (ILSMComponent c : memoryComponents) {
+            AbstractMemoryLSMComponent mutableComponent = (AbstractMemoryLSMComponent) c;
+            if (mutableComponent.isModified()) {
+                isModified = true;
+                break;
+            }
+        }
+        return diskComponents.isEmpty() && !isModified;
+    }
+
     @Override
     public String toString() {
         return "LSMIndex [" + fileManager.getBaseDir() + "]";
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractMemoryLSMComponent.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractMemoryLSMComponent.java
new file mode 100644
index 0000000..ce4817b
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractMemoryLSMComponent.java
@@ -0,0 +1,178 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
+
+public abstract class AbstractMemoryLSMComponent extends AbstractLSMComponent {
+
+    private int writerCount;
+    private final IVirtualBufferCache vbc;
+    private final AtomicBoolean isModified;
+    private boolean requestedToBeActive;
+
+    public AbstractMemoryLSMComponent(IVirtualBufferCache vbc, boolean isActive) {
+        super();
+        this.vbc = vbc;
+        writerCount = 0;
+        if (isActive) {
+            state = ComponentState.READABLE_WRITABLE;
+        } else {
+            state = ComponentState.INACTIVE;
+        }
+        isModified = new AtomicBoolean();
+    }
+
+    @Override
+    public boolean threadEnter(LSMOperationType opType, boolean isMutableComponent) throws HyracksDataException {
+        if (state == ComponentState.INACTIVE && requestedToBeActive) {
+            state = ComponentState.READABLE_WRITABLE;
+            requestedToBeActive = false;
+        }
+        switch (opType) {
+            case FORCE_MODIFICATION:
+                if (isMutableComponent) {
+                    if (state == ComponentState.READABLE_WRITABLE || state == ComponentState.READABLE_UNWRITABLE) {
+                        writerCount++;
+                    } else {
+                        return false;
+                    }
+                } else {
+                    if (state == ComponentState.READABLE_UNWRITABLE
+                            || state == ComponentState.READABLE_UNWRITABLE_FLUSHING) {
+                        readerCount++;
+                    } else {
+                        return false;
+                    }
+                }
+                break;
+            case MODIFICATION:
+                if (isMutableComponent) {
+                    if (state == ComponentState.READABLE_WRITABLE) {
+                        writerCount++;
+                    } else {
+                        return false;
+                    }
+                } else {
+                    if (state == ComponentState.READABLE_UNWRITABLE
+                            || state == ComponentState.READABLE_UNWRITABLE_FLUSHING) {
+                        readerCount++;
+                    } else {
+                        return false;
+                    }
+                }
+                break;
+            case SEARCH:
+                if (state == ComponentState.READABLE_WRITABLE || state == ComponentState.READABLE_UNWRITABLE
+                        || state == ComponentState.READABLE_UNWRITABLE_FLUSHING) {
+                    readerCount++;
+                } else {
+                    return false;
+                }
+                break;
+            case FLUSH:
+                if (state == ComponentState.READABLE_WRITABLE || state == ComponentState.READABLE_UNWRITABLE) {
+                    assert writerCount == 0;
+                    state = ComponentState.READABLE_UNWRITABLE_FLUSHING;
+                    readerCount++;
+                } else {
+                    return false;
+                }
+                break;
+            default:
+                throw new UnsupportedOperationException("Unsupported operation " + opType);
+        }
+        return true;
+    }
+
+    @Override
+    public void threadExit(LSMOperationType opType, boolean failedOperation, boolean isMutableComponent)
+            throws HyracksDataException {
+        switch (opType) {
+            case FORCE_MODIFICATION:
+            case MODIFICATION:
+                if (isMutableComponent) {
+                    writerCount--;
+                    if (state == ComponentState.READABLE_WRITABLE && isFull()) {
+                        state = ComponentState.READABLE_UNWRITABLE;
+                    }
+                } else {
+                    readerCount--;
+                    if (state == ComponentState.UNREADABLE_UNWRITABLE && readerCount == 0) {
+                        state = ComponentState.INACTIVE;
+                    }
+                }
+                break;
+            case SEARCH:
+                readerCount--;
+                if (state == ComponentState.UNREADABLE_UNWRITABLE && readerCount == 0) {
+                    state = ComponentState.INACTIVE;
+                }
+                break;
+            case FLUSH:
+                assert state == ComponentState.READABLE_UNWRITABLE_FLUSHING;
+                readerCount--;
+                if (readerCount == 0) {
+                    state = ComponentState.INACTIVE;
+                } else {
+                    state = ComponentState.UNREADABLE_UNWRITABLE;
+                }
+                break;
+            default:
+                throw new UnsupportedOperationException("Unsupported operation " + opType);
+        }
+        assert readerCount > -1 && writerCount > -1;
+    }
+
+    public boolean isReadable() {
+        if (state == ComponentState.INACTIVE || state == ComponentState.UNREADABLE_UNWRITABLE) {
+            return false;
+        }
+        return true;
+    }
+
+    @Override
+    public LSMComponentType getType() {
+        return LSMComponentType.MEMORY;
+    }
+
+    @Override
+    public ComponentState getState() {
+        return state;
+    }
+
+    public void setActive() {
+        requestedToBeActive = true;
+    }
+
+    public void setIsModified() {
+        isModified.set(true);
+    }
+
+    public boolean isModified() {
+        return isModified.get();
+    }
+
+    public boolean isFull() {
+        return vbc.isFull();
+    }
+
+    protected void reset() throws HyracksDataException {
+        isModified.set(false);
+    }
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractMutableLSMComponent.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractMutableLSMComponent.java
deleted file mode 100644
index 6ca6581..0000000
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractMutableLSMComponent.java
+++ /dev/null
@@ -1,131 +0,0 @@
-/*
- * Copyright 2009-2013 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
-
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
-
-public abstract class AbstractMutableLSMComponent implements ILSMComponent {
-
-    private int readerCount;
-    private int writerCount;
-    private ComponentState state;
-
-    private boolean isModified;
-
-    private enum ComponentState {
-        READABLE_WRITABLE,
-        READABLE_UNWRITABLE,
-        READABLE_UNWRITABLE_FLUSHING,
-        UNREADABLE_UNWRITABLE
-    }
-
-    public AbstractMutableLSMComponent() {
-        readerCount = 0;
-        writerCount = 0;
-        state = ComponentState.READABLE_WRITABLE;
-        isModified = false;
-    }
-
-    @Override
-    public synchronized boolean threadEnter(LSMOperationType opType) throws InterruptedException {
-        switch (opType) {
-            case FORCE_MODIFICATION:
-                if (state != ComponentState.READABLE_WRITABLE && state != ComponentState.READABLE_UNWRITABLE) {
-                    return false;
-                }
-                writerCount++;
-                break;
-            case MODIFICATION:
-                if (state != ComponentState.READABLE_WRITABLE) {
-                    return false;
-                }
-                writerCount++;
-                break;
-            case SEARCH:
-                if (state == ComponentState.UNREADABLE_UNWRITABLE) {
-                    return false;
-                }
-                readerCount++;
-                break;
-            case FLUSH:
-                if (state == ComponentState.READABLE_UNWRITABLE_FLUSHING
-                        || state == ComponentState.UNREADABLE_UNWRITABLE) {
-                    return false;
-                }
-
-                state = ComponentState.READABLE_UNWRITABLE_FLUSHING;
-                while (writerCount > 0) {
-                    wait();
-                }
-                readerCount++;
-                break;
-            default:
-                throw new UnsupportedOperationException("Unsupported operation " + opType);
-        }
-        return true;
-    }
-
-    @Override
-    public synchronized void threadExit(LSMOperationType opType, boolean failedOperation) throws HyracksDataException {
-        switch (opType) {
-            case FORCE_MODIFICATION:
-            case MODIFICATION:
-                writerCount--;
-                if (state == ComponentState.READABLE_WRITABLE && isFull()) {
-                    state = ComponentState.READABLE_UNWRITABLE;
-                }
-                break;
-            case SEARCH:
-                readerCount--;
-                if (state == ComponentState.UNREADABLE_UNWRITABLE && readerCount == 0) {
-                    reset();
-                    state = ComponentState.READABLE_WRITABLE;
-                } else if (state == ComponentState.READABLE_WRITABLE && isFull()) {
-                    state = ComponentState.READABLE_UNWRITABLE;
-                }
-                break;
-            case FLUSH:
-                if (failedOperation) {
-                    state = isFull() ? ComponentState.READABLE_UNWRITABLE : ComponentState.READABLE_WRITABLE;
-                }
-                readerCount--;
-                if (readerCount == 0) {
-                    reset();
-                    state = ComponentState.READABLE_WRITABLE;
-                } else if (state == ComponentState.READABLE_UNWRITABLE_FLUSHING) {
-                    state = ComponentState.UNREADABLE_UNWRITABLE;
-                }
-                break;
-            default:
-                throw new UnsupportedOperationException("Unsupported operation " + opType);
-        }
-        notifyAll();
-    }
-
-    public void setIsModified() {
-        isModified = true;
-    }
-
-    public boolean isModified() {
-        return isModified;
-    }
-
-    protected abstract boolean isFull();
-
-    protected void reset() throws HyracksDataException {
-        isModified = false;
-    }
-}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AsynchronousScheduler.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AsynchronousScheduler.java
new file mode 100644
index 0000000..25894f1
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AsynchronousScheduler.java
@@ -0,0 +1,37 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ThreadFactory;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperation;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
+
+public class AsynchronousScheduler implements ILSMIOOperationScheduler {
+    public final static AsynchronousScheduler INSTANCE = new AsynchronousScheduler();
+    private ExecutorService executor;
+
+    public void init(ThreadFactory threadFactory) {
+        executor = Executors.newCachedThreadPool(threadFactory);
+    }
+
+    @Override
+    public void scheduleOperation(ILSMIOOperation operation) throws HyracksDataException {
+        executor.submit(operation);
+    }
+}
\ No newline at end of file
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/BlockingIOOperationCallbackWrapper.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/BlockingIOOperationCallbackWrapper.java
index 2510311..fefe812 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/BlockingIOOperationCallbackWrapper.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/BlockingIOOperationCallbackWrapper.java
@@ -32,26 +32,31 @@
 
     public synchronized void waitForIO() throws InterruptedException {
         if (!notified) {
-            this.wait();
+            wait();
         }
         notified = false;
     }
 
     @Override
-    public void beforeOperation() throws HyracksDataException {
-        wrappedCallback.beforeOperation();
+    public void beforeOperation(LSMOperationType opType) throws HyracksDataException {
+        wrappedCallback.beforeOperation(opType);
     }
 
     @Override
-    public void afterOperation(List<ILSMComponent> oldComponents, ILSMComponent newComponent)
+    public void afterOperation(LSMOperationType opType, List<ILSMComponent> oldComponents, ILSMComponent newComponent)
             throws HyracksDataException {
-        wrappedCallback.afterOperation(oldComponents, newComponent);
+        wrappedCallback.afterOperation(opType, oldComponents, newComponent);
     }
 
     @Override
-    public synchronized void afterFinalize(ILSMComponent newComponent) throws HyracksDataException {
-        wrappedCallback.afterFinalize(newComponent);
-        this.notifyAll();
+    public synchronized void afterFinalize(LSMOperationType opType, ILSMComponent newComponent) throws HyracksDataException {
+        wrappedCallback.afterFinalize(opType, newComponent);
+        notifyAll();
         notified = true;
     }
+
+    @Override
+    public void setNumOfMutableComponents(int count) {
+        wrappedCallback.setNumOfMutableComponents(count);
+    }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ConstantMergePolicy.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ConstantMergePolicy.java
index 0ecfeb5..b6f5657 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ConstantMergePolicy.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ConstantMergePolicy.java
@@ -31,9 +31,8 @@
     }
 
     @Override
-    public void diskComponentAdded(final ILSMIndex index, int totalNumDiskComponents) throws HyracksDataException,
-            IndexException {
-        if (totalNumDiskComponents >= threshold) {
+    public void diskComponentAdded(final ILSMIndex index) throws HyracksDataException, IndexException {
+        if (index.getImmutableComponents().size() >= threshold) {
             ILSMIndexAccessor accessor = (ILSMIndexAccessor) index.createAccessor(NoOpOperationCallback.INSTANCE,
                     NoOpOperationCallback.INSTANCE);
             accessor.scheduleMerge(NoOpIOOperationCallback.INSTANCE);
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMHarness.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMHarness.java
index 1632725..ca775b7 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMHarness.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMHarness.java
@@ -15,7 +15,6 @@
 
 package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
 
-import java.util.ArrayList;
 import java.util.List;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -27,6 +26,7 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent.LSMComponentType;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMHarness;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperation;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
@@ -48,63 +48,154 @@
         this.mergePolicy = mergePolicy;
     }
 
-    private void threadExit(ILSMIndexOperationContext opCtx, LSMOperationType opType) throws HyracksDataException {
-        if (!lsmIndex.getFlushStatus() && lsmIndex.isFull()) {
-            lsmIndex.setFlushStatus(true);
-        }
-        opTracker.afterOperation(lsmIndex, opType, opCtx.getSearchOperationCallback(), opCtx.getModificationCallback());
-    }
-
-    private boolean getAndEnterComponents(ILSMIndexOperationContext ctx, LSMOperationType opType, boolean tryOperation)
+    private boolean getAndEnterComponents(ILSMIndexOperationContext ctx, LSMOperationType opType, boolean isTryOperation)
             throws HyracksDataException {
-        int numEntered = 0;
-        boolean entranceSuccessful = false;
-        List<ILSMComponent> entered = new ArrayList<ILSMComponent>();
-
-        while (!entranceSuccessful) {
-            entered.clear();
-            lsmIndex.getOperationalComponents(ctx);
-            List<ILSMComponent> components = ctx.getComponentHolder();
-            try {
-                for (ILSMComponent c : components) {
-                    if (!c.threadEnter(opType)) {
-                        break;
-                    }
-                    numEntered++;
-                    entered.add(c);
-                }
-                entranceSuccessful = numEntered == components.size();
-            } catch (InterruptedException e) {
-                entranceSuccessful = false;
-                throw new HyracksDataException(e);
-            } finally {
-                if (!entranceSuccessful) {
-                    for (ILSMComponent c : components) {
-                        if (numEntered <= 0) {
-                            break;
+        synchronized (opTracker) {
+            while (true) {
+                lsmIndex.getOperationalComponents(ctx);
+                // Before entering the components, prune those corner cases that indeed should not proceed.
+                switch (opType) {
+                    case FLUSH:
+                        ILSMComponent flushingComponent = ctx.getComponentHolder().get(0);
+                        if (!((AbstractMemoryLSMComponent) flushingComponent).isModified()) {
+                            // The mutable component has not been modified by any writer. There is nothing to flush.
+                            return false;
                         }
-                        c.threadExit(opType, true);
-                        numEntered--;
-                    }
+                        break;
+                    case MERGE:
+                        if (ctx.getComponentHolder().size() < 2) {
+                            // There is only a single component. There is nothing to merge.
+                            return false;
+                        }
+                    default:
+                        break;
+                }
+                if (enterComponents(ctx, opType)) {
+                    return true;
+                } else if (isTryOperation) {
+                    return false;
+                }
+                try {
+                    // Flush and merge operations should never reach this wait call, because they are always try operations.
+                    // If they fail to enter the components, then it means that there are an ongoing flush/merge operation on 
+                    // the same components, so they should not proceed.
+                    opTracker.wait();
+                } catch (InterruptedException e) {
+                    throw new HyracksDataException(e);
                 }
             }
-            if (tryOperation && !entranceSuccessful) {
+        }
+    }
+
+    private boolean enterComponents(ILSMIndexOperationContext ctx, LSMOperationType opType) throws HyracksDataException {
+        List<ILSMComponent> components = ctx.getComponentHolder();
+        int numEntered = 0;
+        boolean entranceSuccessful = false;
+        try {
+            for (ILSMComponent c : components) {
+                boolean isMutableComponent = numEntered == 0 && c.getType() == LSMComponentType.MEMORY ? true : false;
+                if (!c.threadEnter(opType, isMutableComponent)) {
+                    break;
+                }
+                numEntered++;
+            }
+            entranceSuccessful = numEntered == components.size();
+        } finally {
+            if (!entranceSuccessful) {
+                int i = 0;
+                for (ILSMComponent c : components) {
+                    if (numEntered == 0) {
+                        break;
+                    }
+                    boolean isMutableComponent = i == 0 && c.getType() == LSMComponentType.MEMORY ? true : false;
+                    c.threadExit(opType, true, isMutableComponent);
+                    i++;
+                    numEntered--;
+                }
                 return false;
             }
         }
-
+        // Check if there is any action that is needed to be taken based on the operation type
+        switch (opType) {
+            case FLUSH:
+                lsmIndex.getIOOperationCallback().beforeOperation(LSMOperationType.FLUSH);
+                // Changing the flush status should *always* precede changing the mutable component.
+                lsmIndex.changeFlushStatusForCurrentMutableCompoent(false);
+                lsmIndex.changeMutableComponent();
+                // Notify all waiting threads whenever a flush has been scheduled since they will check 
+                // again if they can grab and enter the mutable component.
+                opTracker.notifyAll();
+                break;
+            case MERGE:
+                lsmIndex.getIOOperationCallback().beforeOperation(LSMOperationType.MERGE);
+            default:
+                break;
+        }
         opTracker.beforeOperation(lsmIndex, opType, ctx.getSearchOperationCallback(), ctx.getModificationCallback());
         return true;
     }
 
-    private void exitComponents(ILSMIndexOperationContext ctx, LSMOperationType opType, boolean failedOperation)
-            throws HyracksDataException {
-        try {
-            for (ILSMComponent c : ctx.getComponentHolder()) {
-                c.threadExit(opType, failedOperation);
+    private void exitComponents(ILSMIndexOperationContext ctx, LSMOperationType opType, ILSMComponent newComponent,
+            boolean failedOperation) throws HyracksDataException, IndexException {
+        synchronized (opTracker) {
+            try {
+                int i = 0;
+                // First check if there is any action that is needed to be taken based on the state of each component.
+                for (ILSMComponent c : ctx.getComponentHolder()) {
+                    boolean isMutableComponent = i == 0 && c.getType() == LSMComponentType.MEMORY ? true : false;
+                    c.threadExit(opType, failedOperation, isMutableComponent);
+                    if (c.getType() == LSMComponentType.MEMORY) {
+                        switch (c.getState()) {
+                            case READABLE_UNWRITABLE:
+                                if (isMutableComponent
+                                        && (opType == LSMOperationType.MODIFICATION || opType == LSMOperationType.FORCE_MODIFICATION)) {
+                                    lsmIndex.changeFlushStatusForCurrentMutableCompoent(true);
+                                }
+                                break;
+                            case INACTIVE:
+                                ((AbstractMemoryLSMComponent) c).reset();
+                                // Notify all waiting threads whenever the mutable component's has change to inactive. This is important because
+                                // even though we switched the mutable components, it is possible that the component that we just switched
+                                // to is still busy flushing its data to disk. Thus, the notification that was issued upon scheduling the flush
+                                // is not enough. 
+                                opTracker.notifyAll();
+                                break;
+                            default:
+                                break;
+                        }
+                    } else {
+                        switch (c.getState()) {
+                            case INACTIVE:
+                                ((AbstractDiskLSMComponent) c).destroy();
+                                break;
+                            default:
+                                break;
+                        }
+                    }
+                    i++;
+                }
+                // Then, perform any action that is needed to be taken based on the operation type.
+                switch (opType) {
+                    case FLUSH:
+                        // newComponent is null if the flush op. was not performed.
+                        if (newComponent != null) {
+                            lsmIndex.addComponent(newComponent);
+                            mergePolicy.diskComponentAdded(lsmIndex);
+                        }
+                        break;
+                    case MERGE:
+                        // newComponent is null if the merge op. was not performed.
+                        if (newComponent != null) {
+                            lsmIndex.subsumeMergedComponents(newComponent, ctx.getComponentHolder());
+                        }
+                        break;
+                    default:
+                        break;
+                }
+            } finally {
+                opTracker.afterOperation(lsmIndex, opType, ctx.getSearchOperationCallback(),
+                        ctx.getModificationCallback());
             }
-        } finally {
-            threadExit(ctx, opType);
         }
     }
 
@@ -129,10 +220,12 @@
         }
         try {
             lsmIndex.modify(ctx, tuple);
+            // The mutable component is always in the first index.
+            AbstractMemoryLSMComponent mutableComponent = (AbstractMemoryLSMComponent) ctx.getComponentHolder().get(0);
+            mutableComponent.setIsModified();
         } finally {
-            exitComponents(ctx, opType, false);
+            exitComponents(ctx, opType, null, false);
         }
-
         return true;
     }
 
@@ -143,11 +236,8 @@
         getAndEnterComponents(ctx, opType, false);
         try {
             lsmIndex.search(ctx, cursor, pred);
-        } catch (HyracksDataException e) {
-            exitComponents(ctx, opType, true);
-            throw e;
-        } catch (IndexException e) {
-            exitComponents(ctx, opType, true);
+        } catch (HyracksDataException | IndexException e) {
+            exitComponents(ctx, opType, null, true);
             throw e;
         }
     }
@@ -155,95 +245,86 @@
     @Override
     public void endSearch(ILSMIndexOperationContext ctx) throws HyracksDataException {
         if (ctx.getOperation() == IndexOperation.SEARCH) {
-            exitComponents(ctx, LSMOperationType.SEARCH, false);
+            try {
+                exitComponents(ctx, LSMOperationType.SEARCH, null, false);
+            } catch (IndexException e) {
+                throw new HyracksDataException(e);
+            }
         }
     }
 
     @Override
-    public void noOp(ILSMIndexOperationContext ctx) throws HyracksDataException {
-        LSMOperationType opType = LSMOperationType.NOOP;
-        opTracker.beforeOperation(lsmIndex, opType, ctx.getSearchOperationCallback(), ctx.getModificationCallback());
-        threadExit(ctx, opType);
-    }
-
-    @Override
     public void scheduleFlush(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
             throws HyracksDataException {
         if (!getAndEnterComponents(ctx, LSMOperationType.FLUSH, true)) {
+            callback.afterFinalize(LSMOperationType.FLUSH, null);
             return;
         }
-
-        lsmIndex.setFlushStatus(false);
-
-        if (!lsmIndex.scheduleFlush(ctx, callback)) {
-            callback.beforeOperation();
-            callback.afterOperation(null, null);
-            callback.afterFinalize(null);
-            exitComponents(ctx, LSMOperationType.FLUSH, false);
-        }
+        lsmIndex.scheduleFlush(ctx, callback);
     }
 
     @Override
     public void flush(ILSMIndexOperationContext ctx, ILSMIOOperation operation) throws HyracksDataException,
             IndexException {
-        operation.getCallback().beforeOperation();
         if (LOGGER.isLoggable(Level.INFO)) {
-            LOGGER.info(lsmIndex + ": flushing");
+            LOGGER.info("Started a flush operation for index: " + lsmIndex + " ...");
         }
-        ILSMComponent newComponent = lsmIndex.flush(operation);
 
-        operation.getCallback().afterOperation(null, newComponent);
-        lsmIndex.markAsValid(newComponent);
-        operation.getCallback().afterFinalize(newComponent);
-
-        lsmIndex.addComponent(newComponent);
-        int numComponents = lsmIndex.getImmutableComponents().size();
-
-        mergePolicy.diskComponentAdded(lsmIndex, numComponents);
-        exitComponents(ctx, LSMOperationType.FLUSH, false);
+        ILSMComponent newComponent = null;
+        try {
+            newComponent = lsmIndex.flush(operation);
+            operation.getCallback().afterOperation(LSMOperationType.FLUSH, null, newComponent);
+            lsmIndex.markAsValid(newComponent);
+        } finally {
+            exitComponents(ctx, LSMOperationType.FLUSH, newComponent, false);
+            operation.getCallback().afterFinalize(LSMOperationType.FLUSH, newComponent);
+        }
+        if (LOGGER.isLoggable(Level.INFO)) {
+            LOGGER.info("Finished the flush operation for index: " + lsmIndex);
+        }
     }
 
     @Override
     public void scheduleMerge(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
             throws HyracksDataException, IndexException {
-        LSMOperationType opType = LSMOperationType.MERGE;
-        if (!getAndEnterComponents(ctx, opType, false)) {
+        // Merge should always be a try operation, because it should never fail to enter the components unless the merge policy is erroneous.
+        if (!getAndEnterComponents(ctx, LSMOperationType.MERGE, true)) {
+            callback.afterFinalize(LSMOperationType.MERGE, null);
             return;
         }
-        if (ctx.getComponentHolder().size() > 1) {
-            lsmIndex.scheduleMerge(ctx, callback);
-        } else {
-            exitComponents(ctx, opType, true);
-        }
+        lsmIndex.scheduleMerge(ctx, callback);
     }
 
     @Override
     public void merge(ILSMIndexOperationContext ctx, ILSMIOOperation operation) throws HyracksDataException,
             IndexException {
-        List<ILSMComponent> mergedComponents = new ArrayList<ILSMComponent>();
-        operation.getCallback().beforeOperation();
         if (LOGGER.isLoggable(Level.INFO)) {
-            LOGGER.info(lsmIndex + ": merging");
+            LOGGER.info("Started a merge operation for index: " + lsmIndex + " ...");
         }
-        ILSMComponent newComponent = lsmIndex.merge(mergedComponents, operation);
-        ctx.getComponentHolder().addAll(mergedComponents);
-        operation.getCallback().afterOperation(mergedComponents, newComponent);
-        lsmIndex.markAsValid(newComponent);
-        operation.getCallback().afterFinalize(newComponent);
-        lsmIndex.subsumeMergedComponents(newComponent, mergedComponents);
-        exitComponents(ctx, LSMOperationType.MERGE, false);
+
+        ILSMComponent newComponent = null;
+        try {
+            newComponent = lsmIndex.merge(operation);
+            operation.getCallback().afterOperation(LSMOperationType.MERGE, ctx.getComponentHolder(), newComponent);
+            lsmIndex.markAsValid(newComponent);
+        } finally {
+            exitComponents(ctx, LSMOperationType.MERGE, newComponent, false);
+            operation.getCallback().afterFinalize(LSMOperationType.MERGE, newComponent);
+        }
+        if (LOGGER.isLoggable(Level.INFO)) {
+            LOGGER.info("Finished the merge operation for index: " + lsmIndex);
+        }
     }
 
     @Override
     public void addBulkLoadedComponent(ILSMComponent c) throws HyracksDataException, IndexException {
         lsmIndex.markAsValid(c);
         lsmIndex.addComponent(c);
-        int numComponents = lsmIndex.getImmutableComponents().size();
-        mergePolicy.diskComponentAdded(lsmIndex, numComponents);
+        mergePolicy.diskComponentAdded(lsmIndex);
     }
 
     @Override
     public ILSMOperationTracker getOperationTracker() {
         return opTracker;
     }
-}
+}
\ No newline at end of file
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMIndexSearchCursor.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMIndexSearchCursor.java
index b6ca21b..45cc69b 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMIndexSearchCursor.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMIndexSearchCursor.java
@@ -39,7 +39,7 @@
     protected PriorityQueueComparator pqCmp;
     protected MultiComparator cmp;
     protected boolean needPush;
-    protected boolean includeMemComponent;
+    protected boolean includeMutableComponent;
     protected ILSMHarness lsmHarness;
     protected final ILSMIndexOperationContext opCtx;
 
@@ -51,6 +51,10 @@
         needPush = false;
     }
 
+    public ILSMIndexOperationContext getOpCtx() {
+        return opCtx;
+    }
+
     public void initPriorityQueue() throws HyracksDataException, IndexException {
         int pqInitSize = (rangeCursors.length > 0) ? rangeCursors.length : 1;
         outputPriorityQueue = new PriorityQueue<PriorityQueueElement>(pqInitSize, pqCmp);
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMOperationType.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMOperationType.java
index d932e6d..853b6d0 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMOperationType.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMOperationType.java
@@ -19,6 +19,5 @@
     MODIFICATION,
     FORCE_MODIFICATION,
     FLUSH,
-    MERGE,
-    NOOP
+    MERGE
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMTreeIndexAccessor.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMTreeIndexAccessor.java
index 6328b1d..f11a061 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMTreeIndexAccessor.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMTreeIndexAccessor.java
@@ -122,11 +122,6 @@
     }
 
     @Override
-    public void noOp() throws HyracksDataException {
-        lsmHarness.noOp(ctx);
-    }
-
-    @Override
     public void forcePhysicalDelete(ITupleReference tuple) throws HyracksDataException, IndexException {
         ctx.setOperation(IndexOperation.PHYSICALDELETE);
         lsmHarness.forceModify(ctx, tuple);
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoMergePolicy.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoMergePolicy.java
index 80ac6d8..17d1b17 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoMergePolicy.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoMergePolicy.java
@@ -21,7 +21,7 @@
     INSTANCE;
 
     @Override
-    public void diskComponentAdded(ILSMIndex index, int totalNumDiskComponents) {
+    public void diskComponentAdded(ILSMIndex index) {
         // Do nothing
     }
 
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoOpIOOperationCallback.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoOpIOOperationCallback.java
index a43b44b..2c8369e 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoOpIOOperationCallback.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoOpIOOperationCallback.java
@@ -19,25 +19,26 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
 
-public enum NoOpIOOperationCallback implements ILSMIOOperationCallback, ILSMIOOperationCallbackProvider {
+public enum NoOpIOOperationCallback implements ILSMIOOperationCallback, ILSMIOOperationCallbackProvider, ILSMIOOperationCallbackFactory {
     INSTANCE;
 
     @Override
-    public void beforeOperation() throws HyracksDataException {
+    public void beforeOperation(LSMOperationType opType) throws HyracksDataException {
         // Do nothing.
     }
 
     @Override
-    public void afterOperation(List<ILSMComponent> oldComponents, ILSMComponent newComponent)
+    public void afterOperation(LSMOperationType opType, List<ILSMComponent> oldComponents, ILSMComponent newComponent)
             throws HyracksDataException {
         // Do nothing.
     }
 
     @Override
-    public void afterFinalize(ILSMComponent newComponent) throws HyracksDataException {
+    public void afterFinalize(LSMOperationType opType, ILSMComponent newComponent) throws HyracksDataException {
         // Do nothing.
     }
 
@@ -45,4 +46,14 @@
     public ILSMIOOperationCallback getIOOperationCallback(ILSMIndex index) {
         return INSTANCE;
     }
+
+    @Override
+    public ILSMIOOperationCallback createIOOperationCallback() {
+        return INSTANCE;
+    }
+
+    @Override
+    public void setNumOfMutableComponents(int count) {
+        // Do nothing.
+    }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/SynchronousScheduler.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/SynchronousScheduler.java
index 5eb63a9..44c20f5 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/SynchronousScheduler.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/SynchronousScheduler.java
@@ -25,7 +25,7 @@
     @Override
     public void scheduleOperation(ILSMIOOperation operation) throws HyracksDataException {
         try {
-            operation.perform();
+            operation.call();
         } catch (IndexException e) {
             throw new HyracksDataException(e);
         }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ThreadCountingTracker.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ThreadCountingTracker.java
index 19ee4b8..db75d7b 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ThreadCountingTracker.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ThreadCountingTracker.java
@@ -22,6 +22,7 @@
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexAccessor;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexInternal;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
 
 public class ThreadCountingTracker implements ILSMOperationTracker {
@@ -51,7 +52,8 @@
             IModificationOperationCallback modificationCallback) throws HyracksDataException {
         // Flush will only be handled by last exiting thread.
         if (opType == LSMOperationType.MODIFICATION) {
-            if (threadRefCount.decrementAndGet() == 0 && index.getFlushStatus()) {
+            if (threadRefCount.decrementAndGet() == 0
+                    && ((ILSMIndexInternal) index).hasFlushRequestForCurrentMutableComponent()) {
                 ILSMIndexAccessor accessor = (ILSMIndexAccessor) index.createAccessor(NoOpOperationCallback.INSTANCE,
                         NoOpOperationCallback.INSTANCE);
                 accessor.scheduleFlush(NoOpIOOperationCallback.INSTANCE);
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/VirtualBufferCache.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/VirtualBufferCache.java
index 18c87a1..bd3b278 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/VirtualBufferCache.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/VirtualBufferCache.java
@@ -41,7 +41,7 @@
     private final CacheBucket[] buckets;
     private final ArrayList<VirtualPage> pages;
 
-    private int nextFree;
+    private volatile int nextFree;
 
     private boolean open;
 
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/pom.xml b/hyracks/hyracks-storage-am-lsm-invertedindex/pom.xml
index 6fd62c1..9e5e91c 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/pom.xml
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/pom.xml
@@ -19,7 +19,7 @@
 	<parent>
 		<artifactId>hyracks</artifactId>
 		<groupId>edu.uci.ics.hyracks</groupId>
-		<version>0.2.7-SNAPSHOT</version>
+		<version>0.2.10-SNAPSHOT</version>
 		<relativePath>..</relativePath>
 	</parent>
 
@@ -40,14 +40,14 @@
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-storage-am-btree</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-storage-am-lsm-common</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 	    </dependency>
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelper.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelper.java
index 1afd9d5..ed2f8cf 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelper.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelper.java
@@ -14,12 +14,14 @@
  */
 package edu.uci.ics.hyracks.storage.am.lsm.invertedindex.dataflow;
 
+import java.util.List;
+
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
@@ -34,19 +36,19 @@
 public final class LSMInvertedIndexDataflowHelper extends AbstractLSMIndexDataflowHelper {
 
     public LSMInvertedIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            IVirtualBufferCache virtualBufferCache, ILSMMergePolicy mergePolicy,
+            List<IVirtualBufferCache> virtualBufferCaches, ILSMMergePolicy mergePolicy,
             ILSMOperationTrackerProvider opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        this(opDesc, ctx, partition, virtualBufferCache, DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE, mergePolicy,
-                opTrackerFactory, ioScheduler, ioOpCallbackProvider);
+            ILSMIOOperationCallbackFactory ioOpCallbackFactory) {
+        this(opDesc, ctx, partition, virtualBufferCaches, DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE, mergePolicy,
+                opTrackerFactory, ioScheduler, ioOpCallbackFactory);
     }
 
     public LSMInvertedIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            IVirtualBufferCache virtualBufferCache, double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy,
-            ILSMOperationTrackerProvider opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        super(opDesc, ctx, partition, virtualBufferCache, bloomFilterFalsePositiveRate, mergePolicy, opTrackerFactory,
-                ioScheduler, ioOpCallbackProvider);
+            List<IVirtualBufferCache> virtualBufferCaches, double bloomFilterFalsePositiveRate,
+            ILSMMergePolicy mergePolicy, ILSMOperationTrackerProvider opTrackerFactory,
+            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackFactory ioOpCallbackFactory) {
+        super(opDesc, ctx, partition, virtualBufferCaches, bloomFilterFalsePositiveRate, mergePolicy, opTrackerFactory,
+                ioScheduler, ioOpCallbackFactory);
     }
 
     @Override
@@ -55,12 +57,13 @@
         try {
             IBufferCache diskBufferCache = opDesc.getStorageManager().getBufferCache(ctx);
             IFileMapProvider diskFileMapProvider = opDesc.getStorageManager().getFileMapProvider(ctx);
-            LSMInvertedIndex invIndex = InvertedIndexUtils.createLSMInvertedIndex(virtualBufferCache,
+            LSMInvertedIndex invIndex = InvertedIndexUtils.createLSMInvertedIndex(virtualBufferCaches,
                     diskFileMapProvider, invIndexOpDesc.getInvListsTypeTraits(),
                     invIndexOpDesc.getInvListsComparatorFactories(), invIndexOpDesc.getTokenTypeTraits(),
                     invIndexOpDesc.getTokenComparatorFactories(), invIndexOpDesc.getTokenizerFactory(),
                     diskBufferCache, file.getFile().getPath(), bloomFilterFalsePositiveRate, mergePolicy,
-                    opTrackerFactory.getOperationTracker(ctx), ioScheduler, ioOpCallbackProvider);
+                    opTrackerFactory.getOperationTracker(ctx), ioScheduler,
+                    ioOpCallbackFactory.createIOOperationCallback());
             return invIndex;
         } catch (IndexException e) {
             throw new HyracksDataException(e);
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelperFactory.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelperFactory.java
index c9f81fc..84c7150 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelperFactory.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelperFactory.java
@@ -18,7 +18,7 @@
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IndexDataflowHelper;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
@@ -31,19 +31,19 @@
 
     public LSMInvertedIndexDataflowHelperFactory(IVirtualBufferCacheProvider virtualBufferCacheProvider,
             ILSMMergePolicyProvider mergePolicyProvider, ILSMOperationTrackerProvider opTrackerProvider,
-            ILSMIOOperationSchedulerProvider ioSchedulerProvider, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
+            ILSMIOOperationSchedulerProvider ioSchedulerProvider, ILSMIOOperationCallbackFactory ioOpCallbackFactory,
             double bloomFilterFalsePositiveRate) {
         super(virtualBufferCacheProvider, mergePolicyProvider, opTrackerProvider, ioSchedulerProvider,
-                ioOpCallbackProvider, bloomFilterFalsePositiveRate);
+                ioOpCallbackFactory, bloomFilterFalsePositiveRate);
     }
 
     @Override
     public IndexDataflowHelper createIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
             int partition) {
         return new LSMInvertedIndexDataflowHelper(opDesc, ctx, partition,
-                virtualBufferCacheProvider.getVirtualBufferCache(ctx), bloomFilterFalsePositiveRate,
+                virtualBufferCacheProvider.getVirtualBufferCaches(ctx), bloomFilterFalsePositiveRate,
                 mergePolicyProvider.getMergePolicy(ctx), opTrackerFactory, ioSchedulerProvider.getIOScheduler(ctx),
-                ioOpCallbackProvider);
+                ioOpCallbackFactory);
     }
 
 }
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/PartitionedLSMInvertedIndexDataflowHelper.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/PartitionedLSMInvertedIndexDataflowHelper.java
index 0dbd06b..57a41ca 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/PartitionedLSMInvertedIndexDataflowHelper.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/PartitionedLSMInvertedIndexDataflowHelper.java
@@ -14,12 +14,14 @@
  */
 package edu.uci.ics.hyracks.storage.am.lsm.invertedindex.dataflow;
 
+import java.util.List;
+
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
@@ -34,19 +36,19 @@
 public final class PartitionedLSMInvertedIndexDataflowHelper extends AbstractLSMIndexDataflowHelper {
 
     public PartitionedLSMInvertedIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
-            int partition, IVirtualBufferCache virtualBufferCache, ILSMMergePolicy mergePolicy,
+            int partition, List<IVirtualBufferCache> virtualBufferCache, ILSMMergePolicy mergePolicy,
             ILSMOperationTrackerProvider opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
+            ILSMIOOperationCallbackFactory ioOpCallbackFactory) {
         this(opDesc, ctx, partition, virtualBufferCache, DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE, mergePolicy,
-                opTrackerFactory, ioScheduler, ioOpCallbackProvider);
+                opTrackerFactory, ioScheduler, ioOpCallbackFactory);
     }
 
     public PartitionedLSMInvertedIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
-            int partition, IVirtualBufferCache virtualBufferCache, double bloomFilterFalsePositiveRate,
+            int partition, List<IVirtualBufferCache> virtualBufferCaches, double bloomFilterFalsePositiveRate,
             ILSMMergePolicy mergePolicy, ILSMOperationTrackerProvider opTrackerFactory,
-            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        super(opDesc, ctx, partition, virtualBufferCache, bloomFilterFalsePositiveRate, mergePolicy, opTrackerFactory,
-                ioScheduler, ioOpCallbackProvider);
+            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackFactory ioOpCallbackFactory) {
+        super(opDesc, ctx, partition, virtualBufferCaches, bloomFilterFalsePositiveRate, mergePolicy, opTrackerFactory,
+                ioScheduler, ioOpCallbackFactory);
     }
 
     @Override
@@ -56,11 +58,12 @@
             IBufferCache diskBufferCache = opDesc.getStorageManager().getBufferCache(ctx);
             IFileMapProvider diskFileMapProvider = opDesc.getStorageManager().getFileMapProvider(ctx);
             PartitionedLSMInvertedIndex invIndex = InvertedIndexUtils.createPartitionedLSMInvertedIndex(
-                    virtualBufferCache, diskFileMapProvider, invIndexOpDesc.getInvListsTypeTraits(),
+                    virtualBufferCaches, diskFileMapProvider, invIndexOpDesc.getInvListsTypeTraits(),
                     invIndexOpDesc.getInvListsComparatorFactories(), invIndexOpDesc.getTokenTypeTraits(),
                     invIndexOpDesc.getTokenComparatorFactories(), invIndexOpDesc.getTokenizerFactory(),
                     diskBufferCache, file.getFile().getPath(), bloomFilterFalsePositiveRate, mergePolicy,
-                    opTrackerFactory.getOperationTracker(ctx), ioScheduler, ioOpCallbackProvider);
+                    opTrackerFactory.getOperationTracker(ctx), ioScheduler,
+                    ioOpCallbackFactory.createIOOperationCallback());
             return invIndex;
         } catch (IndexException e) {
             throw new HyracksDataException(e);
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/PartitionedLSMInvertedIndexDataflowHelperFactory.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/PartitionedLSMInvertedIndexDataflowHelperFactory.java
index 67cab6d..d78ae7e 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/PartitionedLSMInvertedIndexDataflowHelperFactory.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/PartitionedLSMInvertedIndexDataflowHelperFactory.java
@@ -18,7 +18,7 @@
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IndexDataflowHelper;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
@@ -31,18 +31,18 @@
 
     public PartitionedLSMInvertedIndexDataflowHelperFactory(IVirtualBufferCacheProvider virtualBufferCacheProvider,
             ILSMMergePolicyProvider mergePolicyProvider, ILSMOperationTrackerProvider opTrackerProvider,
-            ILSMIOOperationSchedulerProvider ioSchedulerProvider, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
+            ILSMIOOperationSchedulerProvider ioSchedulerProvider, ILSMIOOperationCallbackFactory ioOpCallbackFactory,
             double bloomFilterFalsePositiveRate) {
         super(virtualBufferCacheProvider, mergePolicyProvider, opTrackerProvider, ioSchedulerProvider,
-                ioOpCallbackProvider, bloomFilterFalsePositiveRate);
+                ioOpCallbackFactory, bloomFilterFalsePositiveRate);
     }
 
     @Override
     public IndexDataflowHelper createIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
             int partition) {
         return new PartitionedLSMInvertedIndexDataflowHelper(opDesc, ctx, partition,
-                virtualBufferCacheProvider.getVirtualBufferCache(ctx), bloomFilterFalsePositiveRate,
+                virtualBufferCacheProvider.getVirtualBufferCaches(ctx), bloomFilterFalsePositiveRate,
                 mergePolicyProvider.getMergePolicy(ctx), opTrackerFactory, ioSchedulerProvider.getIOScheduler(ctx),
-                ioOpCallbackProvider);
+                ioOpCallbackFactory);
     }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java
index 3eae5a7..cef6aee 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java
@@ -27,7 +27,6 @@
 import edu.uci.ics.hyracks.storage.am.bloomfilter.impls.BloomCalculations;
 import edu.uci.ics.hyracks.storage.am.bloomfilter.impls.BloomFilterFactory;
 import edu.uci.ics.hyracks.storage.am.bloomfilter.impls.BloomFilterSpecification;
-import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeDuplicateKeyException;
 import edu.uci.ics.hyracks.storage.am.btree.frames.BTreeLeafFrameType;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree.BTreeAccessor;
@@ -43,15 +42,16 @@
 import edu.uci.ics.hyracks.storage.am.common.api.ISearchPredicate;
 import edu.uci.ics.hyracks.storage.am.common.api.IVirtualFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.am.common.exceptions.TreeIndexDuplicateKeyException;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
 import edu.uci.ics.hyracks.storage.am.common.tuples.PermutingTupleReference;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent.LSMComponentType;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponentFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperation;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexAccessorInternal;
@@ -65,6 +65,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BTreeFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BlockingIOOperationCallbackWrapper;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMComponentFileReferences;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMIndexSearchCursor;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedListCursor;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.inmemory.InMemoryInvertedIndex;
@@ -79,9 +80,6 @@
 
 public class LSMInvertedIndex extends AbstractLSMIndex implements IInvertedIndex {
 
-    // In-memory components.
-    protected final LSMInvertedIndexMutableComponent mutableComponent;
-    protected final IVirtualFreePageManager virtualFreePageManager;
     protected final IBinaryTokenizerFactory tokenizerFactory;
 
     // On-disk components.
@@ -94,31 +92,39 @@
     protected final ITypeTraits[] tokenTypeTraits;
     protected final IBinaryComparatorFactory[] tokenCmpFactories;
 
-    public LSMInvertedIndex(IVirtualBufferCache virtualBufferCache, OnDiskInvertedIndexFactory diskInvIndexFactory,
-            BTreeFactory deletedKeysBTreeFactory, BloomFilterFactory bloomFilterFactory,
-            double bloomFilterFalsePositiveRate, ILSMIndexFileManager fileManager,
-            IFileMapProvider diskFileMapProvider, ITypeTraits[] invListTypeTraits,
+    public LSMInvertedIndex(List<IVirtualBufferCache> virtualBufferCaches,
+            OnDiskInvertedIndexFactory diskInvIndexFactory, BTreeFactory deletedKeysBTreeFactory,
+            BloomFilterFactory bloomFilterFactory, double bloomFilterFalsePositiveRate,
+            ILSMIndexFileManager fileManager, IFileMapProvider diskFileMapProvider, ITypeTraits[] invListTypeTraits,
             IBinaryComparatorFactory[] invListCmpFactories, ITypeTraits[] tokenTypeTraits,
             IBinaryComparatorFactory[] tokenCmpFactories, IBinaryTokenizerFactory tokenizerFactory,
             ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider) throws IndexException {
-        super(virtualBufferCache, diskInvIndexFactory.getBufferCache(), fileManager, diskFileMapProvider,
-                bloomFilterFalsePositiveRate, mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider);
-        this.virtualFreePageManager = new VirtualFreePageManager(virtualBufferCache.getNumPages());
+            ILSMIOOperationCallback ioOpCallback) throws IndexException {
+        super(virtualBufferCaches, diskInvIndexFactory.getBufferCache(), fileManager, diskFileMapProvider,
+                bloomFilterFalsePositiveRate, mergePolicy, opTracker, ioScheduler, ioOpCallback);
+
         this.tokenizerFactory = tokenizerFactory;
         this.invListTypeTraits = invListTypeTraits;
         this.invListCmpFactories = invListCmpFactories;
         this.tokenTypeTraits = tokenTypeTraits;
         this.tokenCmpFactories = tokenCmpFactories;
-        // Create in-memory component.
-        InMemoryInvertedIndex memInvIndex = createInMemoryInvertedIndex(virtualBufferCache);
-        BTree deleteKeysBTree = BTreeUtils.createBTree(virtualBufferCache, new VirtualFreePageManager(
-                virtualBufferCache.getNumPages()), ((IVirtualBufferCache) virtualBufferCache).getFileMapProvider(),
-                invListTypeTraits, invListCmpFactories, BTreeLeafFrameType.REGULAR_NSM, new FileReference(new File(
-                        fileManager.getBaseDir() + "_virtual_del")));
-        mutableComponent = new LSMInvertedIndexMutableComponent(memInvIndex, deleteKeysBTree, virtualBufferCache);
-        componentFactory = new LSMInvertedIndexComponentFactory(diskInvIndexFactory, deletedKeysBTreeFactory,
+
+        componentFactory = new LSMInvertedIndexDiskComponentFactory(diskInvIndexFactory, deletedKeysBTreeFactory,
                 bloomFilterFactory);
+
+        int i = 0;
+        for (IVirtualBufferCache virtualBufferCache : virtualBufferCaches) {
+            InMemoryInvertedIndex memInvIndex = createInMemoryInvertedIndex(virtualBufferCache,
+                    new VirtualFreePageManager(virtualBufferCache.getNumPages()), i);
+            BTree deleteKeysBTree = BTreeUtils.createBTree(virtualBufferCache, new VirtualFreePageManager(
+                    virtualBufferCache.getNumPages()), ((IVirtualBufferCache) virtualBufferCache).getFileMapProvider(),
+                    invListTypeTraits, invListCmpFactories, BTreeLeafFrameType.REGULAR_NSM, new FileReference(new File(
+                            fileManager.getBaseDir() + "_virtual_del_" + i)));
+            LSMInvertedIndexMemoryComponent mutableComponent = new LSMInvertedIndexMemoryComponent(memInvIndex,
+                    deleteKeysBTree, virtualBufferCache, i == 0 ? true : false);
+            memoryComponents.add(mutableComponent);
+            ++i;
+        }
     }
 
     @Override
@@ -129,7 +135,7 @@
 
         fileManager.deleteDirs();
         fileManager.createDirs();
-        componentsRef.get().clear();
+        diskComponents.clear();
     }
 
     @Override
@@ -139,16 +145,20 @@
         }
 
         try {
-            List<ILSMComponent> immutableComponents = componentsRef.get();
-            ((IVirtualBufferCache) mutableComponent.getInvIndex().getBufferCache()).open();
-            mutableComponent.getInvIndex().create();
-            mutableComponent.getInvIndex().activate();
-            mutableComponent.getDeletedKeysBTree().create();
-            mutableComponent.getDeletedKeysBTree().activate();
+            List<ILSMComponent> immutableComponents = diskComponents;
+            for (ILSMComponent c : memoryComponents) {
+                LSMInvertedIndexMemoryComponent mutableComponent = (LSMInvertedIndexMemoryComponent) c;
+                ((IVirtualBufferCache) mutableComponent.getInvIndex().getBufferCache()).open();
+                mutableComponent.getInvIndex().create();
+                mutableComponent.getInvIndex().activate();
+                mutableComponent.getDeletedKeysBTree().create();
+                mutableComponent.getDeletedKeysBTree().activate();
+            }
+
             immutableComponents.clear();
             List<LSMComponentFileReferences> validFileReferences = fileManager.cleanupAndGetValidFiles();
             for (LSMComponentFileReferences lsmComonentFileReference : validFileReferences) {
-                LSMInvertedIndexImmutableComponent component;
+                LSMInvertedIndexDiskComponent component;
                 try {
                     component = createDiskInvIndexComponent(componentFactory,
                             lsmComonentFileReference.getInsertIndexFileReference(),
@@ -171,12 +181,16 @@
         if (!isActivated) {
             throw new HyracksDataException("Failed to clear the index since it is not activated.");
         }
-        List<ILSMComponent> immutableComponents = componentsRef.get();
-        mutableComponent.getInvIndex().clear();
-        mutableComponent.getDeletedKeysBTree().clear();
-        mutableComponent.reset();
+
+        for (ILSMComponent c : memoryComponents) {
+            LSMInvertedIndexMemoryComponent mutableComponent = (LSMInvertedIndexMemoryComponent) c;
+            mutableComponent.getInvIndex().clear();
+            mutableComponent.getDeletedKeysBTree().clear();
+            mutableComponent.reset();
+        }
+        List<ILSMComponent> immutableComponents = diskComponents;
         for (ILSMComponent c : immutableComponents) {
-            LSMInvertedIndexImmutableComponent component = (LSMInvertedIndexImmutableComponent) c;
+            LSMInvertedIndexDiskComponent component = (LSMInvertedIndexDiskComponent) c;
             component.getBloomFilter().deactivate();
             component.getInvIndex().deactivate();
             component.getDeletedKeysBTree().deactivate();
@@ -195,30 +209,32 @@
 
         isActivated = false;
         if (flushOnExit) {
-            BlockingIOOperationCallbackWrapper blockingCallBack = new BlockingIOOperationCallbackWrapper(
-                    ioOpCallbackProvider.getIOOperationCallback(this));
-            ILSMIndexAccessor accessor = (ILSMIndexAccessor) createAccessor(NoOpOperationCallback.INSTANCE,
-                    NoOpOperationCallback.INSTANCE);
-            accessor.scheduleFlush(blockingCallBack);
+            BlockingIOOperationCallbackWrapper cb = new BlockingIOOperationCallbackWrapper(
+                    ioOpCallback);
+            ILSMIndexAccessor accessor = createAccessor(NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
+            accessor.scheduleFlush(cb);
             try {
-                blockingCallBack.waitForIO();
+                cb.waitForIO();
             } catch (InterruptedException e) {
                 throw new HyracksDataException(e);
             }
         }
 
-        List<ILSMComponent> immutableComponents = componentsRef.get();
+        List<ILSMComponent> immutableComponents = diskComponents;
         for (ILSMComponent c : immutableComponents) {
-            LSMInvertedIndexImmutableComponent component = (LSMInvertedIndexImmutableComponent) c;
+            LSMInvertedIndexDiskComponent component = (LSMInvertedIndexDiskComponent) c;
             component.getBloomFilter().deactivate();
             component.getInvIndex().deactivate();
             component.getDeletedKeysBTree().deactivate();
         }
-        mutableComponent.getInvIndex().deactivate();
-        mutableComponent.getDeletedKeysBTree().deactivate();
-        mutableComponent.getInvIndex().destroy();
-        mutableComponent.getDeletedKeysBTree().destroy();
-        ((IVirtualBufferCache) mutableComponent.getInvIndex().getBufferCache()).close();
+        for (ILSMComponent c : memoryComponents) {
+            LSMInvertedIndexMemoryComponent mutableComponent = (LSMInvertedIndexMemoryComponent) c;
+            mutableComponent.getInvIndex().deactivate();
+            mutableComponent.getDeletedKeysBTree().deactivate();
+            mutableComponent.getInvIndex().destroy();
+            mutableComponent.getDeletedKeysBTree().destroy();
+            ((IVirtualBufferCache) mutableComponent.getInvIndex().getBufferCache()).close();
+        }
     }
 
     @Override
@@ -232,11 +248,14 @@
             throw new HyracksDataException("Failed to destroy the index since it is activated.");
         }
 
-        mutableComponent.getInvIndex().destroy();
-        mutableComponent.getDeletedKeysBTree().destroy();
-        List<ILSMComponent> immutableComponents = componentsRef.get();
+        for (ILSMComponent c : memoryComponents) {
+            LSMInvertedIndexMemoryComponent mutableComponent = (LSMInvertedIndexMemoryComponent) c;
+            mutableComponent.getInvIndex().destroy();
+            mutableComponent.getDeletedKeysBTree().destroy();
+        }
+        List<ILSMComponent> immutableComponents = diskComponents;
         for (ILSMComponent c : immutableComponents) {
-            LSMInvertedIndexImmutableComponent component = (LSMInvertedIndexImmutableComponent) c;
+            LSMInvertedIndexDiskComponent component = (LSMInvertedIndexDiskComponent) c;
             component.getInvIndex().destroy();
             component.getDeletedKeysBTree().destroy();
             component.getBloomFilter().destroy();
@@ -246,17 +265,29 @@
 
     @Override
     public void getOperationalComponents(ILSMIndexOperationContext ctx) {
-        List<ILSMComponent> immutableComponents = componentsRef.get();
+        List<ILSMComponent> immutableComponents = diskComponents;
         List<ILSMComponent> operationalComponents = ctx.getComponentHolder();
         operationalComponents.clear();
+        int cmc = currentMutableComponentId.get();
+        ctx.setCurrentMutableComponentId(cmc);
+        int numMutableComponents = memoryComponents.size();
         switch (ctx.getOperation()) {
             case FLUSH:
             case DELETE:
             case INSERT:
-                operationalComponents.add(mutableComponent);
+                operationalComponents.add(memoryComponents.get(cmc));
                 break;
             case SEARCH:
-                operationalComponents.add(mutableComponent);
+                for (int i = 0; i < numMutableComponents - 1; i++) {
+                    ILSMComponent c = memoryComponents.get((cmc + i + 1) % numMutableComponents);
+                    LSMInvertedIndexMemoryComponent mutableComponent = (LSMInvertedIndexMemoryComponent) c;
+                    if (mutableComponent.isReadable()) {
+                        // Make sure newest components are added first
+                        operationalComponents.add(0, mutableComponent);
+                    }
+                }
+                // The current mutable component is always added
+                operationalComponents.add(0, memoryComponents.get(cmc));
                 operationalComponents.addAll(immutableComponents);
                 break;
             case MERGE:
@@ -295,17 +326,17 @@
         switch (ctx.getOperation()) {
             case INSERT: {
                 // Insert into the in-memory inverted index.                
-                ctx.memInvIndexAccessor.insert(tuple);
+                ctx.currentMutableInvIndexAccessors.insert(tuple);
                 break;
             }
             case DELETE: {
                 // First remove all entries in the in-memory inverted index (if any).
-                ctx.memInvIndexAccessor.delete(tuple);
+                ctx.currentMutableInvIndexAccessors.delete(tuple);
                 // Insert key into the deleted-keys BTree.
                 ctx.keysOnlyTuple.reset(tuple);
                 try {
-                    ctx.deletedKeysBTreeAccessor.insert(ctx.keysOnlyTuple);
-                } catch (BTreeDuplicateKeyException e) {
+                    ctx.currentDeletedKeysBTreeAccessors.insert(ctx.keysOnlyTuple);
+                } catch (TreeIndexDuplicateKeyException e) {
                     // Key has already been deleted.
                 }
                 break;
@@ -314,7 +345,6 @@
                 throw new UnsupportedOperationException("Operation " + ctx.getOperation() + " not supported.");
             }
         }
-        mutableComponent.setIsModified();
     }
 
     @Override
@@ -323,58 +353,59 @@
         List<ILSMComponent> operationalComponents = ictx.getComponentHolder();
         int numComponents = operationalComponents.size();
         assert numComponents > 0;
-        boolean includeMutableComponent = operationalComponents.get(0) == mutableComponent;
+        boolean includeMutableComponent = false;
         ArrayList<IIndexAccessor> indexAccessors = new ArrayList<IIndexAccessor>(numComponents);
         ArrayList<IIndexAccessor> deletedKeysBTreeAccessors = new ArrayList<IIndexAccessor>(numComponents);
-        if (includeMutableComponent) {
-            IIndexAccessor invIndexAccessor = mutableComponent.getInvIndex().createAccessor(
-                    NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
-            indexAccessors.add(invIndexAccessor);
-            IIndexAccessor deletedKeysAccessor = mutableComponent.getDeletedKeysBTree().createAccessor(
-                    NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
-            deletedKeysBTreeAccessors.add(deletedKeysAccessor);
-        }
 
-        for (int i = includeMutableComponent ? 1 : 0; i < operationalComponents.size(); i++) {
-            LSMInvertedIndexImmutableComponent component = (LSMInvertedIndexImmutableComponent) operationalComponents
-                    .get(i);
-            IIndexAccessor invIndexAccessor = component.getInvIndex().createAccessor(NoOpOperationCallback.INSTANCE,
-                    NoOpOperationCallback.INSTANCE);
-            indexAccessors.add(invIndexAccessor);
-            IIndexAccessor deletedKeysAccessor = component.getDeletedKeysBTree().createAccessor(
-                    NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
-            deletedKeysBTreeAccessors.add(deletedKeysAccessor);
+        for (int i = 0; i < operationalComponents.size(); i++) {
+            ILSMComponent component = operationalComponents.get(i);
+            if (component.getType() == LSMComponentType.MEMORY) {
+                includeMutableComponent = true;
+                IIndexAccessor invIndexAccessor = ((LSMInvertedIndexMemoryComponent) component).getInvIndex()
+                        .createAccessor(NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
+                indexAccessors.add(invIndexAccessor);
+                IIndexAccessor deletedKeysAccessor = ((LSMInvertedIndexMemoryComponent) component)
+                        .getDeletedKeysBTree().createAccessor(NoOpOperationCallback.INSTANCE,
+                                NoOpOperationCallback.INSTANCE);
+                deletedKeysBTreeAccessors.add(deletedKeysAccessor);
+            } else {
+                IIndexAccessor invIndexAccessor = ((LSMInvertedIndexDiskComponent) component).getInvIndex()
+                        .createAccessor(NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
+                indexAccessors.add(invIndexAccessor);
+                IIndexAccessor deletedKeysAccessor = ((LSMInvertedIndexDiskComponent) component).getDeletedKeysBTree()
+                        .createAccessor(NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
+                deletedKeysBTreeAccessors.add(deletedKeysAccessor);
+            }
         }
 
         ICursorInitialState initState = createCursorInitialState(pred, ictx, includeMutableComponent, indexAccessors,
-                deletedKeysBTreeAccessors);
+                deletedKeysBTreeAccessors, operationalComponents);
         cursor.open(initState, pred);
     }
 
     private ICursorInitialState createCursorInitialState(ISearchPredicate pred, IIndexOperationContext ictx,
             boolean includeMutableComponent, ArrayList<IIndexAccessor> indexAccessors,
-            ArrayList<IIndexAccessor> deletedKeysBTreeAccessors) {
-        List<ILSMComponent> immutableComponents = componentsRef.get();
+            ArrayList<IIndexAccessor> deletedKeysBTreeAccessors, List<ILSMComponent> operationalComponents) {
         ICursorInitialState initState = null;
         PermutingTupleReference keysOnlyTuple = createKeysOnlyTupleReference();
         MultiComparator keyCmp = MultiComparator.createIgnoreFieldLength(invListCmpFactories);
-        List<ILSMComponent> operationalComponents = new ArrayList<ILSMComponent>();
-        if (includeMutableComponent) {
-            operationalComponents.add(mutableComponent);
-        }
-        operationalComponents.addAll(immutableComponents);
 
         // TODO: This check is not pretty, but it does the job. Come up with something more OO in the future.
         // Distinguish between regular searches and range searches (mostly used in merges).
         if (pred instanceof InvertedIndexSearchPredicate) {
             initState = new LSMInvertedIndexSearchCursorInitialState(keyCmp, keysOnlyTuple, indexAccessors,
-                    deletedKeysBTreeAccessors, mutableComponent.getDeletedKeysBTree().getLeafFrameFactory(), ictx,
-                    includeMutableComponent, lsmHarness, operationalComponents);
+                    deletedKeysBTreeAccessors,
+                    ((LSMInvertedIndexMemoryComponent) memoryComponents.get(currentMutableComponentId.get()))
+                            .getDeletedKeysBTree().getLeafFrameFactory(), ictx, includeMutableComponent, lsmHarness,
+                    operationalComponents);
         } else {
+            LSMInvertedIndexMemoryComponent mutableComponent = (LSMInvertedIndexMemoryComponent) memoryComponents
+                    .get(currentMutableComponentId.get());
             InMemoryInvertedIndex memInvIndex = (InMemoryInvertedIndex) mutableComponent.getInvIndex();
             MultiComparator tokensAndKeysCmp = MultiComparator.create(memInvIndex.getBTree().getComparatorFactories());
             initState = new LSMInvertedIndexRangeSearchCursorInitialState(tokensAndKeysCmp, keyCmp, keysOnlyTuple,
-                    mutableComponent.getDeletedKeysBTree().getLeafFrameFactory(), includeMutableComponent, lsmHarness,
+                    ((LSMInvertedIndexMemoryComponent) memoryComponents.get(currentMutableComponentId.get()))
+                            .getDeletedKeysBTree().getLeafFrameFactory(), includeMutableComponent, lsmHarness,
                     indexAccessors, deletedKeysBTreeAccessors, pred, operationalComponents);
         }
         return initState;
@@ -394,22 +425,18 @@
     }
 
     @Override
-    public boolean scheduleFlush(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
+    public void scheduleFlush(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
             throws HyracksDataException {
-        if (!mutableComponent.isModified()) {
-            return false;
-        }
+        ILSMComponent flushingComponent = ctx.getComponentHolder().get(0);
         LSMComponentFileReferences componentFileRefs = fileManager.getRelFlushFileReference();
         LSMInvertedIndexOpContext opCtx = createOpContext(NoOpOperationCallback.INSTANCE,
                 NoOpOperationCallback.INSTANCE);
-        ILSMComponent flushingComponent = ctx.getComponentHolder().get(0);
         opCtx.setOperation(IndexOperation.FLUSH);
         opCtx.getComponentHolder().add(flushingComponent);
-        ioScheduler.scheduleOperation(new LSMInvertedIndexFlushOperation(new LSMInvertedIndexAccessor(this, lsmHarness,
-                fileManager, opCtx), mutableComponent, componentFileRefs.getInsertIndexFileReference(),
-                componentFileRefs.getDeleteIndexFileReference(), componentFileRefs.getBloomFilterFileReference(),
-                callback));
-        return true;
+        ioScheduler.scheduleOperation(new LSMInvertedIndexFlushOperation(
+                new LSMInvertedIndexAccessor(lsmHarness, opCtx), flushingComponent, componentFileRefs
+                        .getInsertIndexFileReference(), componentFileRefs.getDeleteIndexFileReference(),
+                componentFileRefs.getBloomFilterFileReference(), callback));
     }
 
     @Override
@@ -417,13 +444,14 @@
         LSMInvertedIndexFlushOperation flushOp = (LSMInvertedIndexFlushOperation) operation;
 
         // Create an inverted index instance to be bulk loaded.
-        LSMInvertedIndexImmutableComponent component = createDiskInvIndexComponent(componentFactory,
+        LSMInvertedIndexDiskComponent component = createDiskInvIndexComponent(componentFactory,
                 flushOp.getDictBTreeFlushTarget(), flushOp.getDeletedKeysBTreeFlushTarget(),
                 flushOp.getBloomFilterFlushTarget(), true);
         IInvertedIndex diskInvertedIndex = component.getInvIndex();
 
         // Create a scan cursor on the BTree underlying the in-memory inverted index.
-        LSMInvertedIndexMutableComponent flushingComponent = flushOp.getFlushingComponent();
+        LSMInvertedIndexMemoryComponent flushingComponent = (LSMInvertedIndexMemoryComponent) flushOp
+                .getFlushingComponent();
         InMemoryInvertedIndexAccessor memInvIndexAccessor = (InMemoryInvertedIndexAccessor) flushingComponent
                 .getInvIndex().createAccessor(NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
         BTreeAccessor memBTreeAccessor = memInvIndexAccessor.getBTreeAccessor();
@@ -496,44 +524,43 @@
     public void scheduleMerge(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
             throws HyracksDataException, IndexException {
         LSMInvertedIndexOpContext ictx = createOpContext(NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
-        List<ILSMComponent> mergingComponents = ctx.getComponentHolder();
-        ictx.getComponentHolder().addAll(mergingComponents);
-        IIndexCursor cursor = new LSMInvertedIndexRangeSearchCursor(ictx);
-        RangePredicate mergePred = new RangePredicate(null, null, true, true, null, null);
-
-        // Scan diskInvertedIndexes ignoring the memoryInvertedIndex.
-        search(ictx, cursor, mergePred);
-
         ictx.setOperation(IndexOperation.MERGE);
-        LSMInvertedIndexImmutableComponent firstComponent = (LSMInvertedIndexImmutableComponent) mergingComponents
-                .get(0);
+        List<ILSMComponent> mergingComponents = ctx.getComponentHolder();
+        IIndexCursor cursor = new LSMInvertedIndexRangeSearchCursor(ictx);
+
+        LSMInvertedIndexDiskComponent firstComponent = (LSMInvertedIndexDiskComponent) mergingComponents.get(0);
         OnDiskInvertedIndex firstInvIndex = (OnDiskInvertedIndex) firstComponent.getInvIndex();
         String firstFileName = firstInvIndex.getBTree().getFileReference().getFile().getName();
 
-        LSMInvertedIndexImmutableComponent lastComponent = (LSMInvertedIndexImmutableComponent) mergingComponents
+        LSMInvertedIndexDiskComponent lastComponent = (LSMInvertedIndexDiskComponent) mergingComponents
                 .get(mergingComponents.size() - 1);
         OnDiskInvertedIndex lastInvIndex = (OnDiskInvertedIndex) lastComponent.getInvIndex();
         String lastFileName = lastInvIndex.getBTree().getFileReference().getFile().getName();
 
         LSMComponentFileReferences relMergeFileRefs = fileManager.getRelMergeFileReference(firstFileName, lastFileName);
-        ILSMIndexAccessorInternal accessor = new LSMInvertedIndexAccessor(this, lsmHarness, fileManager, ictx);
+        ILSMIndexAccessorInternal accessor = new LSMInvertedIndexAccessor(lsmHarness, ctx);
         ioScheduler.scheduleOperation(new LSMInvertedIndexMergeOperation(accessor, mergingComponents, cursor,
                 relMergeFileRefs.getInsertIndexFileReference(), relMergeFileRefs.getDeleteIndexFileReference(),
                 relMergeFileRefs.getBloomFilterFileReference(), callback));
     }
 
     @Override
-    public ILSMComponent merge(List<ILSMComponent> mergedComponents, ILSMIOOperation operation)
-            throws HyracksDataException, IndexException {
+    public ILSMComponent merge(ILSMIOOperation operation) throws HyracksDataException, IndexException {
         LSMInvertedIndexMergeOperation mergeOp = (LSMInvertedIndexMergeOperation) operation;
+        IIndexCursor cursor = mergeOp.getCursor();
+
+        RangePredicate mergePred = new RangePredicate(null, null, true, true, null, null);
+        ILSMIndexOperationContext opCtx = ((LSMIndexSearchCursor) cursor).getOpCtx();
+        opCtx.getComponentHolder().addAll(mergeOp.getMergingComponents());
+        // Scan diskInvertedIndexes ignoring the memoryInvertedIndex.
+        search(opCtx, cursor, mergePred);
 
         // Create an inverted index instance.
-        LSMInvertedIndexImmutableComponent component = createDiskInvIndexComponent(componentFactory,
+        LSMInvertedIndexDiskComponent component = createDiskInvIndexComponent(componentFactory,
                 mergeOp.getDictBTreeMergeTarget(), mergeOp.getDeletedKeysBTreeMergeTarget(),
                 mergeOp.getBloomFilterMergeTarget(), true);
 
         IInvertedIndex mergedDiskInvertedIndex = component.getInvIndex();
-        IIndexCursor cursor = mergeOp.getCursor();
         IIndexBulkLoader invIndexBulkLoader = mergedDiskInvertedIndex.createBulkLoader(1.0f, true, 0L, false);
         try {
             while (cursor.hasNext()) {
@@ -545,10 +572,6 @@
             cursor.close();
         }
         invIndexBulkLoader.end();
-
-        // Add the merged components for cleanup.
-        mergedComponents.addAll(mergeOp.getMergingComponents());
-
         return component;
     }
 
@@ -568,10 +591,6 @@
         }
     }
 
-    public boolean isEmptyIndex() throws HyracksDataException {
-        return componentsRef.get().isEmpty() && !mutableComponent.isModified();
-    }
-
     public class LSMInvertedIndexBulkLoader implements IIndexBulkLoader {
         private final ILSMComponent component;
         private final IIndexBulkLoader invIndexBulkLoader;
@@ -590,8 +609,8 @@
             } catch (HyracksDataException | IndexException e) {
                 throw new IndexException(e);
             }
-            invIndexBulkLoader = ((LSMInvertedIndexImmutableComponent) component).getInvIndex().createBulkLoader(
-                    fillFactor, verifyInput, numElementsHint, false);
+            invIndexBulkLoader = ((LSMInvertedIndexDiskComponent) component).getInvIndex().createBulkLoader(fillFactor,
+                    verifyInput, numElementsHint, false);
         }
 
         @Override
@@ -610,12 +629,12 @@
         protected void cleanupArtifacts() throws HyracksDataException {
             if (!cleanedUpArtifacts) {
                 cleanedUpArtifacts = true;
-                ((LSMInvertedIndexImmutableComponent) component).getInvIndex().deactivate();
-                ((LSMInvertedIndexImmutableComponent) component).getInvIndex().destroy();
-                ((LSMInvertedIndexImmutableComponent) component).getDeletedKeysBTree().deactivate();
-                ((LSMInvertedIndexImmutableComponent) component).getDeletedKeysBTree().destroy();
-                ((LSMInvertedIndexImmutableComponent) component).getBloomFilter().deactivate();
-                ((LSMInvertedIndexImmutableComponent) component).getBloomFilter().destroy();
+                ((LSMInvertedIndexDiskComponent) component).getInvIndex().deactivate();
+                ((LSMInvertedIndexDiskComponent) component).getInvIndex().destroy();
+                ((LSMInvertedIndexDiskComponent) component).getDeletedKeysBTree().deactivate();
+                ((LSMInvertedIndexDiskComponent) component).getDeletedKeysBTree().destroy();
+                ((LSMInvertedIndexDiskComponent) component).getBloomFilter().deactivate();
+                ((LSMInvertedIndexDiskComponent) component).getBloomFilter().destroy();
             }
         }
 
@@ -632,17 +651,17 @@
         }
     }
 
-    protected InMemoryInvertedIndex createInMemoryInvertedIndex(IVirtualBufferCache virtualBufferCache)
-            throws IndexException {
+    protected InMemoryInvertedIndex createInMemoryInvertedIndex(IVirtualBufferCache virtualBufferCache,
+            IVirtualFreePageManager virtualFreePageManager, int id) throws IndexException {
         return InvertedIndexUtils.createInMemoryBTreeInvertedindex(virtualBufferCache, virtualFreePageManager,
                 invListTypeTraits, invListCmpFactories, tokenTypeTraits, tokenCmpFactories, tokenizerFactory,
-                new FileReference(new File(fileManager.getBaseDir() + "_virtual_vocab")));
+                new FileReference(new File(fileManager.getBaseDir() + "_virtual_vocab_" + id)));
     }
 
-    protected LSMInvertedIndexImmutableComponent createDiskInvIndexComponent(ILSMComponentFactory factory,
+    protected LSMInvertedIndexDiskComponent createDiskInvIndexComponent(ILSMComponentFactory factory,
             FileReference dictBTreeFileRef, FileReference btreeFileRef, FileReference bloomFilterFileRef, boolean create)
             throws HyracksDataException, IndexException {
-        LSMInvertedIndexImmutableComponent component = (LSMInvertedIndexImmutableComponent) factory
+        LSMInvertedIndexDiskComponent component = (LSMInvertedIndexDiskComponent) factory
                 .createLSMComponentInstance(new LSMComponentFileReferences(dictBTreeFileRef, btreeFileRef,
                         bloomFilterFileRef));
         if (create) {
@@ -659,15 +678,13 @@
 
     @Override
     public ILSMIndexAccessorInternal createAccessor(IModificationOperationCallback modificationCallback,
-            ISearchOperationCallback searchCallback) {
-        return new LSMInvertedIndexAccessor(this, lsmHarness, fileManager, createOpContext(modificationCallback,
-                searchCallback));
+            ISearchOperationCallback searchCallback) throws HyracksDataException {
+        return new LSMInvertedIndexAccessor(lsmHarness, createOpContext(modificationCallback, searchCallback));
     }
 
     private LSMInvertedIndexOpContext createOpContext(IModificationOperationCallback modificationCallback,
-            ISearchOperationCallback searchCallback) {
-        return new LSMInvertedIndexOpContext(mutableComponent.getInvIndex(), mutableComponent.getDeletedKeysBTree(),
-                modificationCallback, searchCallback);
+            ISearchOperationCallback searchCallback) throws HyracksDataException {
+        return new LSMInvertedIndexOpContext(memoryComponents, modificationCallback, searchCallback);
     }
 
     @Override
@@ -693,8 +710,13 @@
 
     @Override
     public long getMemoryAllocationSize() {
-        IBufferCache virtualBufferCache = mutableComponent.getInvIndex().getBufferCache();
-        return virtualBufferCache.getNumPages() * virtualBufferCache.getPageSize();
+        long size = 0;
+        for (ILSMComponent c : memoryComponents) {
+            LSMInvertedIndexMemoryComponent mutableComponent = (LSMInvertedIndexMemoryComponent) c;
+            IBufferCache virtualBufferCache = mutableComponent.getInvIndex().getBufferCache();
+            size += virtualBufferCache.getNumPages() * virtualBufferCache.getPageSize();
+        }
+        return size;
     }
 
     @Override
@@ -721,7 +743,7 @@
 
     @Override
     public void markAsValid(ILSMComponent lsmComponent) throws HyracksDataException {
-        LSMInvertedIndexImmutableComponent invIndexComponent = (LSMInvertedIndexImmutableComponent) lsmComponent;
+        LSMInvertedIndexDiskComponent invIndexComponent = (LSMInvertedIndexDiskComponent) lsmComponent;
         OnDiskInvertedIndex invIndex = (OnDiskInvertedIndex) invIndexComponent.getInvIndex();
         // Flush the bloom filter first.
         int fileId = invIndexComponent.getBloomFilter().getFileId();
@@ -742,11 +764,14 @@
 
     @Override
     public void validate() throws HyracksDataException {
-        mutableComponent.getInvIndex().validate();
-        mutableComponent.getDeletedKeysBTree().validate();
-        List<ILSMComponent> immutableComponents = componentsRef.get();
+        for (ILSMComponent c : memoryComponents) {
+            LSMInvertedIndexMemoryComponent mutableComponent = (LSMInvertedIndexMemoryComponent) c;
+            mutableComponent.getInvIndex().validate();
+            mutableComponent.getDeletedKeysBTree().validate();
+        }
+        List<ILSMComponent> immutableComponents = diskComponents;
         for (ILSMComponent c : immutableComponents) {
-            LSMInvertedIndexImmutableComponent component = (LSMInvertedIndexImmutableComponent) c;
+            LSMInvertedIndexDiskComponent component = (LSMInvertedIndexDiskComponent) c;
             component.getInvIndex().validate();
             component.getDeletedKeysBTree().validate();
         }
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexAccessor.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexAccessor.java
index 16f1fa1..e31af9a 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexAccessor.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexAccessor.java
@@ -25,7 +25,6 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperation;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexAccessorInternal;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexFileManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexOperationContext;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedListCursor;
@@ -33,16 +32,11 @@
 public class LSMInvertedIndexAccessor implements ILSMIndexAccessorInternal, IInvertedIndexAccessor {
 
     protected final ILSMHarness lsmHarness;
-    protected final ILSMIndexFileManager fileManager;
     protected final ILSMIndexOperationContext ctx;
-    protected final LSMInvertedIndex invIndex;
 
-    public LSMInvertedIndexAccessor(LSMInvertedIndex invIndex, ILSMHarness lsmHarness,
-            ILSMIndexFileManager fileManager, ILSMIndexOperationContext ctx) {
+    public LSMInvertedIndexAccessor(ILSMHarness lsmHarness, ILSMIndexOperationContext ctx) {
         this.lsmHarness = lsmHarness;
-        this.fileManager = fileManager;
         this.ctx = ctx;
-        this.invIndex = invIndex;
     }
 
     @Override
@@ -112,11 +106,6 @@
     }
 
     @Override
-    public void noOp() throws HyracksDataException {
-        lsmHarness.noOp(ctx);
-    }
-
-    @Override
     public void forcePhysicalDelete(ITupleReference tuple) throws HyracksDataException, IndexException {
         throw new UnsupportedOperationException("Physical delete not supported by lsm inverted index.");
     }
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexImmutableComponent.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexDiskComponent.java
similarity index 85%
rename from hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexImmutableComponent.java
rename to hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexDiskComponent.java
index 829d5d4..323edd1 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexImmutableComponent.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexDiskComponent.java
@@ -17,16 +17,16 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.am.bloomfilter.impls.BloomFilter;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.AbstractImmutableLSMComponent;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.AbstractDiskLSMComponent;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedIndex;
 
-public class LSMInvertedIndexImmutableComponent extends AbstractImmutableLSMComponent {
+public class LSMInvertedIndexDiskComponent extends AbstractDiskLSMComponent {
 
     private final IInvertedIndex invIndex;
     private final BTree deletedKeysBTree;
     private final BloomFilter bloomFilter;
 
-    public LSMInvertedIndexImmutableComponent(IInvertedIndex invIndex, BTree deletedKeysBTree, BloomFilter bloomFilter) {
+    public LSMInvertedIndexDiskComponent(IInvertedIndex invIndex, BTree deletedKeysBTree, BloomFilter bloomFilter) {
         this.invIndex = invIndex;
         this.deletedKeysBTree = deletedKeysBTree;
         this.bloomFilter = bloomFilter;
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexComponentFactory.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexDiskComponentFactory.java
similarity index 89%
rename from hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexComponentFactory.java
rename to hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexDiskComponentFactory.java
index 1455647..f83f529 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexComponentFactory.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexDiskComponentFactory.java
@@ -26,12 +26,12 @@
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.ondisk.OnDiskInvertedIndexFactory;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 
-public class LSMInvertedIndexComponentFactory implements ILSMComponentFactory {
+public class LSMInvertedIndexDiskComponentFactory implements ILSMComponentFactory {
     private final OnDiskInvertedIndexFactory diskInvIndexFactory;
     private final TreeIndexFactory<BTree> btreeFactory;
     private final BloomFilterFactory bloomFilterFactory;
 
-    public LSMInvertedIndexComponentFactory(OnDiskInvertedIndexFactory diskInvIndexFactory,
+    public LSMInvertedIndexDiskComponentFactory(OnDiskInvertedIndexFactory diskInvIndexFactory,
             TreeIndexFactory<BTree> btreeFactory, BloomFilterFactory bloomFilterFactory) {
         this.diskInvIndexFactory = diskInvIndexFactory;
         this.btreeFactory = btreeFactory;
@@ -41,7 +41,7 @@
     @Override
     public ILSMComponent createLSMComponentInstance(LSMComponentFileReferences cfr) throws IndexException,
             HyracksDataException {
-        return new LSMInvertedIndexImmutableComponent(diskInvIndexFactory.createIndexInstance(cfr
+        return new LSMInvertedIndexDiskComponent(diskInvIndexFactory.createIndexInstance(cfr
                 .getInsertIndexFileReference()), btreeFactory.createIndexInstance(cfr.getDeleteIndexFileReference()),
                 bloomFilterFactory.createBloomFiltertInstance(cfr.getBloomFilterFileReference()));
     }
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexFlushOperation.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexFlushOperation.java
index a8973d1..45433e7 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexFlushOperation.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexFlushOperation.java
@@ -23,22 +23,22 @@
 import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.api.io.IODeviceHandle;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperation;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexAccessorInternal;
 
 public class LSMInvertedIndexFlushOperation implements ILSMIOOperation {
     private final ILSMIndexAccessorInternal accessor;
-    private final LSMInvertedIndexMutableComponent flushingComponent;
+    private final ILSMComponent flushingComponent;
     private final FileReference dictBTreeFlushTarget;
     private final FileReference deletedKeysBTreeFlushTarget;
     private final FileReference bloomFilterFlushTarget;
     private final ILSMIOOperationCallback callback;
 
-    public LSMInvertedIndexFlushOperation(ILSMIndexAccessorInternal accessor,
-            LSMInvertedIndexMutableComponent flushingComponent, FileReference dictBTreeFlushTarget,
-            FileReference deletedKeysBTreeFlushTarget, FileReference bloomFilterFlushTarget,
-            ILSMIOOperationCallback callback) {
+    public LSMInvertedIndexFlushOperation(ILSMIndexAccessorInternal accessor, ILSMComponent flushingComponent,
+            FileReference dictBTreeFlushTarget, FileReference deletedKeysBTreeFlushTarget,
+            FileReference bloomFilterFlushTarget, ILSMIOOperationCallback callback) {
         this.accessor = accessor;
         this.flushingComponent = flushingComponent;
         this.dictBTreeFlushTarget = dictBTreeFlushTarget;
@@ -63,8 +63,9 @@
     }
 
     @Override
-    public void perform() throws HyracksDataException, IndexException {
+    public Boolean call() throws HyracksDataException, IndexException {
         accessor.flush(this);
+        return true;
     }
 
     @Override
@@ -84,7 +85,7 @@
         return bloomFilterFlushTarget;
     }
 
-    public LSMInvertedIndexMutableComponent getFlushingComponent() {
+    public ILSMComponent getFlushingComponent() {
         return flushingComponent;
     }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexMutableComponent.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexMemoryComponent.java
similarity index 82%
rename from hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexMutableComponent.java
rename to hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexMemoryComponent.java
index 7084803..eb1f915 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexMutableComponent.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexMemoryComponent.java
@@ -18,19 +18,19 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.AbstractMutableLSMComponent;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.AbstractMemoryLSMComponent;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedIndex;
 
-public class LSMInvertedIndexMutableComponent extends AbstractMutableLSMComponent {
+public class LSMInvertedIndexMemoryComponent extends AbstractMemoryLSMComponent {
 
     private final IInvertedIndex invIndex;
     private final BTree deletedKeysBTree;
-    private final IVirtualBufferCache vbc;
 
-    public LSMInvertedIndexMutableComponent(IInvertedIndex invIndex, BTree deletedKeysBTree, IVirtualBufferCache vbc) {
+    public LSMInvertedIndexMemoryComponent(IInvertedIndex invIndex, BTree deletedKeysBTree, IVirtualBufferCache vbc,
+            boolean isActive) {
+        super(vbc, isActive);
         this.invIndex = invIndex;
         this.deletedKeysBTree = deletedKeysBTree;
-        this.vbc = vbc;
     }
 
     public IInvertedIndex getInvIndex() {
@@ -42,11 +42,6 @@
     }
 
     @Override
-    protected boolean isFull() {
-        return vbc.isFull();
-    }
-
-    @Override
     protected void reset() throws HyracksDataException {
         super.reset();
         invIndex.deactivate();
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexMergeOperation.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexMergeOperation.java
index 7714808..7cd921a 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexMergeOperation.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexMergeOperation.java
@@ -55,7 +55,7 @@
     public Set<IODeviceHandle> getReadDevices() {
         Set<IODeviceHandle> devs = new HashSet<IODeviceHandle>();
         for (Object o : mergingComponents) {
-            LSMInvertedIndexImmutableComponent component = (LSMInvertedIndexImmutableComponent) o;
+            LSMInvertedIndexDiskComponent component = (LSMInvertedIndexDiskComponent) o;
             OnDiskInvertedIndex invIndex = (OnDiskInvertedIndex) component.getInvIndex();
             devs.add(invIndex.getBTree().getFileReference().getDeviceHandle());
             devs.add(component.getDeletedKeysBTree().getFileReference().getDeviceHandle());
@@ -74,8 +74,9 @@
     }
 
     @Override
-    public void perform() throws HyracksDataException, IndexException {
+    public Boolean call() throws HyracksDataException, IndexException {
         accessor.merge(this);
+        return true;
     }
 
     @Override
@@ -102,5 +103,4 @@
     public List<ILSMComponent> getMergingComponents() {
         return mergingComponents;
     }
-
 }
\ No newline at end of file
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexOpContext.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexOpContext.java
index fd83bfb..1a9303f 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexOpContext.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexOpContext.java
@@ -19,7 +19,6 @@
 import java.util.List;
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.storage.am.common.api.IIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.common.api.IModificationOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.api.ISearchOperationCallback;
@@ -28,7 +27,6 @@
 import edu.uci.ics.hyracks.storage.am.common.tuples.PermutingTupleReference;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexOperationContext;
-import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedIndexAccessor;
 
 public class LSMInvertedIndexOpContext implements ILSMIndexOperationContext {
@@ -36,8 +34,6 @@
     private static final int NUM_DOCUMENT_FIELDS = 1;
 
     private IndexOperation op;
-    private final IInvertedIndex memInvIndex;
-    private final IIndex memDeletedKeysBTree;
     private final List<ILSMComponent> componentHolder;
 
     public final IModificationOperationCallback modificationCallback;
@@ -46,18 +42,43 @@
     // Tuple that only has the inverted-index elements (aka keys), projecting away the document fields.
     public PermutingTupleReference keysOnlyTuple;
 
-    // Accessor to the in-memory inverted index.
-    public IInvertedIndexAccessor memInvIndexAccessor;
-    // Accessor to the deleted-keys BTree.
-    public IIndexAccessor deletedKeysBTreeAccessor;
+    // Accessor to the in-memory inverted indexes.
+    public IInvertedIndexAccessor[] mutableInvIndexAccessors;
+    // Accessor to the deleted-keys BTrees.
+    public IIndexAccessor[] deletedKeysBTreeAccessors;
 
-    public LSMInvertedIndexOpContext(IInvertedIndex memInvIndex, IIndex memDeletedKeysBTree,
-            IModificationOperationCallback modificationCallback, ISearchOperationCallback searchCallback) {
-        this.memInvIndex = memInvIndex;
-        this.memDeletedKeysBTree = memDeletedKeysBTree;
+    public IInvertedIndexAccessor currentMutableInvIndexAccessors;
+    public IIndexAccessor currentDeletedKeysBTreeAccessors;
+
+    public LSMInvertedIndexOpContext(List<ILSMComponent> mutableComponents,
+            IModificationOperationCallback modificationCallback, ISearchOperationCallback searchCallback)
+            throws HyracksDataException {
         this.componentHolder = new LinkedList<ILSMComponent>();
         this.modificationCallback = modificationCallback;
         this.searchCallback = searchCallback;
+
+        mutableInvIndexAccessors = new IInvertedIndexAccessor[mutableComponents.size()];
+        deletedKeysBTreeAccessors = new IIndexAccessor[mutableComponents.size()];
+
+        for (int i = 0; i < mutableComponents.size(); i++) {
+            LSMInvertedIndexMemoryComponent mutableComponent = (LSMInvertedIndexMemoryComponent) mutableComponents
+                    .get(i);
+            mutableInvIndexAccessors[i] = (IInvertedIndexAccessor) mutableComponent.getInvIndex().createAccessor(
+                    NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
+            deletedKeysBTreeAccessors[i] = mutableComponent.getDeletedKeysBTree().createAccessor(
+                    NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
+        }
+
+        assert mutableComponents.size() > 0;
+
+        // Project away the document fields, leaving only the key fields.
+        LSMInvertedIndexMemoryComponent c = (LSMInvertedIndexMemoryComponent) mutableComponents.get(0);
+        int numKeyFields = c.getInvIndex().getInvListTypeTraits().length;
+        int[] keyFieldPermutation = new int[numKeyFields];
+        for (int i = 0; i < numKeyFields; i++) {
+            keyFieldPermutation[i] = NUM_DOCUMENT_FIELDS + i;
+        }
+        keysOnlyTuple = new PermutingTupleReference(keyFieldPermutation);
     }
 
     @Override
@@ -69,26 +90,6 @@
     // TODO: Ignore opcallback for now.
     public void setOperation(IndexOperation newOp) throws HyracksDataException {
         reset();
-        switch (newOp) {
-            case INSERT:
-            case DELETE:
-            case PHYSICALDELETE: {
-                if (deletedKeysBTreeAccessor == null) {
-                    memInvIndexAccessor = (IInvertedIndexAccessor) memInvIndex.createAccessor(
-                            NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
-                    deletedKeysBTreeAccessor = memDeletedKeysBTree.createAccessor(NoOpOperationCallback.INSTANCE,
-                            NoOpOperationCallback.INSTANCE);
-                    // Project away the document fields, leaving only the key fields.
-                    int numKeyFields = memInvIndex.getInvListTypeTraits().length;
-                    int[] keyFieldPermutation = new int[numKeyFields];
-                    for (int i = 0; i < numKeyFields; i++) {
-                        keyFieldPermutation[i] = NUM_DOCUMENT_FIELDS + i;
-                    }
-                    keysOnlyTuple = new PermutingTupleReference(keyFieldPermutation);
-                }
-                break;
-            }
-        }
         op = newOp;
     }
 
@@ -111,4 +112,10 @@
     public IModificationOperationCallback getModificationCallback() {
         return modificationCallback;
     }
+
+    @Override
+    public void setCurrentMutableComponentId(int currentMutableComponentId) {
+        currentMutableInvIndexAccessors = mutableInvIndexAccessors[currentMutableComponentId];
+        currentDeletedKeysBTreeAccessors = deletedKeysBTreeAccessors[currentMutableComponentId];
+    }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexRangeSearchCursor.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexRangeSearchCursor.java
index 820b516..cd0dde3 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexRangeSearchCursor.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexRangeSearchCursor.java
@@ -27,7 +27,9 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
 import edu.uci.ics.hyracks.storage.am.common.tuples.PermutingTupleReference;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexOperationContext;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent.LSMComponentType;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BloomFilterAwareBTreePointSearchCursor;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMIndexSearchCursor;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedIndexAccessor;
@@ -63,7 +65,7 @@
         }
         lsmHarness = lsmInitState.getLSMHarness();
         operationalComponents = lsmInitState.getOperationalComponents();
-        includeMemComponent = lsmInitState.getIncludeMemComponent();
+        includeMutableComponent = lsmInitState.getIncludeMemComponent();
 
         // For searching the deleted-keys BTrees.
         this.keysOnlyTuple = lsmInitState.getKeysOnlyTuple();
@@ -71,18 +73,17 @@
 
         if (!deletedKeysBTreeAccessors.isEmpty()) {
             deletedKeysBTreeCursors = new IIndexCursor[deletedKeysBTreeAccessors.size()];
-            int i = 0;
-            if (includeMemComponent) {
-                // No need for a bloom filter for the in-memory BTree.
-                deletedKeysBTreeCursors[i] = deletedKeysBTreeAccessors.get(i).createSearchCursor();
-                ++i;
+            for (int i = 0; i < operationalComponents.size(); i++) {
+                ILSMComponent component = operationalComponents.get(i);
+                if (component.getType() == LSMComponentType.MEMORY) {
+                 // No need for a bloom filter for the in-memory BTree.
+                    deletedKeysBTreeCursors[i] = deletedKeysBTreeAccessors.get(i).createSearchCursor();
+                } else {
+                    deletedKeysBTreeCursors[i] = new BloomFilterAwareBTreePointSearchCursor((IBTreeLeafFrame) lsmInitState
+                            .getgetDeletedKeysBTreeLeafFrameFactory().createFrame(), false,
+                            ((LSMInvertedIndexDiskComponent) operationalComponents.get(i)).getBloomFilter());
+                }
             }
-            for (; i < deletedKeysBTreeCursors.length; i++) {
-                deletedKeysBTreeCursors[i] = new BloomFilterAwareBTreePointSearchCursor((IBTreeLeafFrame) lsmInitState
-                        .getgetDeletedKeysBTreeLeafFrameFactory().createFrame(), false,
-                        ((LSMInvertedIndexImmutableComponent) operationalComponents.get(i)).getBloomFilter());
-            }
-
         }
         MultiComparator keyCmp = lsmInitState.getKeyComparator();
         keySearchPred = new RangePredicate(keysOnlyTuple, keysOnlyTuple, true, true, keyCmp, keyCmp);
@@ -113,7 +114,7 @@
         }
         return false;
     }
-    
+
     @Override
     protected void checkPriorityQueue() throws HyracksDataException, IndexException {
         while (!outputPriorityQueue.isEmpty() || needPush == true) {
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexSearchCursor.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexSearchCursor.java
index 882d1a1..19acbfb 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexSearchCursor.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexSearchCursor.java
@@ -28,6 +28,7 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent.LSMComponentType;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMHarness;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexOperationContext;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BloomFilterAwareBTreePointSearchCursor;
@@ -44,7 +45,6 @@
     private int accessorIndex = -1;
     private boolean tupleConsumed = true;
     private ILSMHarness harness;
-    private boolean includeMemComponent;
     private List<IIndexAccessor> indexAccessors;
     private ISearchPredicate searchPred;
     private ISearchOperationCallback searchCallback;
@@ -61,7 +61,6 @@
     public void open(ICursorInitialState initialState, ISearchPredicate searchPred) throws HyracksDataException {
         LSMInvertedIndexSearchCursorInitialState lsmInitState = (LSMInvertedIndexSearchCursorInitialState) initialState;
         harness = lsmInitState.getLSMHarness();
-        includeMemComponent = lsmInitState.getIncludeMemComponent();
         operationalComponents = lsmInitState.getOperationalComponents();
         indexAccessors = lsmInitState.getIndexAccessors();
         opCtx = lsmInitState.getOpContext();
@@ -72,16 +71,17 @@
         // For searching the deleted-keys BTrees.
         deletedKeysBTreeAccessors = lsmInitState.getDeletedKeysBTreeAccessors();
         deletedKeysBTreeCursors = new IIndexCursor[deletedKeysBTreeAccessors.size()];
-        int i = 0;
-        if (includeMemComponent) {
-            // No need for a bloom filter for the in-memory BTree.
-            deletedKeysBTreeCursors[i] = deletedKeysBTreeAccessors.get(i).createSearchCursor();
-            ++i;
-        }
-        for (; i < deletedKeysBTreeCursors.length; i++) {
-            deletedKeysBTreeCursors[i] = new BloomFilterAwareBTreePointSearchCursor((IBTreeLeafFrame) lsmInitState
-                    .getgetDeletedKeysBTreeLeafFrameFactory().createFrame(), false,
-                    ((LSMInvertedIndexImmutableComponent) operationalComponents.get(i)).getBloomFilter());
+
+        for (int i = 0; i < operationalComponents.size(); i++) {
+            ILSMComponent component = operationalComponents.get(i);
+            if (component.getType() == LSMComponentType.MEMORY) {
+                // No need for a bloom filter for the in-memory BTree.
+                deletedKeysBTreeCursors[i] = deletedKeysBTreeAccessors.get(i).createSearchCursor();
+            } else {
+                deletedKeysBTreeCursors[i] = new BloomFilterAwareBTreePointSearchCursor((IBTreeLeafFrame) lsmInitState
+                        .getgetDeletedKeysBTreeLeafFrameFactory().createFrame(), false,
+                        ((LSMInvertedIndexDiskComponent) operationalComponents.get(i)).getBloomFilter());
+            }
         }
 
         MultiComparator keyCmp = lsmInitState.getKeyComparator();
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/PartitionedLSMInvertedIndex.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/PartitionedLSMInvertedIndex.java
index 185321b..ddb6060 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/PartitionedLSMInvertedIndex.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/PartitionedLSMInvertedIndex.java
@@ -16,13 +16,15 @@
 package edu.uci.ics.hyracks.storage.am.lsm.invertedindex.impls;
 
 import java.io.File;
+import java.util.List;
 
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.storage.am.bloomfilter.impls.BloomFilterFactory;
+import edu.uci.ics.hyracks.storage.am.common.api.IVirtualFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexFileManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
@@ -37,25 +39,25 @@
 
 public class PartitionedLSMInvertedIndex extends LSMInvertedIndex {
 
-    public PartitionedLSMInvertedIndex(IVirtualBufferCache virtualBufferCache,
+    public PartitionedLSMInvertedIndex(List<IVirtualBufferCache> virtualBufferCaches,
             OnDiskInvertedIndexFactory diskInvIndexFactory, BTreeFactory deletedKeysBTreeFactory,
             BloomFilterFactory bloomFilterFactory, double bloomFilterFalsePositiveRate,
             ILSMIndexFileManager fileManager, IFileMapProvider diskFileMapProvider, ITypeTraits[] invListTypeTraits,
             IBinaryComparatorFactory[] invListCmpFactories, ITypeTraits[] tokenTypeTraits,
             IBinaryComparatorFactory[] tokenCmpFactories, IBinaryTokenizerFactory tokenizerFactory,
             ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider) throws IndexException {
-        super(virtualBufferCache, diskInvIndexFactory, deletedKeysBTreeFactory, bloomFilterFactory,
+            ILSMIOOperationCallback ioOpCallback) throws IndexException {
+        super(virtualBufferCaches, diskInvIndexFactory, deletedKeysBTreeFactory, bloomFilterFactory,
                 bloomFilterFalsePositiveRate, fileManager, diskFileMapProvider, invListTypeTraits, invListCmpFactories,
-                tokenTypeTraits, tokenCmpFactories, tokenizerFactory, mergePolicy, opTracker, ioScheduler,
-                ioOpCallbackProvider);
+                tokenTypeTraits, tokenCmpFactories, tokenizerFactory, mergePolicy, opTracker, ioScheduler, ioOpCallback);
     }
 
-    protected InMemoryInvertedIndex createInMemoryInvertedIndex(IVirtualBufferCache virtualBufferCache)
-            throws IndexException {
+    @Override
+    protected InMemoryInvertedIndex createInMemoryInvertedIndex(IVirtualBufferCache virtualBufferCache,
+            IVirtualFreePageManager virtualFreePageManager, int id) throws IndexException {
         return InvertedIndexUtils.createPartitionedInMemoryBTreeInvertedindex(virtualBufferCache,
                 virtualFreePageManager, invListTypeTraits, invListCmpFactories, tokenTypeTraits, tokenCmpFactories,
-                tokenizerFactory, new FileReference(new File(fileManager.getBaseDir() + "_virtual_vocab")));
+                tokenizerFactory, new FileReference(new File(fileManager.getBaseDir() + "_virtual_vocab_" + id)));
     }
 
 }
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/inmemory/InMemoryInvertedIndex.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/inmemory/InMemoryInvertedIndex.java
index 222f4de..c70c2d5 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/inmemory/InMemoryInvertedIndex.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/inmemory/InMemoryInvertedIndex.java
@@ -19,9 +19,7 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
-import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeDuplicateKeyException;
 import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeException;
-import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeNonExistentKeyException;
 import edu.uci.ics.hyracks.storage.am.btree.frames.BTreeLeafFrameType;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree.BTreeAccessor;
@@ -33,6 +31,8 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IModificationOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.api.ISearchOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.am.common.exceptions.TreeIndexDuplicateKeyException;
+import edu.uci.ics.hyracks.storage.am.common.exceptions.TreeIndexNonExistentKeyException;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedIndex;
@@ -117,7 +117,7 @@
             ITupleReference insertTuple = ctx.tupleIter.getTuple();
             try {
                 btreeAccessor.insert(insertTuple);
-            } catch (BTreeDuplicateKeyException e) {
+            } catch (TreeIndexDuplicateKeyException e) {
                 // This exception may be caused by duplicate tokens in the same insert "document".
                 // We ignore such duplicate tokens in all inverted-index implementations, hence
                 // we can safely ignore this exception.
@@ -134,7 +134,7 @@
             ITupleReference deleteTuple = ctx.tupleIter.getTuple();
             try {
                 btreeAccessor.delete(deleteTuple);
-            } catch (BTreeNonExistentKeyException e) {
+            } catch (TreeIndexNonExistentKeyException e) {
                 // Ignore this exception, since a document may have duplicate tokens.
             }
         }
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/InvertedIndexUtils.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/InvertedIndexUtils.java
index 9d85f56..372221e 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/InvertedIndexUtils.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/InvertedIndexUtils.java
@@ -16,6 +16,7 @@
 package edu.uci.ics.hyracks.storage.am.lsm.invertedindex.util;
 
 import java.io.File;
+import java.util.List;
 
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
@@ -32,7 +33,7 @@
 import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.freepage.LinkedListFreePageManagerFactory;
 import edu.uci.ics.hyracks.storage.am.common.tuples.TypeAwareTupleWriterFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
@@ -115,13 +116,13 @@
         return deletedKeysBTreeFactory;
     }
 
-    public static LSMInvertedIndex createLSMInvertedIndex(IVirtualBufferCache virtualBufferCache,
+    public static LSMInvertedIndex createLSMInvertedIndex(List<IVirtualBufferCache> virtualBufferCaches,
             IFileMapProvider diskFileMapProvider, ITypeTraits[] invListTypeTraits,
             IBinaryComparatorFactory[] invListCmpFactories, ITypeTraits[] tokenTypeTraits,
             IBinaryComparatorFactory[] tokenCmpFactories, IBinaryTokenizerFactory tokenizerFactory,
             IBufferCache diskBufferCache, String onDiskDir, double bloomFilterFalsePositiveRate,
             ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider) throws IndexException {
+            ILSMIOOperationCallback ioOpCallback) throws IndexException {
 
         BTreeFactory deletedKeysBTreeFactory = createDeletedKeysBTreeFactory(diskFileMapProvider, invListTypeTraits,
                 invListCmpFactories, diskBufferCache);
@@ -143,20 +144,20 @@
                 diskFileMapProvider, invListBuilderFactory, invListTypeTraits, invListCmpFactories, tokenTypeTraits,
                 tokenCmpFactories, fileManager);
 
-        LSMInvertedIndex invIndex = new LSMInvertedIndex(virtualBufferCache, invIndexFactory, deletedKeysBTreeFactory,
+        LSMInvertedIndex invIndex = new LSMInvertedIndex(virtualBufferCaches, invIndexFactory, deletedKeysBTreeFactory,
                 bloomFilterFactory, bloomFilterFalsePositiveRate, fileManager, diskFileMapProvider, invListTypeTraits,
                 invListCmpFactories, tokenTypeTraits, tokenCmpFactories, tokenizerFactory, mergePolicy, opTracker,
-                ioScheduler, ioOpCallbackProvider);
+                ioScheduler, ioOpCallback);
         return invIndex;
     }
 
-    public static PartitionedLSMInvertedIndex createPartitionedLSMInvertedIndex(IVirtualBufferCache virtualBufferCache,
-            IFileMapProvider diskFileMapProvider, ITypeTraits[] invListTypeTraits,
-            IBinaryComparatorFactory[] invListCmpFactories, ITypeTraits[] tokenTypeTraits,
-            IBinaryComparatorFactory[] tokenCmpFactories, IBinaryTokenizerFactory tokenizerFactory,
-            IBufferCache diskBufferCache, String onDiskDir, double bloomFilterFalsePositiveRate,
-            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider) throws IndexException {
+    public static PartitionedLSMInvertedIndex createPartitionedLSMInvertedIndex(
+            List<IVirtualBufferCache> virtualBufferCaches, IFileMapProvider diskFileMapProvider,
+            ITypeTraits[] invListTypeTraits, IBinaryComparatorFactory[] invListCmpFactories,
+            ITypeTraits[] tokenTypeTraits, IBinaryComparatorFactory[] tokenCmpFactories,
+            IBinaryTokenizerFactory tokenizerFactory, IBufferCache diskBufferCache, String onDiskDir,
+            double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
+            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallback ioOpCallback) throws IndexException {
 
         BTreeFactory deletedKeysBTreeFactory = createDeletedKeysBTreeFactory(diskFileMapProvider, invListTypeTraits,
                 invListCmpFactories, diskBufferCache);
@@ -178,10 +179,10 @@
                 diskBufferCache, diskFileMapProvider, invListBuilderFactory, invListTypeTraits, invListCmpFactories,
                 tokenTypeTraits, tokenCmpFactories, fileManager);
 
-        PartitionedLSMInvertedIndex invIndex = new PartitionedLSMInvertedIndex(virtualBufferCache, invIndexFactory,
+        PartitionedLSMInvertedIndex invIndex = new PartitionedLSMInvertedIndex(virtualBufferCaches, invIndexFactory,
                 deletedKeysBTreeFactory, bloomFilterFactory, bloomFilterFalsePositiveRate, fileManager,
                 diskFileMapProvider, invListTypeTraits, invListCmpFactories, tokenTypeTraits, tokenCmpFactories,
-                tokenizerFactory, mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider);
+                tokenizerFactory, mergePolicy, opTracker, ioScheduler, ioOpCallback);
         return invIndex;
     }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/pom.xml b/hyracks/hyracks-storage-am-lsm-rtree/pom.xml
index 080ba68..09a7fbf 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/pom.xml
+++ b/hyracks/hyracks-storage-am-lsm-rtree/pom.xml
@@ -19,7 +19,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -39,21 +39,21 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-lsm-common</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-btree</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-rtree</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>  		
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/AbstractLSMRTreeDataflowHelper.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/AbstractLSMRTreeDataflowHelper.java
index 9fc8cea..636f0cb 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/AbstractLSMRTreeDataflowHelper.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/AbstractLSMRTreeDataflowHelper.java
@@ -15,6 +15,8 @@
 
 package edu.uci.ics.hyracks.storage.am.lsm.rtree.dataflow;
 
+import java.util.List;
+
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ILinearizeComparatorFactory;
@@ -25,7 +27,7 @@
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.AbstractTreeIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
@@ -44,25 +46,25 @@
     protected final ILinearizeComparatorFactory linearizeCmpFactory;
 
     public AbstractLSMRTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            IVirtualBufferCache virtualBufferCache, IBinaryComparatorFactory[] btreeComparatorFactories,
+            List<IVirtualBufferCache> virtualBufferCaches, IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             ILSMMergePolicy mergePolicy, ILSMOperationTrackerProvider opTrackerFactory,
-            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
+            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackFactory ioOpCallbackFactory,
             ILinearizeComparatorFactory linearizeCmpFactory) {
-        this(opDesc, ctx, partition, virtualBufferCache, DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE,
+        this(opDesc, ctx, partition, virtualBufferCaches, DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE,
                 btreeComparatorFactories, valueProviderFactories, rtreePolicyType, mergePolicy, opTrackerFactory,
-                ioScheduler, ioOpCallbackProvider, linearizeCmpFactory);
+                ioScheduler, ioOpCallbackFactory, linearizeCmpFactory);
     }
 
     public AbstractLSMRTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            IVirtualBufferCache virtualBufferCache, double bloomFilterFalsePositiveRate,
+            List<IVirtualBufferCache> virtualBufferCaches, double bloomFilterFalsePositiveRate,
             IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             ILSMMergePolicy mergePolicy, ILSMOperationTrackerProvider opTrackerFactory,
-            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
+            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackFactory ioOpCallbackFactory,
             ILinearizeComparatorFactory linearizeCmpFactory) {
-        super(opDesc, ctx, partition, virtualBufferCache, bloomFilterFalsePositiveRate, mergePolicy, opTrackerFactory,
-                ioScheduler, ioOpCallbackProvider);
+        super(opDesc, ctx, partition, virtualBufferCaches, bloomFilterFalsePositiveRate, mergePolicy, opTrackerFactory,
+                ioScheduler, ioOpCallbackFactory);
         this.btreeComparatorFactories = btreeComparatorFactories;
         this.valueProviderFactories = valueProviderFactories;
         this.rtreePolicyType = rtreePolicyType;
@@ -72,14 +74,14 @@
     @Override
     public ITreeIndex createIndexInstance() throws HyracksDataException {
         AbstractTreeIndexOperatorDescriptor treeOpDesc = (AbstractTreeIndexOperatorDescriptor) opDesc;
-        return createLSMTree(virtualBufferCache, file, opDesc.getStorageManager().getBufferCache(ctx), opDesc
+        return createLSMTree(virtualBufferCaches, file, opDesc.getStorageManager().getBufferCache(ctx), opDesc
                 .getStorageManager().getFileMapProvider(ctx), treeOpDesc.getTreeIndexTypeTraits(),
                 treeOpDesc.getTreeIndexComparatorFactories(), btreeComparatorFactories,
                 opTrackerFactory.getOperationTracker(ctx), valueProviderFactories, rtreePolicyType, linearizeCmpFactory);
 
     }
 
-    protected abstract ITreeIndex createLSMTree(IVirtualBufferCache virtualBufferCache, FileReference file,
+    protected abstract ITreeIndex createLSMTree(List<IVirtualBufferCache> virtualBufferCaches, FileReference file,
             IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ITypeTraits[] typeTraits,
             IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
             ILSMOperationTracker opTracker, IPrimitiveValueProviderFactory[] valueProviderFactories,
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelper.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelper.java
index b47bc02..92364fa 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelper.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelper.java
@@ -15,6 +15,8 @@
 
 package edu.uci.ics.hyracks.storage.am.lsm.rtree.dataflow;
 
+import java.util.List;
+
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ILinearizeComparatorFactory;
@@ -25,7 +27,7 @@
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
@@ -39,39 +41,39 @@
 public class LSMRTreeDataflowHelper extends AbstractLSMRTreeDataflowHelper {
 
     public LSMRTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            IVirtualBufferCache virtualBufferCache, IBinaryComparatorFactory[] btreeComparatorFactories,
+            List<IVirtualBufferCache> virtualBufferCaches, IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             ILSMMergePolicy mergePolicy, ILSMOperationTrackerProvider opTrackerFactory,
-            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
+            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackFactory ioOpCallbackFactory,
             ILinearizeComparatorFactory linearizeCmpFactory) {
-        super(opDesc, ctx, partition, virtualBufferCache, btreeComparatorFactories, valueProviderFactories,
-                rtreePolicyType, mergePolicy, opTrackerFactory, ioScheduler, ioOpCallbackProvider, linearizeCmpFactory);
+        super(opDesc, ctx, partition, virtualBufferCaches, btreeComparatorFactories, valueProviderFactories,
+                rtreePolicyType, mergePolicy, opTrackerFactory, ioScheduler, ioOpCallbackFactory, linearizeCmpFactory);
     }
 
     public LSMRTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            IVirtualBufferCache virtualBufferCache, double bloomFilterFalsePositiveRate,
+            List<IVirtualBufferCache> virtualBufferCaches, double bloomFilterFalsePositiveRate,
             IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             ILSMMergePolicy mergePolicy, ILSMOperationTrackerProvider opTrackerFactory,
-            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
+            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackFactory ioOpCallbackFactory,
             ILinearizeComparatorFactory linearizeCmpFactory) {
-        super(opDesc, ctx, partition, virtualBufferCache, bloomFilterFalsePositiveRate, btreeComparatorFactories,
+        super(opDesc, ctx, partition, virtualBufferCaches, bloomFilterFalsePositiveRate, btreeComparatorFactories,
                 valueProviderFactories, rtreePolicyType, mergePolicy, opTrackerFactory, ioScheduler,
-                ioOpCallbackProvider, linearizeCmpFactory);
+                ioOpCallbackFactory, linearizeCmpFactory);
     }
 
     @Override
-    protected ITreeIndex createLSMTree(IVirtualBufferCache virtualBufferCache, FileReference file,
+    protected ITreeIndex createLSMTree(List<IVirtualBufferCache> virtualBufferCaches, FileReference file,
             IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ITypeTraits[] typeTraits,
             IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
             ILSMOperationTracker opTracker, IPrimitiveValueProviderFactory[] valueProviderFactories,
             RTreePolicyType rtreePolicyType, ILinearizeComparatorFactory linearizeCmpFactory)
             throws HyracksDataException {
         try {
-            return LSMRTreeUtils.createLSMTree(virtualBufferCache, file, diskBufferCache, diskFileMapProvider,
+            return LSMRTreeUtils.createLSMTree(virtualBufferCaches, file, diskBufferCache, diskFileMapProvider,
                     typeTraits, rtreeCmpFactories, btreeCmpFactories, valueProviderFactories, rtreePolicyType,
-                    bloomFilterFalsePositiveRate, mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider,
-                    linearizeCmpFactory);
+                    bloomFilterFalsePositiveRate, mergePolicy, opTracker, ioScheduler,
+                    ioOpCallbackFactory.createIOOperationCallback(), linearizeCmpFactory);
         } catch (TreeIndexException e) {
             throw new HyracksDataException(e);
         }
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelperFactory.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelperFactory.java
index 5d35bc5..8254689 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelperFactory.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelperFactory.java
@@ -21,7 +21,7 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IndexDataflowHelper;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
@@ -42,10 +42,10 @@
             RTreePolicyType rtreePolicyType, IBinaryComparatorFactory[] btreeComparatorFactories,
             IVirtualBufferCacheProvider virtualBufferCacheProvider, ILSMMergePolicyProvider mergePolicyProvider,
             ILSMOperationTrackerProvider opTrackerFactory, ILSMIOOperationSchedulerProvider ioSchedulerProvider,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider, ILinearizeComparatorFactory linearizeCmpFactory,
+            ILSMIOOperationCallbackFactory ioOpCallbackFactory, ILinearizeComparatorFactory linearizeCmpFactory,
             double bloomFilterFalsePositiveRate) {
         super(virtualBufferCacheProvider, mergePolicyProvider, opTrackerFactory, ioSchedulerProvider,
-                ioOpCallbackProvider, bloomFilterFalsePositiveRate);
+                ioOpCallbackFactory, bloomFilterFalsePositiveRate);
         this.btreeComparatorFactories = btreeComparatorFactories;
         this.valueProviderFactories = valueProviderFactories;
         this.rtreePolicyType = rtreePolicyType;
@@ -56,9 +56,9 @@
     public IndexDataflowHelper createIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
             int partition) {
         return new LSMRTreeDataflowHelper(opDesc, ctx, partition,
-                virtualBufferCacheProvider.getVirtualBufferCache(ctx), bloomFilterFalsePositiveRate,
+                virtualBufferCacheProvider.getVirtualBufferCaches(ctx), bloomFilterFalsePositiveRate,
                 btreeComparatorFactories, valueProviderFactories, rtreePolicyType,
                 mergePolicyProvider.getMergePolicy(ctx), opTrackerFactory, ioSchedulerProvider.getIOScheduler(ctx),
-                ioOpCallbackProvider, linearizeCmpFactory);
+                ioOpCallbackFactory, linearizeCmpFactory);
     }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelper.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelper.java
index ea1b1e2..f430456 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelper.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelper.java
@@ -15,6 +15,8 @@
 
 package edu.uci.ics.hyracks.storage.am.lsm.rtree.dataflow;
 
+import java.util.List;
+
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ILinearizeComparatorFactory;
@@ -25,7 +27,7 @@
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
@@ -38,26 +40,28 @@
 
 public class LSMRTreeWithAntiMatterTuplesDataflowHelper extends AbstractLSMRTreeDataflowHelper {
     public LSMRTreeWithAntiMatterTuplesDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
-            int partition, IVirtualBufferCache virtualBufferCache, IBinaryComparatorFactory[] btreeComparatorFactories,
+            int partition, List<IVirtualBufferCache> virtualBufferCaches,
+            IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             ILSMMergePolicy mergePolicy, ILSMOperationTrackerProvider opTrackerFactory,
-            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
+            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackFactory ioOpCallbackFactory,
             ILinearizeComparatorFactory linearizeCmpFactory) {
-        super(opDesc, ctx, partition, virtualBufferCache, btreeComparatorFactories, valueProviderFactories,
-                rtreePolicyType, mergePolicy, opTrackerFactory, ioScheduler, ioOpCallbackProvider, linearizeCmpFactory);
+        super(opDesc, ctx, partition, virtualBufferCaches, btreeComparatorFactories, valueProviderFactories,
+                rtreePolicyType, mergePolicy, opTrackerFactory, ioScheduler, ioOpCallbackFactory, linearizeCmpFactory);
     }
 
     @Override
-    protected ITreeIndex createLSMTree(IVirtualBufferCache virtualBufferCache, FileReference file,
+    protected ITreeIndex createLSMTree(List<IVirtualBufferCache> virtualBufferCaches, FileReference file,
             IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ITypeTraits[] typeTraits,
             IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
             ILSMOperationTracker opTracker, IPrimitiveValueProviderFactory[] valueProviderFactories,
             RTreePolicyType rtreePolicyType, ILinearizeComparatorFactory linearizeCmpFactory)
             throws HyracksDataException {
         try {
-            return LSMRTreeUtils.createLSMTreeWithAntiMatterTuples(virtualBufferCache, file, diskBufferCache,
+            return LSMRTreeUtils.createLSMTreeWithAntiMatterTuples(virtualBufferCaches, file, diskBufferCache,
                     diskFileMapProvider, typeTraits, rtreeCmpFactories, btreeCmpFactories, valueProviderFactories,
-                    rtreePolicyType, mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider, linearizeCmpFactory);
+                    rtreePolicyType, mergePolicy, opTracker, ioScheduler,
+                    ioOpCallbackFactory.createIOOperationCallback(), linearizeCmpFactory);
         } catch (TreeIndexException e) {
             throw new HyracksDataException(e);
         }
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelperFactory.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelperFactory.java
index 5fca08f..ef34876 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelperFactory.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelperFactory.java
@@ -22,7 +22,7 @@
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexDataflowHelperFactory;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IndexDataflowHelper;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
@@ -40,14 +40,14 @@
     private final ILSMMergePolicyProvider mergePolicyProvider;
     private final ILSMOperationTrackerProvider opTrackerProvider;
     private final ILSMIOOperationSchedulerProvider ioSchedulerProvider;
-    private final ILSMIOOperationCallbackProvider ioOpCallbackProvider;
+    private final ILSMIOOperationCallbackFactory ioOpCallbackFactory;
     private final ILinearizeComparatorFactory linearizeCmpFactory;
 
     public LSMRTreeWithAntiMatterTuplesDataflowHelperFactory(IPrimitiveValueProviderFactory[] valueProviderFactories,
             RTreePolicyType rtreePolicyType, IBinaryComparatorFactory[] btreeComparatorFactories,
             IVirtualBufferCacheProvider virtualBufferCacheProvider, ILSMMergePolicyProvider mergePolicyProvider,
             ILSMOperationTrackerProvider opTrackerProvider, ILSMIOOperationSchedulerProvider ioSchedulerProvider,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider, ILinearizeComparatorFactory linearizeCmpFactory) {
+            ILSMIOOperationCallbackFactory ioOpCallbackFactory, ILinearizeComparatorFactory linearizeCmpFactory) {
         this.virtualBufferCacheProvider = virtualBufferCacheProvider;
         this.btreeComparatorFactories = btreeComparatorFactories;
         this.valueProviderFactories = valueProviderFactories;
@@ -55,7 +55,7 @@
         this.mergePolicyProvider = mergePolicyProvider;
         this.ioSchedulerProvider = ioSchedulerProvider;
         this.opTrackerProvider = opTrackerProvider;
-        this.ioOpCallbackProvider = ioOpCallbackProvider;
+        this.ioOpCallbackFactory = ioOpCallbackFactory;
         this.linearizeCmpFactory = linearizeCmpFactory;
     }
 
@@ -63,8 +63,8 @@
     public IndexDataflowHelper createIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
             int partition) {
         return new LSMRTreeWithAntiMatterTuplesDataflowHelper(opDesc, ctx, partition,
-                virtualBufferCacheProvider.getVirtualBufferCache(ctx), btreeComparatorFactories,
+                virtualBufferCacheProvider.getVirtualBufferCaches(ctx), btreeComparatorFactories,
                 valueProviderFactories, rtreePolicyType, mergePolicyProvider.getMergePolicy(ctx), opTrackerProvider,
-                ioSchedulerProvider.getIOScheduler(ctx), ioOpCallbackProvider, linearizeCmpFactory);
+                ioSchedulerProvider.getIOScheduler(ctx), ioOpCallbackFactory, linearizeCmpFactory);
     }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/AbstractLSMRTree.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/AbstractLSMRTree.java
index e3e690b..b09e115 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/AbstractLSMRTree.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/AbstractLSMRTree.java
@@ -23,24 +23,24 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
-import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeDuplicateKeyException;
-import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeNonExistentKeyException;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
-import edu.uci.ics.hyracks.storage.am.btree.impls.BTree.BTreeAccessor;
 import edu.uci.ics.hyracks.storage.am.btree.impls.RangePredicate;
 import edu.uci.ics.hyracks.storage.am.common.api.IFreePageManager;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexCursor;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexOperationContext;
 import edu.uci.ics.hyracks.storage.am.common.api.IModificationOperationCallback;
+import edu.uci.ics.hyracks.storage.am.common.api.ISearchPredicate;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexCursor;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrameFactory;
-import edu.uci.ics.hyracks.storage.am.common.api.IVirtualFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.am.common.exceptions.TreeIndexDuplicateKeyException;
+import edu.uci.ics.hyracks.storage.am.common.exceptions.TreeIndexNonExistentKeyException;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponentFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexFileManager;
@@ -52,11 +52,9 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.AbstractLSMIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BlockingIOOperationCallbackWrapper;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMComponentFileReferences;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.TreeIndexFactory;
 import edu.uci.ics.hyracks.storage.am.rtree.api.IRTreeInteriorFrame;
 import edu.uci.ics.hyracks.storage.am.rtree.api.IRTreeLeafFrame;
 import edu.uci.ics.hyracks.storage.am.rtree.impls.RTree;
-import edu.uci.ics.hyracks.storage.am.rtree.impls.RTree.RTreeAccessor;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
 
@@ -66,11 +64,6 @@
     protected final int[] comparatorFields;
     protected final IBinaryComparatorFactory[] linearizerArray;
 
-    // In-memory components.
-    protected final LSMRTreeMutableComponent mutableComponent;
-    protected final IVirtualBufferCache virtualBufferCache;
-    protected final IVirtualFreePageManager virtualFreePageManager;
-
     protected TreeTupleSorter rTreeTupleSorter;
 
     // On-disk components.
@@ -86,27 +79,35 @@
     protected final ITreeIndexFrameFactory rtreeLeafFrameFactory;
     protected final ITreeIndexFrameFactory btreeLeafFrameFactory;
 
-    public AbstractLSMRTree(IVirtualBufferCache virtualBufferCache, ITreeIndexFrameFactory rtreeInteriorFrameFactory,
-            ITreeIndexFrameFactory rtreeLeafFrameFactory, ITreeIndexFrameFactory btreeInteriorFrameFactory,
-            ITreeIndexFrameFactory btreeLeafFrameFactory, ILSMIndexFileManager fileManager,
-            TreeIndexFactory<RTree> diskRTreeFactory, ILSMComponentFactory componentFactory,
+    public AbstractLSMRTree(List<IVirtualBufferCache> virtualBufferCaches,
+            ITreeIndexFrameFactory rtreeInteriorFrameFactory, ITreeIndexFrameFactory rtreeLeafFrameFactory,
+            ITreeIndexFrameFactory btreeInteriorFrameFactory, ITreeIndexFrameFactory btreeLeafFrameFactory,
+            ILSMIndexFileManager fileManager, ILSMComponentFactory componentFactory,
             IFileMapProvider diskFileMapProvider, int fieldCount, IBinaryComparatorFactory[] rtreeCmpFactories,
             IBinaryComparatorFactory[] btreeCmpFactories, ILinearizeComparatorFactory linearizer,
             int[] comparatorFields, IBinaryComparatorFactory[] linearizerArray, double bloomFilterFalsePositiveRate,
             ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        super(virtualBufferCache, diskRTreeFactory.getBufferCache(), fileManager, diskFileMapProvider,
-                bloomFilterFalsePositiveRate, mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider);
-        virtualFreePageManager = new VirtualFreePageManager(virtualBufferCache.getNumPages());
-        RTree memRTree = new RTree(virtualBufferCache, ((IVirtualBufferCache) virtualBufferCache).getFileMapProvider(),
-                virtualFreePageManager, rtreeInteriorFrameFactory, rtreeLeafFrameFactory, rtreeCmpFactories,
-                fieldCount, new FileReference(new File(fileManager.getBaseDir() + "_virtual_r")));
-        BTree memBTree = new BTree(virtualBufferCache, ((IVirtualBufferCache) virtualBufferCache).getFileMapProvider(),
-                new VirtualFreePageManager(virtualBufferCache.getNumPages()), btreeInteriorFrameFactory,
-                btreeLeafFrameFactory, btreeCmpFactories, fieldCount, new FileReference(new File(
-                        fileManager.getBaseDir() + "_virtual_b")));
-        mutableComponent = new LSMRTreeMutableComponent(memRTree, memBTree, virtualBufferCache);
-        this.virtualBufferCache = virtualBufferCache;
+            ILSMIOOperationCallback ioOpCallback) {
+        super(virtualBufferCaches, componentFactory.getBufferCache(), fileManager, diskFileMapProvider,
+                bloomFilterFalsePositiveRate, mergePolicy, opTracker, ioScheduler, ioOpCallback);
+        int i = 0;
+        for (IVirtualBufferCache virtualBufferCache : virtualBufferCaches) {
+            RTree memRTree = new RTree(virtualBufferCache,
+                    ((IVirtualBufferCache) virtualBufferCache).getFileMapProvider(), new VirtualFreePageManager(
+                            virtualBufferCache.getNumPages()), rtreeInteriorFrameFactory, rtreeLeafFrameFactory,
+                    rtreeCmpFactories, fieldCount, new FileReference(new File(fileManager.getBaseDir() + "_virtual_r_"
+                            + i)));
+            BTree memBTree = new BTree(virtualBufferCache,
+                    ((IVirtualBufferCache) virtualBufferCache).getFileMapProvider(), new VirtualFreePageManager(
+                            virtualBufferCache.getNumPages()), btreeInteriorFrameFactory, btreeLeafFrameFactory,
+                    btreeCmpFactories, fieldCount, new FileReference(new File(fileManager.getBaseDir() + "_virtual_b_"
+                            + i)));
+            LSMRTreeMemoryComponent mutableComponent = new LSMRTreeMemoryComponent(memRTree, memBTree,
+                    virtualBufferCache, i == 0 ? true : false);
+            memoryComponents.add(mutableComponent);
+            ++i;
+        }
+
         this.rtreeInteriorFrameFactory = rtreeInteriorFrameFactory;
         this.rtreeLeafFrameFactory = rtreeLeafFrameFactory;
         this.btreeInteriorFrameFactory = btreeInteriorFrameFactory;
@@ -128,7 +129,7 @@
 
         fileManager.deleteDirs();
         fileManager.createDirs();
-        componentsRef.get().clear();
+        diskComponents.clear();
     }
 
     @Override
@@ -137,11 +138,14 @@
             throw new HyracksDataException("Failed to activate the index since it is already activated.");
         }
 
-        ((IVirtualBufferCache) mutableComponent.getRTree().getBufferCache()).open();
-        mutableComponent.getRTree().create();
-        mutableComponent.getBTree().create();
-        mutableComponent.getRTree().activate();
-        mutableComponent.getBTree().activate();
+        for (ILSMComponent c : memoryComponents) {
+            LSMRTreeMemoryComponent mutableComponent = (LSMRTreeMemoryComponent) c;
+            ((IVirtualBufferCache) mutableComponent.getRTree().getBufferCache()).open();
+            mutableComponent.getRTree().create();
+            mutableComponent.getBTree().create();
+            mutableComponent.getRTree().activate();
+            mutableComponent.getBTree().activate();
+        }
     }
 
     @Override
@@ -152,9 +156,8 @@
 
         if (flushOnExit) {
             BlockingIOOperationCallbackWrapper cb = new BlockingIOOperationCallbackWrapper(
-                    ioOpCallbackProvider.getIOOperationCallback(this));
-            ILSMIndexAccessor accessor = (ILSMIndexAccessor) createAccessor(NoOpOperationCallback.INSTANCE,
-                    NoOpOperationCallback.INSTANCE);
+                    ioOpCallback);
+            ILSMIndexAccessor accessor = createAccessor(NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
             accessor.scheduleFlush(cb);
             try {
                 cb.waitForIO();
@@ -163,11 +166,14 @@
             }
         }
 
-        mutableComponent.getRTree().deactivate();
-        mutableComponent.getBTree().deactivate();
-        mutableComponent.getRTree().destroy();
-        mutableComponent.getBTree().destroy();
-        ((IVirtualBufferCache) mutableComponent.getRTree().getBufferCache()).close();
+        for (ILSMComponent c : memoryComponents) {
+            LSMRTreeMemoryComponent mutableComponent = (LSMRTreeMemoryComponent) c;
+            mutableComponent.getRTree().deactivate();
+            mutableComponent.getBTree().deactivate();
+            mutableComponent.getRTree().destroy();
+            mutableComponent.getBTree().destroy();
+            ((IVirtualBufferCache) mutableComponent.getRTree().getBufferCache()).close();
+        }
     }
 
     @Override
@@ -183,24 +189,39 @@
             throw new HyracksDataException("Failed to clear the index since it is not activated.");
         }
 
-        mutableComponent.getRTree().clear();
-        mutableComponent.getBTree().clear();
-        mutableComponent.reset();
+        for (ILSMComponent c : memoryComponents) {
+            LSMRTreeMemoryComponent mutableComponent = (LSMRTreeMemoryComponent) c;
+            mutableComponent.getRTree().clear();
+            mutableComponent.getBTree().clear();
+            mutableComponent.reset();
+        }
     }
 
     @Override
     public void getOperationalComponents(ILSMIndexOperationContext ctx) {
         List<ILSMComponent> operationalComponents = ctx.getComponentHolder();
         operationalComponents.clear();
-        List<ILSMComponent> immutableComponents = componentsRef.get();
+        List<ILSMComponent> immutableComponents = diskComponents;
+        int cmc = currentMutableComponentId.get();
+        ctx.setCurrentMutableComponentId(cmc);
+        int numMutableComponents = memoryComponents.size();
         switch (ctx.getOperation()) {
             case INSERT:
             case DELETE:
             case FLUSH:
-                operationalComponents.add(mutableComponent);
+                operationalComponents.add(memoryComponents.get(cmc));
                 break;
             case SEARCH:
-                operationalComponents.add(mutableComponent);
+                for (int i = 0; i < numMutableComponents - 1; i++) {
+                    ILSMComponent c = memoryComponents.get((cmc + i + 1) % numMutableComponents);
+                    LSMRTreeMemoryComponent mutableComponent = (LSMRTreeMemoryComponent) c;
+                    if (mutableComponent.isReadable()) {
+                        // Make sure newest components are added first
+                        operationalComponents.add(0, mutableComponent);
+                    }
+                }
+                // The current mutable component is always added
+                operationalComponents.add(0, memoryComponents.get(cmc));
                 operationalComponents.addAll(immutableComponents);
                 break;
             case MERGE:
@@ -211,10 +232,23 @@
         }
     }
 
+    @Override
+    public void search(ILSMIndexOperationContext ictx, IIndexCursor cursor, ISearchPredicate pred)
+            throws HyracksDataException, IndexException {
+        LSMRTreeOpContext ctx = (LSMRTreeOpContext) ictx;
+        List<ILSMComponent> operationalComponents = ictx.getComponentHolder();
+
+        LSMRTreeCursorInitialState initialState = new LSMRTreeCursorInitialState(rtreeLeafFrameFactory,
+                rtreeInteriorFrameFactory, btreeLeafFrameFactory, ctx.getBTreeMultiComparator(), lsmHarness,
+                comparatorFields, linearizerArray, ctx.searchCallback, operationalComponents);
+
+        cursor.open(initialState, pred);
+    }
+
     protected LSMComponentFileReferences getMergeTargetFileName(List<ILSMComponent> mergingDiskComponents)
             throws HyracksDataException {
-        RTree firstTree = ((LSMRTreeImmutableComponent) mergingDiskComponents.get(0)).getRTree();
-        RTree lastTree = ((LSMRTreeImmutableComponent) mergingDiskComponents.get(mergingDiskComponents.size() - 1))
+        RTree firstTree = ((LSMRTreeDiskComponent) mergingDiskComponents.get(0)).getRTree();
+        RTree lastTree = ((LSMRTreeDiskComponent) mergingDiskComponents.get(mergingDiskComponents.size() - 1))
                 .getRTree();
         FileReference firstFile = diskFileMapProvider.lookupFileName(firstTree.getFileId());
         FileReference lastFile = diskFileMapProvider.lookupFileName(lastTree.getFileId());
@@ -223,11 +257,11 @@
         return fileRefs;
     }
 
-    protected LSMRTreeImmutableComponent createDiskComponent(ILSMComponentFactory factory, FileReference insertFileRef,
+    protected LSMRTreeDiskComponent createDiskComponent(ILSMComponentFactory factory, FileReference insertFileRef,
             FileReference deleteFileRef, FileReference bloomFilterFileRef, boolean createComponent)
             throws HyracksDataException, IndexException {
         // Create new tree instance.
-        LSMRTreeImmutableComponent component = (LSMRTreeImmutableComponent) factory
+        LSMRTreeDiskComponent component = (LSMRTreeDiskComponent) factory
                 .createLSMComponentInstance(new LSMComponentFileReferences(insertFileRef, deleteFileRef,
                         bloomFilterFileRef));
         if (createComponent) {
@@ -248,31 +282,43 @@
 
     @Override
     public ITreeIndexFrameFactory getLeafFrameFactory() {
+        LSMRTreeMemoryComponent mutableComponent = (LSMRTreeMemoryComponent) memoryComponents
+                .get(currentMutableComponentId.get());
         return mutableComponent.getRTree().getLeafFrameFactory();
     }
 
     @Override
     public ITreeIndexFrameFactory getInteriorFrameFactory() {
+        LSMRTreeMemoryComponent mutableComponent = (LSMRTreeMemoryComponent) memoryComponents
+                .get(currentMutableComponentId.get());
         return mutableComponent.getRTree().getInteriorFrameFactory();
     }
 
     @Override
     public IFreePageManager getFreePageManager() {
+        LSMRTreeMemoryComponent mutableComponent = (LSMRTreeMemoryComponent) memoryComponents
+                .get(currentMutableComponentId.get());
         return mutableComponent.getRTree().getFreePageManager();
     }
 
     @Override
     public int getFieldCount() {
+        LSMRTreeMemoryComponent mutableComponent = (LSMRTreeMemoryComponent) memoryComponents
+                .get(currentMutableComponentId.get());
         return mutableComponent.getRTree().getFieldCount();
     }
 
     @Override
     public int getRootPageId() {
+        LSMRTreeMemoryComponent mutableComponent = (LSMRTreeMemoryComponent) memoryComponents
+                .get(currentMutableComponentId.get());
         return mutableComponent.getRTree().getRootPageId();
     }
 
     @Override
     public int getFileId() {
+        LSMRTreeMemoryComponent mutableComponent = (LSMRTreeMemoryComponent) memoryComponents
+                .get(currentMutableComponentId.get());
         return mutableComponent.getRTree().getFileId();
     }
 
@@ -293,8 +339,8 @@
             // added RTree tuple.
             RangePredicate btreeRangePredicate = new RangePredicate(tuple, tuple, true, true,
                     ctx.getBTreeMultiComparator(), ctx.getBTreeMultiComparator());
-            ITreeIndexCursor cursor = ctx.memBTreeAccessor.createSearchCursor();
-            ctx.memBTreeAccessor.search(cursor, btreeRangePredicate);
+            ITreeIndexCursor cursor = ctx.currentMutableBTreeAccessor.createSearchCursor();
+            ctx.currentMutableBTreeAccessor.search(cursor, btreeRangePredicate);
             boolean foundTupleInMemoryBTree = false;
             try {
                 if (cursor.hasNext()) {
@@ -305,8 +351,8 @@
             }
             if (foundTupleInMemoryBTree) {
                 try {
-                    ctx.memBTreeAccessor.delete(tuple);
-                } catch (BTreeNonExistentKeyException e) {
+                    ctx.currentMutableBTreeAccessor.delete(tuple);
+                } catch (TreeIndexNonExistentKeyException e) {
                     // Tuple has been deleted in the meantime. Do nothing.
                     // This normally shouldn't happen if we are dealing with
                     // good citizens since LSMRTree is used as a secondary
@@ -314,31 +360,24 @@
                     // insert between them.
                 }
             } else {
-                ctx.memRTreeAccessor.insert(tuple);
+                ctx.currentMutableRTreeAccessor.insert(tuple);
             }
 
         } else {
             try {
-                ctx.memBTreeAccessor.insert(tuple);
-            } catch (BTreeDuplicateKeyException e) {
+                ctx.currentMutableBTreeAccessor.insert(tuple);
+            } catch (TreeIndexDuplicateKeyException e) {
                 // Do nothing, because one delete tuple is enough to indicate
                 // that all the corresponding insert tuples are deleted
             }
         }
-        mutableComponent.setIsModified();
     }
 
     protected LSMRTreeOpContext createOpContext(IModificationOperationCallback modCallback) {
-        RTreeAccessor rtreeAccessor = (RTree.RTreeAccessor) mutableComponent.getRTree().createAccessor(
-                NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
-        BTreeAccessor btreeAccessor = (BTree.BTreeAccessor) mutableComponent.getBTree().createAccessor(
-                NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
-
-        return new LSMRTreeOpContext(rtreeAccessor, (IRTreeLeafFrame) rtreeLeafFrameFactory.createFrame(),
-                (IRTreeInteriorFrame) rtreeInteriorFrameFactory.createFrame(), virtualFreePageManager
-                        .getMetaDataFrameFactory().createFrame(), 4, btreeAccessor, btreeLeafFrameFactory,
-                btreeInteriorFrameFactory, virtualFreePageManager.getMetaDataFrameFactory().createFrame(),
-                rtreeCmpFactories, btreeCmpFactories, modCallback, NoOpOperationCallback.INSTANCE);
+        return new LSMRTreeOpContext(memoryComponents, (IRTreeLeafFrame) rtreeLeafFrameFactory.createFrame(),
+                (IRTreeInteriorFrame) rtreeInteriorFrameFactory.createFrame(), btreeLeafFrameFactory,
+                btreeInteriorFrameFactory, rtreeCmpFactories, btreeCmpFactories, modCallback,
+                NoOpOperationCallback.INSTANCE);
     }
 
     @Override
@@ -346,10 +385,6 @@
         return rtreeCmpFactories;
     }
 
-    public boolean isEmptyIndex() throws HyracksDataException {
-        return componentsRef.get().isEmpty() && !mutableComponent.isModified();
-    }
-
     @Override
     public void validate() throws HyracksDataException {
         throw new UnsupportedOperationException("Validation not implemented for LSM R-Trees.");
@@ -357,8 +392,13 @@
 
     @Override
     public long getMemoryAllocationSize() {
-        IBufferCache virtualBufferCache = mutableComponent.getRTree().getBufferCache();
-        return virtualBufferCache.getNumPages() * virtualBufferCache.getPageSize();
+        long size = 0;
+        for (ILSMComponent c : memoryComponents) {
+            LSMRTreeMemoryComponent mutableComponent = (LSMRTreeMemoryComponent) c;
+            IBufferCache virtualBufferCache = mutableComponent.getRTree().getBufferCache();
+            size += virtualBufferCache.getNumPages() * virtualBufferCache.getPageSize();
+        }
+        return size;
     }
 
     @Override
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTree.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTree.java
index 0b71373..a4b6139 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTree.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTree.java
@@ -16,7 +16,6 @@
 package edu.uci.ics.hyracks.storage.am.lsm.rtree.impls;
 
 import java.util.List;
-import java.util.ListIterator;
 
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ILinearizeComparatorFactory;
@@ -66,7 +65,7 @@
 
 public class LSMRTree extends AbstractLSMRTree {
 
-    public LSMRTree(IVirtualBufferCache virtualBufferCache, ITreeIndexFrameFactory rtreeInteriorFrameFactory,
+    public LSMRTree(List<IVirtualBufferCache> virtualBufferCaches, ITreeIndexFrameFactory rtreeInteriorFrameFactory,
             ITreeIndexFrameFactory rtreeLeafFrameFactory, ITreeIndexFrameFactory btreeInteriorFrameFactory,
             ITreeIndexFrameFactory btreeLeafFrameFactory, ILSMIndexFileManager fileNameManager,
             TreeIndexFactory<RTree> diskRTreeFactory, TreeIndexFactory<BTree> diskBTreeFactory,
@@ -75,12 +74,12 @@
             IBinaryComparatorFactory[] btreeCmpFactories, ILinearizeComparatorFactory linearizer,
             int[] comparatorFields, IBinaryComparatorFactory[] linearizerArray, ILSMMergePolicy mergePolicy,
             ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        super(virtualBufferCache, rtreeInteriorFrameFactory, rtreeLeafFrameFactory, btreeInteriorFrameFactory,
-                btreeLeafFrameFactory, fileNameManager, diskRTreeFactory, new LSMRTreeComponentFactory(
-                        diskRTreeFactory, diskBTreeFactory, bloomFilterFactory), diskFileMapProvider, fieldCount,
-                rtreeCmpFactories, btreeCmpFactories, linearizer, comparatorFields, linearizerArray,
-                bloomFilterFalsePositiveRate, mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider);
+            ILSMIOOperationCallback ioOpCallback) {
+        super(virtualBufferCaches, rtreeInteriorFrameFactory, rtreeLeafFrameFactory, btreeInteriorFrameFactory,
+                btreeLeafFrameFactory, fileNameManager, new LSMRTreeDiskComponentFactory(diskRTreeFactory,
+                        diskBTreeFactory, bloomFilterFactory), diskFileMapProvider, fieldCount, rtreeCmpFactories,
+                btreeCmpFactories, linearizer, comparatorFields, linearizerArray, bloomFilterFalsePositiveRate,
+                mergePolicy, opTracker, ioScheduler, ioOpCallback);
     }
 
     /**
@@ -94,7 +93,7 @@
     @Override
     public synchronized void activate() throws HyracksDataException {
         super.activate();
-        List<ILSMComponent> immutableComponents = componentsRef.get();
+        List<ILSMComponent> immutableComponents = diskComponents;
         List<LSMComponentFileReferences> validFileReferences;
         try {
             validFileReferences = fileManager.cleanupAndGetValidFiles();
@@ -103,7 +102,7 @@
         }
         immutableComponents.clear();
         for (LSMComponentFileReferences lsmComonentFileReference : validFileReferences) {
-            LSMRTreeImmutableComponent component;
+            LSMRTreeDiskComponent component;
             try {
                 component = createDiskComponent(componentFactory,
                         lsmComonentFileReference.getInsertIndexFileReference(),
@@ -120,9 +119,9 @@
     @Override
     public synchronized void deactivate(boolean flushOnExit) throws HyracksDataException {
         super.deactivate(flushOnExit);
-        List<ILSMComponent> immutableComponents = componentsRef.get();
+        List<ILSMComponent> immutableComponents = diskComponents;
         for (ILSMComponent c : immutableComponents) {
-            LSMRTreeImmutableComponent component = (LSMRTreeImmutableComponent) c;
+            LSMRTreeDiskComponent component = (LSMRTreeDiskComponent) c;
             RTree rtree = component.getRTree();
             BTree btree = component.getBTree();
             BloomFilter bloomFilter = component.getBloomFilter();
@@ -141,9 +140,9 @@
     @Override
     public synchronized void destroy() throws HyracksDataException {
         super.destroy();
-        List<ILSMComponent> immutableComponents = componentsRef.get();
+        List<ILSMComponent> immutableComponents = diskComponents;
         for (ILSMComponent c : immutableComponents) {
-            LSMRTreeImmutableComponent component = (LSMRTreeImmutableComponent) c;
+            LSMRTreeDiskComponent component = (LSMRTreeDiskComponent) c;
             component.getBTree().destroy();
             component.getBloomFilter().destroy();
             component.getRTree().destroy();
@@ -154,9 +153,9 @@
     @Override
     public synchronized void clear() throws HyracksDataException {
         super.clear();
-        List<ILSMComponent> immutableComponents = componentsRef.get();
+        List<ILSMComponent> immutableComponents = diskComponents;
         for (ILSMComponent c : immutableComponents) {
-            LSMRTreeImmutableComponent component = (LSMRTreeImmutableComponent) c;
+            LSMRTreeDiskComponent component = (LSMRTreeDiskComponent) c;
             component.getBTree().deactivate();
             component.getBloomFilter().deactivate();
             component.getRTree().deactivate();
@@ -168,64 +167,23 @@
     }
 
     @Override
-    public void search(ILSMIndexOperationContext ictx, IIndexCursor cursor, ISearchPredicate pred)
-            throws HyracksDataException, IndexException {
-        LSMRTreeOpContext ctx = (LSMRTreeOpContext) ictx;
-        List<ILSMComponent> operationalComponents = ctx.getComponentHolder();
-        boolean includeMutableComponent = operationalComponents.get(0) == mutableComponent;
-        int numTrees = operationalComponents.size();
-
-        ListIterator<ILSMComponent> diskComponentIter = operationalComponents.listIterator();
-        ITreeIndexAccessor[] rTreeAccessors = new ITreeIndexAccessor[numTrees];
-        ITreeIndexAccessor[] bTreeAccessors = new ITreeIndexAccessor[numTrees];
-        int diskComponentIx = 0;
-        if (includeMutableComponent) {
-            rTreeAccessors[0] = ctx.memRTreeAccessor;
-            bTreeAccessors[0] = ctx.memBTreeAccessor;
-            diskComponentIx++;
-            diskComponentIter.next();
-        }
-
-        while (diskComponentIter.hasNext()) {
-            LSMRTreeImmutableComponent component = (LSMRTreeImmutableComponent) diskComponentIter.next();
-            RTree diskRTree = component.getRTree();
-            BTree diskBTree = component.getBTree();
-            rTreeAccessors[diskComponentIx] = diskRTree.createAccessor(NoOpOperationCallback.INSTANCE,
-                    NoOpOperationCallback.INSTANCE);
-            bTreeAccessors[diskComponentIx] = diskBTree.createAccessor(NoOpOperationCallback.INSTANCE,
-                    NoOpOperationCallback.INSTANCE);
-            diskComponentIx++;
-        }
-
-        LSMRTreeCursorInitialState initialState = new LSMRTreeCursorInitialState(numTrees, rtreeLeafFrameFactory,
-                rtreeInteriorFrameFactory, btreeLeafFrameFactory, ctx.getBTreeMultiComparator(), rTreeAccessors,
-                bTreeAccessors, includeMutableComponent, lsmHarness, comparatorFields, linearizerArray,
-                ctx.searchCallback, operationalComponents);
-        cursor.open(initialState, pred);
-    }
-
-    @Override
-    public boolean scheduleFlush(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
+    public void scheduleFlush(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
             throws HyracksDataException {
-        if (!mutableComponent.isModified()) {
-            return false;
-        }
+        ILSMComponent flushingComponent = ctx.getComponentHolder().get(0);
         LSMComponentFileReferences componentFileRefs = fileManager.getRelFlushFileReference();
         ILSMIndexOperationContext rctx = createOpContext(NoOpOperationCallback.INSTANCE);
-        LSMRTreeMutableComponent flushingComponent = (LSMRTreeMutableComponent) ctx.getComponentHolder().get(0);
         rctx.setOperation(IndexOperation.FLUSH);
         rctx.getComponentHolder().addAll(ctx.getComponentHolder());
         LSMRTreeAccessor accessor = new LSMRTreeAccessor(lsmHarness, rctx);
         ioScheduler.scheduleOperation(new LSMRTreeFlushOperation(accessor, flushingComponent, componentFileRefs
                 .getInsertIndexFileReference(), componentFileRefs.getDeleteIndexFileReference(), componentFileRefs
                 .getBloomFilterFileReference(), callback));
-        return true;
     }
 
     @Override
     public ILSMComponent flush(ILSMIOOperation operation) throws HyracksDataException, IndexException {
         LSMRTreeFlushOperation flushOp = (LSMRTreeFlushOperation) operation;
-        LSMRTreeMutableComponent flushingComponent = (LSMRTreeMutableComponent) flushOp.getFlushingComponent();
+        LSMRTreeMemoryComponent flushingComponent = (LSMRTreeMemoryComponent) flushOp.getFlushingComponent();
         // Renaming order is critical because we use assume ordering when we
         // read the file names when we open the tree.
         // The RTree should be renamed before the BTree.
@@ -236,7 +194,7 @@
         RTreeSearchCursor rtreeScanCursor = (RTreeSearchCursor) memRTreeAccessor.createSearchCursor();
         SearchPredicate rtreeNullPredicate = new SearchPredicate(null, null);
         memRTreeAccessor.search(rtreeScanCursor, rtreeNullPredicate);
-        LSMRTreeImmutableComponent component = createDiskComponent(componentFactory, flushOp.getRTreeFlushTarget(),
+        LSMRTreeDiskComponent component = createDiskComponent(componentFactory, flushOp.getRTreeFlushTarget(),
                 flushOp.getBTreeFlushTarget(), flushOp.getBloomFilterFlushTarget(), true);
         RTree diskRTree = component.getRTree();
         IIndexBulkLoader rTreeBulkloader;
@@ -329,17 +287,10 @@
     @Override
     public void scheduleMerge(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
             throws HyracksDataException, IndexException {
-        // Renaming order is critical because we use assume ordering when we
-        // read the file names when we open the tree.
-        // The RTree should be renamed before the BTree.
-        List<ILSMComponent> mergingComponents = ctx.getComponentHolder();
         ILSMIndexOperationContext rctx = createOpContext(NoOpOperationCallback.INSTANCE);
-        rctx.getComponentHolder().addAll(mergingComponents);
-        ITreeIndexCursor cursor = new LSMRTreeSortedCursor(rctx, linearizer);
-        ISearchPredicate rtreeSearchPred = new SearchPredicate(null, null);
-        search(rctx, cursor, rtreeSearchPred);
-
         rctx.setOperation(IndexOperation.MERGE);
+        List<ILSMComponent> mergingComponents = ctx.getComponentHolder();
+        ITreeIndexCursor cursor = new LSMRTreeSortedCursor(rctx, linearizer);
         LSMComponentFileReferences relMergeFileRefs = getMergeTargetFileName(mergingComponents);
         ILSMIndexAccessorInternal accessor = new LSMRTreeAccessor(lsmHarness, rctx);
         ioScheduler.scheduleOperation(new LSMRTreeMergeOperation((ILSMIndexAccessorInternal) accessor,
@@ -348,14 +299,16 @@
     }
 
     @Override
-    public ILSMComponent merge(List<ILSMComponent> mergedComponents, ILSMIOOperation operation)
-            throws HyracksDataException, IndexException {
+    public ILSMComponent merge(ILSMIOOperation operation) throws HyracksDataException, IndexException {
         LSMRTreeMergeOperation mergeOp = (LSMRTreeMergeOperation) operation;
         ITreeIndexCursor cursor = mergeOp.getCursor();
-        mergedComponents.addAll(mergeOp.getMergingComponents());
+        ISearchPredicate rtreeSearchPred = new SearchPredicate(null, null);
+        ILSMIndexOperationContext opCtx = ((LSMRTreeSortedCursor) cursor).getOpCtx();
+        opCtx.getComponentHolder().addAll(mergeOp.getMergingComponents());
+        search(opCtx, cursor, rtreeSearchPred);
 
-        LSMRTreeImmutableComponent mergedComponent = createDiskComponent(componentFactory,
-                mergeOp.getRTreeMergeTarget(), mergeOp.getBTreeMergeTarget(), mergeOp.getBloomFilterMergeTarget(), true);
+        LSMRTreeDiskComponent mergedComponent = createDiskComponent(componentFactory, mergeOp.getRTreeMergeTarget(),
+                mergeOp.getBTreeMergeTarget(), mergeOp.getBloomFilterMergeTarget(), true);
         IIndexBulkLoader bulkLoader = mergedComponent.getRTree().createBulkLoader(1.0f, false, 0L, false);
 
         try {
@@ -389,7 +342,7 @@
 
         public MultiComparator getMultiComparator() {
             LSMRTreeOpContext concreteCtx = (LSMRTreeOpContext) ctx;
-            return concreteCtx.rtreeOpContext.cmp;
+            return concreteCtx.currentRTreeOpContext.cmp;
         }
     }
 
@@ -427,7 +380,7 @@
             } catch (HyracksDataException | IndexException e) {
                 throw new TreeIndexException(e);
             }
-            bulkLoader = ((LSMRTreeImmutableComponent) component).getRTree().createBulkLoader(fillFactor, verifyInput,
+            bulkLoader = ((LSMRTreeDiskComponent) component).getRTree().createBulkLoader(fillFactor, verifyInput,
                     numElementsHint, false);
         }
 
@@ -459,19 +412,19 @@
         protected void cleanupArtifacts() throws HyracksDataException {
             if (!cleanedUpArtifacts) {
                 cleanedUpArtifacts = true;
-                ((LSMRTreeImmutableComponent) component).getRTree().deactivate();
-                ((LSMRTreeImmutableComponent) component).getRTree().destroy();
-                ((LSMRTreeImmutableComponent) component).getBTree().deactivate();
-                ((LSMRTreeImmutableComponent) component).getBTree().destroy();
-                ((LSMRTreeImmutableComponent) component).getBloomFilter().deactivate();
-                ((LSMRTreeImmutableComponent) component).getBloomFilter().destroy();
+                ((LSMRTreeDiskComponent) component).getRTree().deactivate();
+                ((LSMRTreeDiskComponent) component).getRTree().destroy();
+                ((LSMRTreeDiskComponent) component).getBTree().deactivate();
+                ((LSMRTreeDiskComponent) component).getBTree().destroy();
+                ((LSMRTreeDiskComponent) component).getBloomFilter().deactivate();
+                ((LSMRTreeDiskComponent) component).getBloomFilter().destroy();
             }
         }
     }
 
     @Override
     public void markAsValid(ILSMComponent lsmComponent) throws HyracksDataException {
-        LSMRTreeImmutableComponent component = (LSMRTreeImmutableComponent) lsmComponent;
+        LSMRTreeDiskComponent component = (LSMRTreeDiskComponent) lsmComponent;
         // Flush the bloom filter first.
         int fileId = component.getBloomFilter().getFileId();
         IBufferCache bufferCache = component.getBTree().getBufferCache();
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeAbstractCursor.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeAbstractCursor.java
index 0cd578a..4e322d4 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeAbstractCursor.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeAbstractCursor.java
@@ -12,146 +12,155 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package edu.uci.ics.hyracks.storage.am.lsm.rtree.impls;
-
-import java.util.List;
-
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
-import edu.uci.ics.hyracks.storage.am.btree.api.IBTreeLeafFrame;
-import edu.uci.ics.hyracks.storage.am.btree.impls.BTreeRangeSearchCursor;
-import edu.uci.ics.hyracks.storage.am.btree.impls.RangePredicate;
-import edu.uci.ics.hyracks.storage.am.common.api.ICursorInitialState;
-import edu.uci.ics.hyracks.storage.am.common.api.ISearchPredicate;
-import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexAccessor;
-import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexCursor;
-import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMHarness;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexOperationContext;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BloomFilterAwareBTreePointSearchCursor;
-import edu.uci.ics.hyracks.storage.am.rtree.api.IRTreeInteriorFrame;
-import edu.uci.ics.hyracks.storage.am.rtree.api.IRTreeLeafFrame;
-import edu.uci.ics.hyracks.storage.am.rtree.impls.RTreeSearchCursor;
-import edu.uci.ics.hyracks.storage.am.rtree.impls.SearchPredicate;
-import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
-import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPage;
-
-public abstract class LSMRTreeAbstractCursor implements ITreeIndexCursor {
-
-    protected RTreeSearchCursor[] rtreeCursors;
-    protected boolean open = false;
-    protected ITreeIndexCursor[] btreeCursors;
-    protected ITreeIndexAccessor[] rTreeAccessors;
-    protected ITreeIndexAccessor[] bTreeAccessors;
-    private MultiComparator btreeCmp;
-    protected int numberOfTrees;
-    protected SearchPredicate rtreeSearchPredicate;
-    protected RangePredicate btreeRangePredicate;
-    protected ITupleReference frameTuple;
-    protected boolean includeMemRTree;
-    protected ILSMHarness lsmHarness;
-    protected boolean foundNext;
-    protected final ILSMIndexOperationContext opCtx;
-
-    protected List<ILSMComponent> operationalComponents;
-
-    public LSMRTreeAbstractCursor(ILSMIndexOperationContext opCtx) {
-        super();
-        this.opCtx = opCtx;
-    }
-
-    public RTreeSearchCursor getCursor(int cursorIndex) {
-        return rtreeCursors[cursorIndex];
-    }
-
-    @Override
-    public void open(ICursorInitialState initialState, ISearchPredicate searchPred) throws HyracksDataException {
-        LSMRTreeCursorInitialState lsmInitialState = (LSMRTreeCursorInitialState) initialState;
-        btreeCmp = lsmInitialState.getBTreeCmp();
-        includeMemRTree = lsmInitialState.getIncludeMemComponent();
-        operationalComponents = lsmInitialState.getOperationalComponents();
-        lsmHarness = lsmInitialState.getLSMHarness();
-        numberOfTrees = lsmInitialState.getNumberOfTrees();
-        rTreeAccessors = lsmInitialState.getRTreeAccessors();
-        bTreeAccessors = lsmInitialState.getBTreeAccessors();
-
-        rtreeCursors = new RTreeSearchCursor[numberOfTrees];
-        btreeCursors = new ITreeIndexCursor[numberOfTrees];
-
-        int i = 0;
-        if (includeMemRTree) {
-            rtreeCursors[i] = new RTreeSearchCursor((IRTreeInteriorFrame) lsmInitialState
-                    .getRTreeInteriorFrameFactory().createFrame(), (IRTreeLeafFrame) lsmInitialState
-                    .getRTreeLeafFrameFactory().createFrame());
-
-            // No need for a bloom filter for the in-memory BTree.
-            btreeCursors[i] = new BTreeRangeSearchCursor((IBTreeLeafFrame) lsmInitialState.getBTreeLeafFrameFactory()
-                    .createFrame(), false);
-            ++i;
-        }
-        for (; i < numberOfTrees; i++) {
-            rtreeCursors[i] = new RTreeSearchCursor((IRTreeInteriorFrame) lsmInitialState
-                    .getRTreeInteriorFrameFactory().createFrame(), (IRTreeLeafFrame) lsmInitialState
-                    .getRTreeLeafFrameFactory().createFrame());
-
-            btreeCursors[i] = new BloomFilterAwareBTreePointSearchCursor((IBTreeLeafFrame) lsmInitialState
-                    .getBTreeLeafFrameFactory().createFrame(), false,
-                    ((LSMRTreeImmutableComponent) operationalComponents.get(i)).getBloomFilter());
-        }
-
-        rtreeSearchPredicate = (SearchPredicate) searchPred;
-        btreeRangePredicate = new RangePredicate(null, null, true, true, btreeCmp, btreeCmp);
-
-        open = true;
-    }
-
-    @Override
-    public ICachedPage getPage() {
-        // do nothing
-        return null;
-    }
-
-    @Override
-    public void close() throws HyracksDataException {
-        if (!open) {
-            return;
-        }
-
-        try {
-            if (rtreeCursors != null && btreeCursors != null) {
-                for (int i = 0; i < numberOfTrees; i++) {
-                    rtreeCursors[i].close();
-                    btreeCursors[i].close();
-                }
-            }
-            rtreeCursors = null;
-            btreeCursors = null;
-        } finally {
-            lsmHarness.endSearch(opCtx);
-        }
-
-        open = false;
-    }
-
-    @Override
-    public void setBufferCache(IBufferCache bufferCache) {
-        // do nothing
-    }
-
-    @Override
-    public void setFileId(int fileId) {
-        // do nothing
-    }
-
-    @Override
-    public ITupleReference getTuple() {
-        return frameTuple;
-    }
-
-    @Override
-    public boolean exclusiveLatchNodes() {
-        return false;
-    }
-
+package edu.uci.ics.hyracks.storage.am.lsm.rtree.impls;
+
+import java.util.List;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
+import edu.uci.ics.hyracks.storage.am.btree.api.IBTreeLeafFrame;
+import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
+import edu.uci.ics.hyracks.storage.am.btree.impls.BTreeRangeSearchCursor;
+import edu.uci.ics.hyracks.storage.am.btree.impls.RangePredicate;
+import edu.uci.ics.hyracks.storage.am.common.api.ICursorInitialState;
+import edu.uci.ics.hyracks.storage.am.common.api.ISearchPredicate;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexAccessor;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexCursor;
+import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
+import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent.LSMComponentType;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMHarness;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexOperationContext;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BloomFilterAwareBTreePointSearchCursor;
+import edu.uci.ics.hyracks.storage.am.rtree.api.IRTreeInteriorFrame;
+import edu.uci.ics.hyracks.storage.am.rtree.api.IRTreeLeafFrame;
+import edu.uci.ics.hyracks.storage.am.rtree.impls.RTree;
+import edu.uci.ics.hyracks.storage.am.rtree.impls.RTreeSearchCursor;
+import edu.uci.ics.hyracks.storage.am.rtree.impls.SearchPredicate;
+import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
+import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPage;
+
+public abstract class LSMRTreeAbstractCursor implements ITreeIndexCursor {
+
+    protected boolean open;
+    protected RTreeSearchCursor[] rtreeCursors;
+    protected ITreeIndexCursor[] btreeCursors;
+    protected ITreeIndexAccessor[] rtreeAccessors;
+    protected ITreeIndexAccessor[] btreeAccessors;
+    private MultiComparator btreeCmp;
+    protected int numberOfTrees;
+    protected SearchPredicate rtreeSearchPredicate;
+    protected RangePredicate btreeRangePredicate;
+    protected ITupleReference frameTuple;
+    protected boolean includeMutableComponent;
+    protected ILSMHarness lsmHarness;
+    protected boolean foundNext;
+    protected final ILSMIndexOperationContext opCtx;
+
+    protected List<ILSMComponent> operationalComponents;
+
+    public LSMRTreeAbstractCursor(ILSMIndexOperationContext opCtx) {
+        super();
+        this.opCtx = opCtx;
+    }
+
+    public RTreeSearchCursor getCursor(int cursorIndex) {
+        return rtreeCursors[cursorIndex];
+    }
+
+    @Override
+    public void open(ICursorInitialState initialState, ISearchPredicate searchPred) throws HyracksDataException {
+        LSMRTreeCursorInitialState lsmInitialState = (LSMRTreeCursorInitialState) initialState;
+        btreeCmp = lsmInitialState.getBTreeCmp();
+
+        operationalComponents = lsmInitialState.getOperationalComponents();
+        lsmHarness = lsmInitialState.getLSMHarness();
+        numberOfTrees = operationalComponents.size();
+
+        rtreeCursors = new RTreeSearchCursor[numberOfTrees];
+        btreeCursors = new ITreeIndexCursor[numberOfTrees];
+        rtreeAccessors = new ITreeIndexAccessor[numberOfTrees];
+        btreeAccessors = new ITreeIndexAccessor[numberOfTrees];
+
+        includeMutableComponent = false;
+        for (int i = 0; i < numberOfTrees; i++) {
+            ILSMComponent component = operationalComponents.get(i);
+            RTree rtree;
+            BTree btree;
+            if (component.getType() == LSMComponentType.MEMORY) {
+                includeMutableComponent = true;
+                // No need for a bloom filter for the in-memory BTree.
+                btreeCursors[i] = new BTreeRangeSearchCursor((IBTreeLeafFrame) lsmInitialState
+                        .getBTreeLeafFrameFactory().createFrame(), false);
+                rtree = (RTree) ((LSMRTreeMemoryComponent) component).getRTree();
+                btree = (BTree) ((LSMRTreeMemoryComponent) component).getBTree();
+            } else {
+                btreeCursors[i] = new BloomFilterAwareBTreePointSearchCursor((IBTreeLeafFrame) lsmInitialState
+                        .getBTreeLeafFrameFactory().createFrame(), false,
+                        ((LSMRTreeDiskComponent) operationalComponents.get(i)).getBloomFilter());
+                rtree = (RTree) ((LSMRTreeDiskComponent) component).getRTree();
+                btree = (BTree) ((LSMRTreeDiskComponent) component).getBTree();
+            }
+            rtreeCursors[i] = new RTreeSearchCursor((IRTreeInteriorFrame) lsmInitialState
+                    .getRTreeInteriorFrameFactory().createFrame(), (IRTreeLeafFrame) lsmInitialState
+                    .getRTreeLeafFrameFactory().createFrame());
+            rtreeAccessors[i] = rtree.createAccessor(NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
+            btreeAccessors[i] = btree.createAccessor(NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
+        }
+
+        rtreeSearchPredicate = (SearchPredicate) searchPred;
+        btreeRangePredicate = new RangePredicate(null, null, true, true, btreeCmp, btreeCmp);
+
+        open = true;
+    }
+
+    @Override
+    public ICachedPage getPage() {
+        // do nothing
+        return null;
+    }
+
+    @Override
+    public void close() throws HyracksDataException {
+        if (!open) {
+            return;
+        }
+
+        try {
+            if (rtreeCursors != null && btreeCursors != null) {
+                for (int i = 0; i < numberOfTrees; i++) {
+                    rtreeCursors[i].close();
+                    btreeCursors[i].close();
+                }
+            }
+            rtreeCursors = null;
+            btreeCursors = null;
+        } finally {
+            lsmHarness.endSearch(opCtx);
+        }
+
+        open = false;
+    }
+
+    @Override
+    public void setBufferCache(IBufferCache bufferCache) {
+        // do nothing
+    }
+
+    @Override
+    public void setFileId(int fileId) {
+        // do nothing
+    }
+
+    @Override
+    public ITupleReference getTuple() {
+        return frameTuple;
+    }
+
+    @Override
+    public boolean exclusiveLatchNodes() {
+        return false;
+    }
+
 }
\ No newline at end of file
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeCursorInitialState.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeCursorInitialState.java
index 21230b0..27545b9 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeCursorInitialState.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeCursorInitialState.java
@@ -20,7 +20,6 @@
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ICursorInitialState;
 import edu.uci.ics.hyracks.storage.am.common.api.ISearchOperationCallback;
-import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
@@ -29,35 +28,26 @@
 
 public class LSMRTreeCursorInitialState implements ICursorInitialState {
 
-    private final int numberOfTrees;
     private final ITreeIndexFrameFactory rtreeInteriorFrameFactory;
     private final ITreeIndexFrameFactory rtreeLeafFrameFactory;
     private final ITreeIndexFrameFactory btreeLeafFrameFactory;
     private final MultiComparator btreeCmp;
     private final MultiComparator hilbertCmp;
-    private final ITreeIndexAccessor[] rTreeAccessors;
-    private final ITreeIndexAccessor[] bTreeAccessors;
-    private final boolean includeMemRTree;
     private final ILSMHarness lsmHarness;
     private final int[] comparatorFields;
 
     private ISearchOperationCallback searchCallback;
     private final List<ILSMComponent> operationalComponents;
 
-    public LSMRTreeCursorInitialState(int numberOfTrees, ITreeIndexFrameFactory rtreeLeafFrameFactory,
+    public LSMRTreeCursorInitialState(ITreeIndexFrameFactory rtreeLeafFrameFactory,
             ITreeIndexFrameFactory rtreeInteriorFrameFactory, ITreeIndexFrameFactory btreeLeafFrameFactory,
-            MultiComparator btreeCmp, ITreeIndexAccessor[] rTreeAccessors, ITreeIndexAccessor[] bTreeAccessors,
-            boolean includeMemRTree, ILSMHarness lsmHarness, int[] comparatorFields,
+            MultiComparator btreeCmp, ILSMHarness lsmHarness, int[] comparatorFields,
             IBinaryComparatorFactory[] linearizerArray, ISearchOperationCallback searchCallback,
             List<ILSMComponent> operationalComponents) {
-        this.numberOfTrees = numberOfTrees;
         this.rtreeLeafFrameFactory = rtreeLeafFrameFactory;
         this.rtreeInteriorFrameFactory = rtreeInteriorFrameFactory;
         this.btreeLeafFrameFactory = btreeLeafFrameFactory;
         this.btreeCmp = btreeCmp;
-        this.rTreeAccessors = rTreeAccessors;
-        this.bTreeAccessors = bTreeAccessors;
-        this.includeMemRTree = includeMemRTree;
         this.lsmHarness = lsmHarness;
         this.comparatorFields = comparatorFields;
         this.hilbertCmp = MultiComparator.create(linearizerArray);
@@ -73,10 +63,6 @@
         return comparatorFields;
     }
 
-    public int getNumberOfTrees() {
-        return numberOfTrees;
-    }
-
     public ITreeIndexFrameFactory getRTreeInteriorFrameFactory() {
         return rtreeInteriorFrameFactory;
     }
@@ -106,18 +92,6 @@
         return operationalComponents;
     }
 
-    public ITreeIndexAccessor[] getRTreeAccessors() {
-        return rTreeAccessors;
-    }
-
-    public ITreeIndexAccessor[] getBTreeAccessors() {
-        return bTreeAccessors;
-    }
-
-    public boolean getIncludeMemComponent() {
-        return includeMemRTree;
-    }
-
     public ILSMHarness getLSMHarness() {
         return lsmHarness;
     }
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeImmutableComponent.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeDiskComponent.java
similarity index 86%
rename from hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeImmutableComponent.java
rename to hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeDiskComponent.java
index cb290c7..7bc3f79 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeImmutableComponent.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeDiskComponent.java
@@ -17,15 +17,15 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.am.bloomfilter.impls.BloomFilter;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.AbstractImmutableLSMComponent;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.AbstractDiskLSMComponent;
 import edu.uci.ics.hyracks.storage.am.rtree.impls.RTree;
 
-public class LSMRTreeImmutableComponent extends AbstractImmutableLSMComponent {
+public class LSMRTreeDiskComponent extends AbstractDiskLSMComponent {
     private final RTree rtree;
     private final BTree btree;
     private final BloomFilter bloomFilter;
 
-    public LSMRTreeImmutableComponent(RTree rtree, BTree btree, BloomFilter bloomFilter) {
+    public LSMRTreeDiskComponent(RTree rtree, BTree btree, BloomFilter bloomFilter) {
         this.rtree = rtree;
         this.btree = btree;
         this.bloomFilter = bloomFilter;
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeComponentFactory.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeDiskComponentFactory.java
similarity index 87%
rename from hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeComponentFactory.java
rename to hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeDiskComponentFactory.java
index 8f618da..a130562 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeComponentFactory.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeDiskComponentFactory.java
@@ -26,12 +26,12 @@
 import edu.uci.ics.hyracks.storage.am.rtree.impls.RTree;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 
-public class LSMRTreeComponentFactory implements ILSMComponentFactory {
+public class LSMRTreeDiskComponentFactory implements ILSMComponentFactory {
     private final TreeIndexFactory<RTree> rtreeFactory;
     private final TreeIndexFactory<BTree> btreeFactory;
     private final BloomFilterFactory bloomFilterFactory;
 
-    public LSMRTreeComponentFactory(TreeIndexFactory<RTree> rtreeFactory, TreeIndexFactory<BTree> btreeFactory,
+    public LSMRTreeDiskComponentFactory(TreeIndexFactory<RTree> rtreeFactory, TreeIndexFactory<BTree> btreeFactory,
             BloomFilterFactory bloomFilterFactory) {
         this.rtreeFactory = rtreeFactory;
         this.btreeFactory = btreeFactory;
@@ -41,7 +41,7 @@
     @Override
     public ILSMComponent createLSMComponentInstance(LSMComponentFileReferences cfr) throws IndexException,
             HyracksDataException {
-        return new LSMRTreeImmutableComponent(rtreeFactory.createIndexInstance(cfr.getInsertIndexFileReference()),
+        return new LSMRTreeDiskComponent(rtreeFactory.createIndexInstance(cfr.getInsertIndexFileReference()),
                 btreeFactory.createIndexInstance(cfr.getDeleteIndexFileReference()),
                 bloomFilterFactory.createBloomFiltertInstance(cfr.getBloomFilterFileReference()));
     }
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeFlushOperation.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeFlushOperation.java
index 68098bb..18d7a7e 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeFlushOperation.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeFlushOperation.java
@@ -64,8 +64,9 @@
     }
 
     @Override
-    public void perform() throws HyracksDataException, IndexException {
+    public Boolean call() throws HyracksDataException, IndexException {
         accessor.flush(this);
+        return true;
     }
 
     @Override
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeMutableComponent.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeMemoryComponent.java
similarity index 82%
rename from hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeMutableComponent.java
rename to hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeMemoryComponent.java
index 7d572ad..452643b 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeMutableComponent.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeMemoryComponent.java
@@ -18,19 +18,18 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.AbstractMutableLSMComponent;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.AbstractMemoryLSMComponent;
 import edu.uci.ics.hyracks.storage.am.rtree.impls.RTree;
 
-public class LSMRTreeMutableComponent extends AbstractMutableLSMComponent {
+public class LSMRTreeMemoryComponent extends AbstractMemoryLSMComponent {
 
     private final RTree rtree;
     private final BTree btree;
-    private final IVirtualBufferCache vbc;
 
-    public LSMRTreeMutableComponent(RTree rtree, BTree btree, IVirtualBufferCache vbc) {
+    public LSMRTreeMemoryComponent(RTree rtree, BTree btree, IVirtualBufferCache vbc, boolean isActive) {
+        super(vbc, isActive);
         this.rtree = rtree;
         this.btree = btree;
-        this.vbc = vbc;
     }
 
     public RTree getRTree() {
@@ -42,11 +41,6 @@
     }
 
     @Override
-    protected boolean isFull() {
-        return vbc.isFull();
-    }
-
-    @Override
     protected void reset() throws HyracksDataException {
         super.reset();
         rtree.deactivate();
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeMergeOperation.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeMergeOperation.java
index ef67a2b..da7a2fb 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeMergeOperation.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeMergeOperation.java
@@ -53,7 +53,7 @@
     public Set<IODeviceHandle> getReadDevices() {
         Set<IODeviceHandle> devs = new HashSet<IODeviceHandle>();
         for (ILSMComponent o : mergingComponents) {
-            LSMRTreeImmutableComponent component = (LSMRTreeImmutableComponent) o;
+            LSMRTreeDiskComponent component = (LSMRTreeDiskComponent) o;
             devs.add(component.getRTree().getFileReference().getDeviceHandle());
             if (component.getBTree() != null) {
                 devs.add(component.getBTree().getFileReference().getDeviceHandle());
@@ -75,8 +75,9 @@
     }
 
     @Override
-    public void perform() throws HyracksDataException, IndexException {
+    public Boolean call() throws HyracksDataException, IndexException {
         accessor.merge(this);
+        return true;
     }
 
     @Override
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeOpContext.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeOpContext.java
index 8607a05..b94feba 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeOpContext.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeOpContext.java
@@ -24,7 +24,6 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IModificationOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.api.ISearchOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrameFactory;
-import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrame;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
@@ -37,43 +36,69 @@
 
 public final class LSMRTreeOpContext implements ILSMIndexOperationContext {
 
-    public RTreeOpContext rtreeOpContext;
-    public BTreeOpContext btreeOpContext;
-    public final RTree.RTreeAccessor memRTreeAccessor;
-    public final BTree.BTreeAccessor memBTreeAccessor;
+    public RTree.RTreeAccessor[] mutableRTreeAccessors;
+    public RTree.RTreeAccessor currentMutableRTreeAccessor;
+    public BTree.BTreeAccessor[] mutableBTreeAccessors;
+    public BTree.BTreeAccessor currentMutableBTreeAccessor;
+
+    public RTreeOpContext[] rtreeOpContexts;
+    public BTreeOpContext[] btreeOpContexts;
+    public RTreeOpContext currentRTreeOpContext;
+    public BTreeOpContext currentBTreeOpContext;
+
     private IndexOperation op;
     public final List<ILSMComponent> componentHolder;
     public final IModificationOperationCallback modificationCallback;
     public final ISearchOperationCallback searchCallback;
 
-    public LSMRTreeOpContext(RTree.RTreeAccessor memRtreeAccessor, IRTreeLeafFrame rtreeLeafFrame,
-            IRTreeInteriorFrame rtreeInteriorFrame, ITreeIndexMetaDataFrame rtreeMetaFrame, int rTreeHeightHint,
-            BTree.BTreeAccessor memBtreeAccessor, ITreeIndexFrameFactory btreeLeafFrameFactory,
-            ITreeIndexFrameFactory btreeInteriorFrameFactory, ITreeIndexMetaDataFrame btreeMetaFrame,
-            IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
-            IModificationOperationCallback modificationCallback, ISearchOperationCallback searchCallback) {
-        this.memRTreeAccessor = memRtreeAccessor;
-        this.memBTreeAccessor = memBtreeAccessor;
+    public LSMRTreeOpContext(List<ILSMComponent> mutableComponents, IRTreeLeafFrame rtreeLeafFrame,
+            IRTreeInteriorFrame rtreeInteriorFrame, ITreeIndexFrameFactory btreeLeafFrameFactory,
+            ITreeIndexFrameFactory btreeInteriorFrameFactory, IBinaryComparatorFactory[] rtreeCmpFactories,
+            IBinaryComparatorFactory[] btreeCmpFactories, IModificationOperationCallback modificationCallback,
+            ISearchOperationCallback searchCallback) {
+        mutableRTreeAccessors = new RTree.RTreeAccessor[mutableComponents.size()];
+        mutableBTreeAccessors = new BTree.BTreeAccessor[mutableComponents.size()];
+        rtreeOpContexts = new RTreeOpContext[mutableComponents.size()];
+        btreeOpContexts = new BTreeOpContext[mutableComponents.size()];
+
+        for (int i = 0; i < mutableComponents.size(); i++) {
+            LSMRTreeMemoryComponent mutableComponent = (LSMRTreeMemoryComponent) mutableComponents.get(i);
+            mutableRTreeAccessors[i] = (RTree.RTreeAccessor) mutableComponent.getRTree().createAccessor(
+                    NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
+            mutableBTreeAccessors[i] = (BTree.BTreeAccessor) mutableComponent.getBTree().createAccessor(
+                    NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
+
+            rtreeOpContexts[i] = mutableRTreeAccessors[i].getOpContext();
+            btreeOpContexts[i] = mutableBTreeAccessors[i].getOpContext();
+        }
+
+        assert mutableComponents.size() > 0;
+        currentRTreeOpContext = rtreeOpContexts[0];
+        currentBTreeOpContext = btreeOpContexts[0];
         this.componentHolder = new LinkedList<ILSMComponent>();
         this.modificationCallback = modificationCallback;
         this.searchCallback = searchCallback;
-        this.rtreeOpContext = new RTreeOpContext(rtreeLeafFrame, rtreeInteriorFrame, rtreeMetaFrame, rtreeCmpFactories,
-                rTreeHeightHint, NoOpOperationCallback.INSTANCE);
-        this.btreeOpContext = new BTreeOpContext(memBtreeAccessor, btreeLeafFrameFactory, btreeInteriorFrameFactory,
-                btreeMetaFrame, btreeCmpFactories, NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
     }
 
     public void setOperation(IndexOperation newOp) {
         reset();
-        if (newOp == IndexOperation.INSERT) {
-            rtreeOpContext.setOperation(newOp);
-        } else if (newOp == IndexOperation.DELETE) {
-            btreeOpContext.setOperation(IndexOperation.INSERT);
-        }
         this.op = newOp;
     }
 
     @Override
+    public void setCurrentMutableComponentId(int currentMutableComponentId) {
+        currentMutableRTreeAccessor = mutableRTreeAccessors[currentMutableComponentId];
+        currentMutableBTreeAccessor = mutableBTreeAccessors[currentMutableComponentId];
+        currentRTreeOpContext = rtreeOpContexts[currentMutableComponentId];
+        currentBTreeOpContext = btreeOpContexts[currentMutableComponentId];
+        if (op == IndexOperation.INSERT) {
+            currentRTreeOpContext.setOperation(op);
+        } else if (op == IndexOperation.DELETE) {
+            currentBTreeOpContext.setOperation(IndexOperation.INSERT);
+        }
+    }
+
+    @Override
     public void reset() {
         componentHolder.clear();
     }
@@ -84,7 +109,7 @@
     }
 
     public MultiComparator getBTreeMultiComparator() {
-        return btreeOpContext.cmp;
+        return currentBTreeOpContext.cmp;
     }
 
     @Override
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeSearchCursor.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeSearchCursor.java
index 9b0869c..30dd467 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeSearchCursor.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeSearchCursor.java
@@ -61,7 +61,7 @@
         if (currentCursor < numberOfTrees) {
             rtreeCursors[currentCursor].reset();
             try {
-                rTreeAccessors[currentCursor].search(rtreeCursors[currentCursor], rtreeSearchPredicate);
+                rtreeAccessors[currentCursor].search(rtreeCursors[currentCursor], rtreeSearchPredicate);
             } catch (IndexException e) {
                 throw new HyracksDataException(e);
             }
@@ -80,14 +80,10 @@
 
                 boolean killerTupleFound = false;
                 for (int i = 0; i <= currentCursor; i++) {
-                    try {
-                        btreeCursors[i].reset();
-                        btreeRangePredicate.setHighKey(currentTuple, true);
-                        btreeRangePredicate.setLowKey(currentTuple, true);
-                        bTreeAccessors[i].search(btreeCursors[i], btreeRangePredicate);
-                    } catch (IndexException e) {
-                        throw new HyracksDataException(e);
-                    }
+                    btreeCursors[i].reset();
+                    btreeRangePredicate.setHighKey(currentTuple, true);
+                    btreeRangePredicate.setLowKey(currentTuple, true);
+                    btreeAccessors[i].search(btreeCursors[i], btreeRangePredicate);
                     try {
                         if (btreeCursors[i].hasNext()) {
                             killerTupleFound = true;
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeSortedCursor.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeSortedCursor.java
index 31dfe27..dd31165 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeSortedCursor.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeSortedCursor.java
@@ -36,6 +36,10 @@
         reset();
     }
 
+    public ILSMIndexOperationContext getOpCtx() {
+        return opCtx;
+    }
+
     @Override
     public void reset() throws HyracksDataException {
         depletedRtreeCursors = new boolean[numberOfTrees];
@@ -44,7 +48,7 @@
             for (int i = 0; i < numberOfTrees; i++) {
                 rtreeCursors[i].reset();
                 try {
-                    rTreeAccessors[i].search(rtreeCursors[i], rtreeSearchPredicate);
+                    rtreeAccessors[i].search(rtreeCursors[i], rtreeSearchPredicate);
                 } catch (IndexException e) {
                     throw new HyracksDataException(e);
                 }
@@ -103,7 +107,7 @@
                     btreeCursors[i].reset();
                     btreeRangePredicate.setHighKey(frameTuple, true);
                     btreeRangePredicate.setLowKey(frameTuple, true);
-                    bTreeAccessors[i].search(btreeCursors[i], btreeRangePredicate);
+                    btreeAccessors[i].search(btreeCursors[i], btreeRangePredicate);
                 } catch (IndexException e) {
                     throw new HyracksDataException(e);
                 }
@@ -138,7 +142,7 @@
         for (int i = 0; i < numberOfTrees; i++) {
             rtreeCursors[i].reset();
             try {
-                rTreeAccessors[i].search(rtreeCursors[i], rtreeSearchPredicate);
+                rtreeAccessors[i].search(rtreeCursors[i], rtreeSearchPredicate);
             } catch (IndexException e) {
                 throw new HyracksDataException(e);
             }
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuples.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuples.java
index 0be497a..812e942 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuples.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuples.java
@@ -16,7 +16,6 @@
 package edu.uci.ics.hyracks.storage.am.lsm.rtree.impls;
 
 import java.util.List;
-import java.util.ListIterator;
 
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ILinearizeComparatorFactory;
@@ -25,7 +24,6 @@
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTreeRangeSearchCursor;
 import edu.uci.ics.hyracks.storage.am.btree.impls.RangePredicate;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexBulkLoader;
-import edu.uci.ics.hyracks.storage.am.common.api.IIndexCursor;
 import edu.uci.ics.hyracks.storage.am.common.api.IModificationOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.api.ISearchOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.api.ISearchPredicate;
@@ -51,6 +49,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMComponentFileReferences;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMIndexSearchCursor;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMTreeIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.TreeIndexFactory;
 import edu.uci.ics.hyracks.storage.am.rtree.impls.RTree;
@@ -67,7 +66,7 @@
     // because it should have a different tuple writer in it's leaf frames.
     private final ILSMComponentFactory bulkLoaComponentFactory;
 
-    public LSMRTreeWithAntiMatterTuples(IVirtualBufferCache virtualBufferCache,
+    public LSMRTreeWithAntiMatterTuples(List<IVirtualBufferCache> virtualBufferCaches,
             ITreeIndexFrameFactory rtreeInteriorFrameFactory, ITreeIndexFrameFactory rtreeLeafFrameFactory,
             ITreeIndexFrameFactory btreeInteriorFrameFactory, ITreeIndexFrameFactory btreeLeafFrameFactory,
             ILSMIndexFileManager fileManager, TreeIndexFactory<RTree> diskRTreeFactory,
@@ -75,20 +74,19 @@
             IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
             ILinearizeComparatorFactory linearizer, int[] comparatorFields, IBinaryComparatorFactory[] linearizerArray,
             ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        super(virtualBufferCache, rtreeInteriorFrameFactory, rtreeLeafFrameFactory, btreeInteriorFrameFactory,
-                btreeLeafFrameFactory, fileManager, diskRTreeFactory, new LSMRTreeWithAntiMatterTuplesComponentFactory(
-                        diskRTreeFactory), diskFileMapProvider, fieldCount, rtreeCmpFactories, btreeCmpFactories,
-                linearizer, comparatorFields, linearizerArray, 0, mergePolicy, opTracker, ioScheduler,
-                ioOpCallbackProvider);
-        bulkLoaComponentFactory = new LSMRTreeWithAntiMatterTuplesComponentFactory(bulkLoadRTreeFactory);
+            ILSMIOOperationCallback ioOpCallback) {
+        super(virtualBufferCaches, rtreeInteriorFrameFactory, rtreeLeafFrameFactory, btreeInteriorFrameFactory,
+                btreeLeafFrameFactory, fileManager, new LSMRTreeWithAntiMatterTuplesDiskComponentFactory(diskRTreeFactory),
+                diskFileMapProvider, fieldCount, rtreeCmpFactories, btreeCmpFactories, linearizer, comparatorFields,
+                linearizerArray, 0, mergePolicy, opTracker, ioScheduler, ioOpCallback);
+        bulkLoaComponentFactory = new LSMRTreeWithAntiMatterTuplesDiskComponentFactory(bulkLoadRTreeFactory);
         this.bTreeTupleSorter = null;
     }
 
     @Override
     public synchronized void activate() throws HyracksDataException {
         super.activate();
-        List<ILSMComponent> immutableComponents = componentsRef.get();
+        List<ILSMComponent> immutableComponents = diskComponents;
         immutableComponents.clear();
         List<LSMComponentFileReferences> validFileReferences;
         try {
@@ -97,7 +95,7 @@
             throw new HyracksDataException(e);
         }
         for (LSMComponentFileReferences lsmComonentFileReference : validFileReferences) {
-            LSMRTreeImmutableComponent component;
+            LSMRTreeDiskComponent component;
             try {
                 component = createDiskComponent(componentFactory,
                         lsmComonentFileReference.getInsertIndexFileReference(), null, null, false);
@@ -112,9 +110,9 @@
     @Override
     public synchronized void deactivate(boolean flushOnExit) throws HyracksDataException {
         super.deactivate(flushOnExit);
-        List<ILSMComponent> immutableComponents = componentsRef.get();
+        List<ILSMComponent> immutableComponents = diskComponents;
         for (ILSMComponent c : immutableComponents) {
-            RTree rtree = (RTree) ((LSMRTreeImmutableComponent) c).getRTree();
+            RTree rtree = (RTree) ((LSMRTreeDiskComponent) c).getRTree();
             rtree.deactivate();
         }
         isActivated = false;
@@ -128,9 +126,9 @@
     @Override
     public synchronized void destroy() throws HyracksDataException {
         super.destroy();
-        List<ILSMComponent> immutableComponents = componentsRef.get();
+        List<ILSMComponent> immutableComponents = diskComponents;
         for (ILSMComponent c : immutableComponents) {
-            RTree rtree = (RTree) ((LSMRTreeImmutableComponent) c).getRTree();
+            RTree rtree = (RTree) ((LSMRTreeDiskComponent) c).getRTree();
             rtree.destroy();
         }
         fileManager.deleteDirs();
@@ -139,9 +137,9 @@
     @Override
     public synchronized void clear() throws HyracksDataException {
         super.clear();
-        List<ILSMComponent> immutableComponents = componentsRef.get();
+        List<ILSMComponent> immutableComponents = diskComponents;
         for (ILSMComponent c : immutableComponents) {
-            RTree rtree = (RTree) ((LSMRTreeImmutableComponent) c).getRTree();
+            RTree rtree = (RTree) ((LSMRTreeDiskComponent) c).getRTree();
             rtree.deactivate();
             rtree.destroy();
         }
@@ -149,65 +147,16 @@
     }
 
     @Override
-    public void search(ILSMIndexOperationContext ictx, IIndexCursor cursor, ISearchPredicate pred)
-            throws HyracksDataException, IndexException {
-        LSMRTreeOpContext ctx = (LSMRTreeOpContext) ictx;
-        List<ILSMComponent> operationalComponents = ictx.getComponentHolder();
-        boolean includeMutableComponent = operationalComponents.get(0) == mutableComponent;
-        LSMRTreeWithAntiMatterTuplesSearchCursor lsmTreeCursor = (LSMRTreeWithAntiMatterTuplesSearchCursor) cursor;
-        int numDiskRComponents = operationalComponents.size();
-
-        LSMRTreeCursorInitialState initialState;
-        ITreeIndexAccessor[] bTreeAccessors = null;
-        if (includeMutableComponent) {
-            // Only in-memory BTree
-            bTreeAccessors = new ITreeIndexAccessor[1];
-            bTreeAccessors[0] = ctx.memBTreeAccessor;
-        }
-
-        initialState = new LSMRTreeCursorInitialState(numDiskRComponents, rtreeLeafFrameFactory,
-                rtreeInteriorFrameFactory, btreeLeafFrameFactory, ctx.getBTreeMultiComparator(), null, bTreeAccessors,
-                includeMutableComponent, lsmHarness, comparatorFields, linearizerArray, ctx.searchCallback,
-                operationalComponents);
-
-        lsmTreeCursor.open(initialState, pred);
-
-        ListIterator<ILSMComponent> diskComponentsIter = operationalComponents.listIterator();
-        int diskComponentIx = 0;
-        if (includeMutableComponent) {
-            // Open cursor of in-memory RTree
-            ctx.memRTreeAccessor.search(lsmTreeCursor.getMemRTreeCursor(), pred);
-            diskComponentIx++;
-            diskComponentsIter.next();
-        }
-
-        // Open cursors of on-disk RTrees.
-        ITreeIndexAccessor[] diskRTreeAccessors = new ITreeIndexAccessor[numDiskRComponents];
-        while (diskComponentsIter.hasNext()) {
-            RTree diskRTree = (RTree) ((LSMRTreeImmutableComponent) diskComponentsIter.next()).getRTree();
-            diskRTreeAccessors[diskComponentIx] = diskRTree.createAccessor(NoOpOperationCallback.INSTANCE,
-                    NoOpOperationCallback.INSTANCE);
-            diskRTreeAccessors[diskComponentIx].search(lsmTreeCursor.getCursor(diskComponentIx), pred);
-            diskComponentIx++;
-        }
-        lsmTreeCursor.initPriorityQueue();
-    }
-
-    @Override
-    public boolean scheduleFlush(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
+    public void scheduleFlush(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
             throws HyracksDataException {
-        if (!mutableComponent.isModified()) {
-            return false;
-        }
+        ILSMComponent flushingComponent = ctx.getComponentHolder().get(0);
         LSMRTreeOpContext opCtx = createOpContext(NoOpOperationCallback.INSTANCE);
         LSMComponentFileReferences relFlushFileRefs = fileManager.getRelFlushFileReference();
-        ILSMComponent flushingComponent = ctx.getComponentHolder().get(0);
         opCtx.setOperation(IndexOperation.FLUSH);
         opCtx.getComponentHolder().add(flushingComponent);
         ILSMIndexAccessorInternal accessor = new LSMRTreeWithAntiMatterTuplesAccessor(lsmHarness, opCtx);
         ioScheduler.scheduleOperation(new LSMRTreeFlushOperation(accessor, flushingComponent, relFlushFileRefs
                 .getInsertIndexFileReference(), null, null, callback));
-        return true;
     }
 
     @Override
@@ -216,14 +165,14 @@
         // Renaming order is critical because we use assume ordering when we
         // read the file names when we open the tree.
         // The RTree should be renamed before the BTree.
-        LSMRTreeMutableComponent flushingComponent = (LSMRTreeMutableComponent) flushOp.getFlushingComponent();
+        LSMRTreeMemoryComponent flushingComponent = (LSMRTreeMemoryComponent) flushOp.getFlushingComponent();
         ITreeIndexAccessor memRTreeAccessor = flushingComponent.getRTree().createAccessor(
                 NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
         RTreeSearchCursor rtreeScanCursor = (RTreeSearchCursor) memRTreeAccessor.createSearchCursor();
         SearchPredicate rtreeNullPredicate = new SearchPredicate(null, null);
         memRTreeAccessor.search(rtreeScanCursor, rtreeNullPredicate);
-        LSMRTreeImmutableComponent component = createDiskComponent(componentFactory, flushOp.getRTreeFlushTarget(),
-                null, null, true);
+        LSMRTreeDiskComponent component = createDiskComponent(componentFactory, flushOp.getRTreeFlushTarget(), null,
+                null, true);
         RTree diskRTree = component.getRTree();
 
         // scan the memory BTree
@@ -296,13 +245,10 @@
     @Override
     public void scheduleMerge(ILSMIndexOperationContext ctx, ILSMIOOperationCallback callback)
             throws HyracksDataException, IndexException {
-        List<ILSMComponent> mergingComponents = ctx.getComponentHolder();
         LSMRTreeOpContext rctx = createOpContext(NoOpOperationCallback.INSTANCE);
-        rctx.getComponentHolder().addAll(mergingComponents);
-        ITreeIndexCursor cursor = new LSMRTreeWithAntiMatterTuplesSearchCursor(ctx);
-        ISearchPredicate rtreeSearchPred = new SearchPredicate(null, null);
-        search(rctx, cursor, (SearchPredicate) rtreeSearchPred);
         rctx.setOperation(IndexOperation.MERGE);
+        List<ILSMComponent> mergingComponents = ctx.getComponentHolder();
+        ITreeIndexCursor cursor = new LSMRTreeWithAntiMatterTuplesSearchCursor(rctx);
         LSMComponentFileReferences relMergeFileRefs = getMergeTargetFileName(mergingComponents);
         ILSMIndexAccessorInternal accessor = new LSMRTreeWithAntiMatterTuplesAccessor(lsmHarness, rctx);
         ioScheduler.scheduleOperation(new LSMRTreeMergeOperation(accessor, mergingComponents, cursor, relMergeFileRefs
@@ -310,21 +256,17 @@
     }
 
     @Override
-    public ILSMComponent merge(List<ILSMComponent> mergedComponents, ILSMIOOperation operation)
-            throws HyracksDataException, IndexException {
+    public ILSMComponent merge(ILSMIOOperation operation) throws HyracksDataException, IndexException {
         LSMRTreeMergeOperation mergeOp = (LSMRTreeMergeOperation) operation;
         ITreeIndexCursor cursor = mergeOp.getCursor();
-        mergedComponents.addAll(mergeOp.getMergingComponents());
-
-        // Nothing to merge.
-        if (mergedComponents.size() <= 1) {
-            cursor.close();
-            return null;
-        }
+        ISearchPredicate rtreeSearchPred = new SearchPredicate(null, null);
+        ILSMIndexOperationContext opCtx = ((LSMIndexSearchCursor) cursor).getOpCtx();
+        opCtx.getComponentHolder().addAll(mergeOp.getMergingComponents());
+        search(opCtx, cursor, rtreeSearchPred);
 
         // Bulk load the tuples from all on-disk RTrees into the new RTree.
-        LSMRTreeImmutableComponent component = createDiskComponent(componentFactory, mergeOp.getRTreeMergeTarget(),
-                null, null, true);
+        LSMRTreeDiskComponent component = createDiskComponent(componentFactory, mergeOp.getRTreeMergeTarget(), null,
+                null, true);
         RTree mergedRTree = component.getRTree();
         IIndexBulkLoader bulkloader = mergedRTree.createBulkLoader(1.0f, false, 0L, false);
         try {
@@ -358,7 +300,7 @@
 
         public MultiComparator getMultiComparator() {
             LSMRTreeOpContext concreteCtx = (LSMRTreeOpContext) ctx;
-            return concreteCtx.rtreeOpContext.cmp;
+            return concreteCtx.currentRTreeOpContext.cmp;
         }
     }
 
@@ -397,7 +339,7 @@
             } catch (HyracksDataException | IndexException e) {
                 throw new TreeIndexException(e);
             }
-            bulkLoader = ((LSMRTreeImmutableComponent) component).getRTree().createBulkLoader(fillFactor, verifyInput,
+            bulkLoader = ((LSMRTreeDiskComponent) component).getRTree().createBulkLoader(fillFactor, verifyInput,
                     numElementsHint, false);
         }
 
@@ -429,8 +371,8 @@
         protected void cleanupArtifacts() throws HyracksDataException {
             if (!cleanedUpArtifacts) {
                 cleanedUpArtifacts = true;
-                ((LSMRTreeImmutableComponent) component).getRTree().deactivate();
-                ((LSMRTreeImmutableComponent) component).getRTree().destroy();
+                ((LSMRTreeDiskComponent) component).getRTree().deactivate();
+                ((LSMRTreeDiskComponent) component).getRTree().destroy();
             }
         }
 
@@ -438,7 +380,7 @@
 
     @Override
     public void markAsValid(ILSMComponent lsmComponent) throws HyracksDataException {
-        RTree rtree = ((LSMRTreeImmutableComponent) lsmComponent).getRTree();
+        RTree rtree = ((LSMRTreeDiskComponent) lsmComponent).getRTree();
         forceFlushDirtyPages(rtree);
         markAsValidInternal(rtree);
     }
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuplesComponentFactory.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuplesDiskComponentFactory.java
similarity index 83%
rename from hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuplesComponentFactory.java
rename to hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuplesDiskComponentFactory.java
index 39f35b7..fe253cc 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuplesComponentFactory.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuplesDiskComponentFactory.java
@@ -23,16 +23,16 @@
 import edu.uci.ics.hyracks.storage.am.rtree.impls.RTree;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 
-public class LSMRTreeWithAntiMatterTuplesComponentFactory implements ILSMComponentFactory {
+public class LSMRTreeWithAntiMatterTuplesDiskComponentFactory implements ILSMComponentFactory {
     private final TreeIndexFactory<RTree> rtreeFactory;
 
-    public LSMRTreeWithAntiMatterTuplesComponentFactory(TreeIndexFactory<RTree> rtreeFactory) {
+    public LSMRTreeWithAntiMatterTuplesDiskComponentFactory(TreeIndexFactory<RTree> rtreeFactory) {
         this.rtreeFactory = rtreeFactory;
     }
 
     @Override
     public ILSMComponent createLSMComponentInstance(LSMComponentFileReferences cfr) throws IndexException {
-        return new LSMRTreeImmutableComponent(rtreeFactory.createIndexInstance(cfr.getInsertIndexFileReference()),
+        return new LSMRTreeDiskComponent(rtreeFactory.createIndexInstance(cfr.getInsertIndexFileReference()),
                 null, null);
     }
 
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuplesSearchCursor.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuplesSearchCursor.java
index c937709..cbaf3b3 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuplesSearchCursor.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuplesSearchCursor.java
@@ -18,6 +18,7 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
 import edu.uci.ics.hyracks.storage.am.btree.api.IBTreeLeafFrame;
+import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTreeRangeSearchCursor;
 import edu.uci.ics.hyracks.storage.am.btree.impls.RangePredicate;
 import edu.uci.ics.hyracks.storage.am.common.api.ICursorInitialState;
@@ -25,74 +26,133 @@
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexCursor;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent.LSMComponentType;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexOperationContext;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMIndexSearchCursor;
 import edu.uci.ics.hyracks.storage.am.rtree.api.IRTreeInteriorFrame;
 import edu.uci.ics.hyracks.storage.am.rtree.api.IRTreeLeafFrame;
+import edu.uci.ics.hyracks.storage.am.rtree.impls.RTree;
 import edu.uci.ics.hyracks.storage.am.rtree.impls.RTreeSearchCursor;
+import edu.uci.ics.hyracks.storage.am.rtree.impls.SearchPredicate;
 
 public class LSMRTreeWithAntiMatterTuplesSearchCursor extends LSMIndexSearchCursor {
 
-    private RTreeSearchCursor memRTreeCursor;
-    private BTreeRangeSearchCursor memBTreeCursor;
+    private ITreeIndexAccessor[] mutableRTreeAccessors;
+    private ITreeIndexAccessor[] btreeAccessors;
+    private RTreeSearchCursor[] mutableRTreeCursors;
+    private ITreeIndexCursor[] btreeCursors;
     private RangePredicate btreeRangePredicate;
-    private ITreeIndexAccessor memBTreeAccessor;
     private boolean foundNext;
     private ITupleReference frameTuple;
     private int[] comparatorFields;
     private MultiComparator btreeCmp;
+    private int currentCursor;
+    private SearchPredicate rtreeSearchPredicate;
+    private int numMutableComponents;
 
     public LSMRTreeWithAntiMatterTuplesSearchCursor(ILSMIndexOperationContext opCtx) {
         super(opCtx);
+        currentCursor = 0;
     }
 
     @Override
-    public void open(ICursorInitialState initialState, ISearchPredicate searchPred) throws HyracksDataException {
+    public void open(ICursorInitialState initialState, ISearchPredicate searchPred) throws HyracksDataException,
+            IndexException {
         LSMRTreeCursorInitialState lsmInitialState = (LSMRTreeCursorInitialState) initialState;
         cmp = lsmInitialState.getHilbertCmp();
         btreeCmp = lsmInitialState.getBTreeCmp();
-        int numDiskRTrees = lsmInitialState.getNumberOfTrees();
-        rangeCursors = new RTreeSearchCursor[numDiskRTrees];
-        for (int i = 0; i < numDiskRTrees; i++) {
-            rangeCursors[i] = new RTreeSearchCursor((IRTreeInteriorFrame) lsmInitialState
-                    .getRTreeInteriorFrameFactory().createFrame(), (IRTreeLeafFrame) lsmInitialState
-                    .getRTreeLeafFrameFactory().createFrame());
-        }
-        includeMemComponent = lsmInitialState.getIncludeMemComponent();
-        operationalComponents = lsmInitialState.getOperationalComponents();
-        if (includeMemComponent) {
-            memRTreeCursor = new RTreeSearchCursor((IRTreeInteriorFrame) lsmInitialState.getRTreeInteriorFrameFactory()
-                    .createFrame(), (IRTreeLeafFrame) lsmInitialState.getRTreeLeafFrameFactory().createFrame());
-            memBTreeCursor = new BTreeRangeSearchCursor((IBTreeLeafFrame) lsmInitialState.getBTreeLeafFrameFactory()
-                    .createFrame(), false);
-            memBTreeAccessor = lsmInitialState.getBTreeAccessors()[0];
-            btreeRangePredicate = new RangePredicate(null, null, true, true, btreeCmp, btreeCmp);
-        }
         lsmHarness = lsmInitialState.getLSMHarness();
         comparatorFields = lsmInitialState.getComparatorFields();
+        operationalComponents = lsmInitialState.getOperationalComponents();
+        rtreeSearchPredicate = (SearchPredicate) searchPred;
+
+        includeMutableComponent = false;
+        numMutableComponents = 0;
+        int numImmutableComponents = 0;
+        for (ILSMComponent component : operationalComponents) {
+            if (component.getType() == LSMComponentType.MEMORY) {
+                includeMutableComponent = true;
+                numMutableComponents++;
+            } else {
+                numImmutableComponents++;
+            }
+        }
+        if (includeMutableComponent) {
+            btreeRangePredicate = new RangePredicate(null, null, true, true, btreeCmp, btreeCmp);
+        }
+
+        mutableRTreeCursors = new RTreeSearchCursor[numMutableComponents];
+        mutableRTreeAccessors = new ITreeIndexAccessor[numMutableComponents];
+        btreeCursors = new BTreeRangeSearchCursor[numMutableComponents];
+        btreeAccessors = new ITreeIndexAccessor[numMutableComponents];
+        for (int i = 0; i < numMutableComponents; i++) {
+            ILSMComponent component = operationalComponents.get(i);
+            RTree rtree = (RTree) ((LSMRTreeMemoryComponent) component).getRTree();
+            BTree btree = (BTree) ((LSMRTreeMemoryComponent) component).getBTree();
+            mutableRTreeCursors[i] = new RTreeSearchCursor((IRTreeInteriorFrame) lsmInitialState
+                    .getRTreeInteriorFrameFactory().createFrame(), (IRTreeLeafFrame) lsmInitialState
+                    .getRTreeLeafFrameFactory().createFrame());
+            btreeCursors[i] = new BTreeRangeSearchCursor((IBTreeLeafFrame) lsmInitialState.getBTreeLeafFrameFactory()
+                    .createFrame(), false);
+            btreeAccessors[i] = btree.createAccessor(NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
+            mutableRTreeAccessors[i] = rtree.createAccessor(NoOpOperationCallback.INSTANCE,
+                    NoOpOperationCallback.INSTANCE);
+        }
+
+        rangeCursors = new RTreeSearchCursor[numImmutableComponents];
+        ITreeIndexAccessor[] immutableRTreeAccessors = new ITreeIndexAccessor[numImmutableComponents];
+        int j = 0;
+        for (int i = numMutableComponents; i < operationalComponents.size(); i++) {
+            ILSMComponent component = operationalComponents.get(i);
+            rangeCursors[j] = new RTreeSearchCursor((IRTreeInteriorFrame) lsmInitialState
+                    .getRTreeInteriorFrameFactory().createFrame(), (IRTreeLeafFrame) lsmInitialState
+                    .getRTreeLeafFrameFactory().createFrame());
+            RTree rtree = (RTree) ((LSMRTreeDiskComponent) component).getRTree();
+            immutableRTreeAccessors[j] = rtree.createAccessor(NoOpOperationCallback.INSTANCE,
+                    NoOpOperationCallback.INSTANCE);
+            immutableRTreeAccessors[j].search(rangeCursors[j], searchPred);
+            j++;
+        }
+        searchNextCursor();
         setPriorityQueueComparator();
+        initPriorityQueue();
+    }
+
+    private void searchNextCursor() throws HyracksDataException, IndexException {
+        if (currentCursor < numMutableComponents) {
+            mutableRTreeCursors[currentCursor].reset();
+            mutableRTreeAccessors[currentCursor].search(mutableRTreeCursors[currentCursor], rtreeSearchPredicate);
+        }
     }
 
     @Override
     public boolean hasNext() throws HyracksDataException, IndexException {
-        if (includeMemComponent) {
+        if (includeMutableComponent) {
             if (foundNext) {
                 return true;
             }
-            while (memRTreeCursor.hasNext()) {
-                memRTreeCursor.next();
-                ITupleReference memRTreeTuple = memRTreeCursor.getTuple();
-                if (searchMemBTree(memRTreeTuple)) {
-                    foundNext = true;
-                    frameTuple = memRTreeTuple;
-                    return true;
+
+            while (currentCursor < numMutableComponents) {
+                while (mutableRTreeCursors[currentCursor].hasNext()) {
+                    mutableRTreeCursors[currentCursor].next();
+                    ITupleReference currentTuple = mutableRTreeCursors[currentCursor].getTuple();
+                    if (searchMemBTrees(currentTuple, currentCursor)) {
+                        foundNext = true;
+                        frameTuple = currentTuple;
+                        return true;
+                    }
                 }
+                mutableRTreeCursors[currentCursor].close();
+                currentCursor++;
+                searchNextCursor();
             }
             while (super.hasNext()) {
                 super.next();
                 ITupleReference diskRTreeTuple = super.getTuple();
-                if (searchMemBTree(diskRTreeTuple)) {
+                if (searchMemBTrees(diskRTreeTuple, numMutableComponents - 1)) {
                     foundNext = true;
                     frameTuple = diskRTreeTuple;
                     return true;
@@ -107,7 +167,7 @@
 
     @Override
     public void next() throws HyracksDataException {
-        if (includeMemComponent) {
+        if (includeMutableComponent) {
             foundNext = false;
         } else {
             super.next();
@@ -117,7 +177,7 @@
 
     @Override
     public ITupleReference getTuple() {
-        if (includeMemComponent) {
+        if (includeMutableComponent) {
             return frameTuple;
         } else {
             return super.getTuple();
@@ -127,48 +187,49 @@
 
     @Override
     public void reset() throws HyracksDataException, IndexException {
-        if (includeMemComponent) {
-            memRTreeCursor.reset();
-            memBTreeCursor.reset();
+        if (includeMutableComponent) {
+            for (int i = 0; i < numMutableComponents; i++) {
+                mutableRTreeCursors[i].reset();
+                btreeCursors[i].reset();
+            }
         }
+        currentCursor = 0;
         super.reset();
     }
 
     @Override
     public void close() throws HyracksDataException {
-        if (includeMemComponent) {
-            memRTreeCursor.close();
-            memBTreeCursor.close();
+        if (includeMutableComponent) {
+            for (int i = 0; i < numMutableComponents; i++) {
+                mutableRTreeCursors[i].close();
+                btreeCursors[i].close();
+            }
         }
+        currentCursor = 0;
         super.close();
     }
 
-    public ITreeIndexCursor getMemRTreeCursor() {
-        return memRTreeCursor;
-    }
-
     @Override
     protected int compare(MultiComparator cmp, ITupleReference tupleA, ITupleReference tupleB) {
         return cmp.selectiveFieldCompare(tupleA, tupleB, comparatorFields);
     }
 
-    private boolean searchMemBTree(ITupleReference tuple) throws HyracksDataException {
-        try {
+    private boolean searchMemBTrees(ITupleReference tuple, int lastBTreeToSearch) throws HyracksDataException,
+            IndexException {
+        for (int i = 0; i <= lastBTreeToSearch; i++) {
+            btreeCursors[i].reset();
             btreeRangePredicate.setHighKey(tuple, true);
             btreeRangePredicate.setLowKey(tuple, true);
-            memBTreeAccessor.search(memBTreeCursor, btreeRangePredicate);
-        } catch (IndexException e) {
-            throw new HyracksDataException(e);
-        }
-        try {
-            if (memBTreeCursor.hasNext()) {
-                return false;
-            } else {
-                return true;
+            btreeAccessors[i].search(btreeCursors[i], btreeRangePredicate);
+            try {
+                if (btreeCursors[i].hasNext()) {
+                    return false;
+                }
+            } finally {
+                btreeCursors[i].close();
             }
-        } finally {
-            memBTreeCursor.close();
         }
+        return true;
     }
 
     @Override
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/utils/LSMRTreeUtils.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/utils/LSMRTreeUtils.java
index 50e5d09..ee942e7 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/utils/LSMRTreeUtils.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/utils/LSMRTreeUtils.java
@@ -15,6 +15,8 @@
 
 package edu.uci.ics.hyracks.storage.am.lsm.rtree.utils;
 
+import java.util.List;
+
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ILinearizeComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
@@ -31,7 +33,7 @@
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
 import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.freepage.LinkedListFreePageManagerFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexFileManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
@@ -58,12 +60,12 @@
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
 
 public class LSMRTreeUtils {
-    public static LSMRTree createLSMTree(IVirtualBufferCache virtualBufferCache, FileReference file,
+    public static LSMRTree createLSMTree(List<IVirtualBufferCache> virtualBufferCaches, FileReference file,
             IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ITypeTraits[] typeTraits,
             IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
+            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallback ioOpCallback,
             ILinearizeComparatorFactory linearizeCmpFactory) throws TreeIndexException {
         LSMTypeAwareTupleWriterFactory rtreeTupleWriterFactory = new LSMTypeAwareTupleWriterFactory(typeTraits, false);
         LSMTypeAwareTupleWriterFactory btreeTupleWriterFactory = new LSMTypeAwareTupleWriterFactory(typeTraits, true);
@@ -99,21 +101,21 @@
 
         ILSMIndexFileManager fileNameManager = new LSMRTreeFileManager(diskFileMapProvider, file, diskRTreeFactory,
                 diskBTreeFactory);
-        LSMRTree lsmTree = new LSMRTree(virtualBufferCache, rtreeInteriorFrameFactory, rtreeLeafFrameFactory,
+        LSMRTree lsmTree = new LSMRTree(virtualBufferCaches, rtreeInteriorFrameFactory, rtreeLeafFrameFactory,
                 btreeInteriorFrameFactory, btreeLeafFrameFactory, fileNameManager, diskRTreeFactory, diskBTreeFactory,
                 bloomFilterFactory, bloomFilterFalsePositiveRate, diskFileMapProvider, typeTraits.length,
                 rtreeCmpFactories, btreeCmpFactories, linearizeCmpFactory, comparatorFields, linearizerArray,
-                mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider);
+                mergePolicy, opTracker, ioScheduler, ioOpCallback);
         return lsmTree;
     }
 
     public static LSMRTreeWithAntiMatterTuples createLSMTreeWithAntiMatterTuples(
-            IVirtualBufferCache virtualBufferCache, FileReference file, IBufferCache diskBufferCache,
+            List<IVirtualBufferCache> virtualBufferCaches, FileReference file, IBufferCache diskBufferCache,
             IFileMapProvider diskFileMapProvider, ITypeTraits[] typeTraits,
             IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider, ILinearizeComparatorFactory linearizerCmpFactory)
+            ILSMIOOperationCallback ioOpCallback, ILinearizeComparatorFactory linearizerCmpFactory)
             throws TreeIndexException {
         LSMRTreeTupleWriterFactory rtreeTupleWriterFactory = new LSMRTreeTupleWriterFactory(typeTraits, false);
         LSMRTreeTupleWriterFactory btreeTupleWriterFactory = new LSMRTreeTupleWriterFactory(typeTraits, true);
@@ -151,11 +153,11 @@
 
         ILSMIndexFileManager fileNameManager = new LSMRTreeWithAntiMatterTuplesFileManager(diskFileMapProvider, file,
                 diskRTreeFactory);
-        LSMRTreeWithAntiMatterTuples lsmTree = new LSMRTreeWithAntiMatterTuples(virtualBufferCache,
+        LSMRTreeWithAntiMatterTuples lsmTree = new LSMRTreeWithAntiMatterTuples(virtualBufferCaches,
                 rtreeInteriorFrameFactory, rtreeLeafFrameFactory, btreeInteriorFrameFactory, btreeLeafFrameFactory,
                 fileNameManager, diskRTreeFactory, bulkLoadRTreeFactory, diskFileMapProvider, typeTraits.length,
                 rtreeCmpFactories, btreeCmpFactories, linearizerCmpFactory, comparatorFields, linearizerArray,
-                mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider);
+                mergePolicy, opTracker, ioScheduler, ioOpCallback);
         return lsmTree;
     }
 
diff --git a/hyracks/hyracks-storage-am-rtree/pom.xml b/hyracks/hyracks-storage-am-rtree/pom.xml
index edbf803..410ed6f 100644
--- a/hyracks/hyracks-storage-am-rtree/pom.xml
+++ b/hyracks/hyracks-storage-am-rtree/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -41,21 +41,21 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-common</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-dataflow-common</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-dataflow-std</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
diff --git a/hyracks/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/impls/RTree.java b/hyracks/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/impls/RTree.java
index 528c004..7bb3583 100644
--- a/hyracks/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/impls/RTree.java
+++ b/hyracks/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/impls/RTree.java
@@ -147,7 +147,7 @@
     private RTreeOpContext createOpContext(IModificationOperationCallback modificationCallback) {
         return new RTreeOpContext((IRTreeLeafFrame) leafFrameFactory.createFrame(),
                 (IRTreeInteriorFrame) interiorFrameFactory.createFrame(), freePageManager.getMetaDataFrameFactory()
-                        .createFrame(), cmpFactories, 8, modificationCallback);
+                        .createFrame(), cmpFactories, modificationCallback);
     }
 
     private void insert(ITupleReference tuple, IIndexOperationContext ictx) throws HyracksDataException,
diff --git a/hyracks/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/impls/RTreeOpContext.java b/hyracks/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/impls/RTreeOpContext.java
index da73f85..a9171c3 100644
--- a/hyracks/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/impls/RTreeOpContext.java
+++ b/hyracks/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/impls/RTreeOpContext.java
@@ -31,6 +31,7 @@
 
 public class RTreeOpContext implements IIndexOperationContext {
     private static final int INITIAL_TRAVERSE_LIST_SIZE = 100;
+    private static final int INITIAL_HEIGHT = 8;
     public final MultiComparator cmp;
     public final IRTreeInteriorFrame interiorFrame;
     public final IRTreeLeafFrame leafFrame;
@@ -51,20 +52,20 @@
     public final IModificationOperationCallback modificationCallback;
 
     public RTreeOpContext(IRTreeLeafFrame leafFrame, IRTreeInteriorFrame interiorFrame,
-            ITreeIndexMetaDataFrame metaFrame, IBinaryComparatorFactory[] cmpFactories, int treeHeightHint,
+            ITreeIndexMetaDataFrame metaFrame, IBinaryComparatorFactory[] cmpFactories,
             IModificationOperationCallback modificationCallback) {
-        
-        if (cmpFactories[0] != null) { 
+
+        if (cmpFactories[0] != null) {
             this.cmp = MultiComparator.create(cmpFactories);
         } else {
             this.cmp = null;
         }
-        
+
         this.interiorFrame = interiorFrame;
         this.leafFrame = leafFrame;
         this.metaFrame = metaFrame;
         this.modificationCallback = modificationCallback;
-        pathList = new PathList(treeHeightHint, treeHeightHint);
+        pathList = new PathList(INITIAL_HEIGHT, INITIAL_HEIGHT);
         NSNUpdates = new ArrayList<ICachedPage>();
         LSNUpdates = new ArrayList<ICachedPage>();
     }
diff --git a/hyracks/hyracks-storage-common/pom.xml b/hyracks/hyracks-storage-common/pom.xml
index 519320f..349c223 100644
--- a/hyracks/hyracks-storage-common/pom.xml
+++ b/hyracks/hyracks-storage-common/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -41,7 +41,7 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-api</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
diff --git a/hyracks/hyracks-test-support/pom.xml b/hyracks/hyracks-test-support/pom.xml
index bc00394..d2e1697 100644
--- a/hyracks/hyracks-test-support/pom.xml
+++ b/hyracks/hyracks-test-support/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -41,33 +41,33 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-control-nc</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-common</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-btree</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-rtree</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-lsm-invertedindex</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
diff --git a/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/btree/OrderedIndexExamplesTest.java b/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/btree/OrderedIndexExamplesTest.java
index eafeff2..0a70185 100644
--- a/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/btree/OrderedIndexExamplesTest.java
+++ b/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/btree/OrderedIndexExamplesTest.java
@@ -46,6 +46,7 @@
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexCursor;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
 import edu.uci.ics.hyracks.storage.am.common.api.UnsortedInputException;
+import edu.uci.ics.hyracks.storage.am.common.exceptions.TreeIndexDuplicateKeyException;
 import edu.uci.ics.hyracks.storage.am.common.impls.TreeIndexDiskOrderScanCursor;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
 
@@ -140,9 +141,9 @@
 
     /**
      * This test the btree page split. Originally this test didn't pass since
-     * the btree was spliting by cardinality and not size. Thus, we might end
-     * up with a situation where there is not enough space to insert the new
-     * tuple after the split which will throw an error and the split won't be
+     * the btree was spliting by cardinality and not size. Thus, we might end up
+     * with a situation where there is not enough space to insert the new tuple
+     * after the split which will throw an error and the split won't be
      * propagated to upper level; thus, the tree is corrupted. Now, it split
      * page by size. The correct behavior on abnormally large keys/values.
      */
@@ -716,6 +717,12 @@
                     }
                     // Success.
                     break;
+                } catch (TreeIndexDuplicateKeyException e2) {
+                    if (j != i) {
+                        fail("Unexpected exception: " + e2.getMessage());
+                    }
+                    // Success.
+                    break;
                 }
             }
 
diff --git a/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/btree/OrderedIndexTestUtils.java b/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/btree/OrderedIndexTestUtils.java
index 5b7b050..9de217b 100644
--- a/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/btree/OrderedIndexTestUtils.java
+++ b/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/btree/OrderedIndexTestUtils.java
@@ -35,7 +35,6 @@
 import edu.uci.ics.hyracks.dataflow.common.data.marshalling.IntegerSerializerDeserializer;
 import edu.uci.ics.hyracks.dataflow.common.data.marshalling.UTF8StringSerializerDeserializer;
 import edu.uci.ics.hyracks.dataflow.common.util.TupleUtils;
-import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeDuplicateKeyException;
 import edu.uci.ics.hyracks.storage.am.btree.impls.RangePredicate;
 import edu.uci.ics.hyracks.storage.am.btree.util.BTreeUtils;
 import edu.uci.ics.hyracks.storage.am.common.CheckTuple;
@@ -44,6 +43,7 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexCursor;
 import edu.uci.ics.hyracks.storage.am.common.api.ISearchPredicate;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexCursor;
+import edu.uci.ics.hyracks.storage.am.common.exceptions.TreeIndexDuplicateKeyException;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
 
 @SuppressWarnings("rawtypes")
@@ -205,7 +205,7 @@
                 // Set expected values. Do this only after insertion succeeds
                 // because we ignore duplicate keys.
                 ctx.insertCheckTuple(createStringCheckTuple(fieldValues, ctx.getKeyFieldCount()), ctx.getCheckTuples());
-            } catch (BTreeDuplicateKeyException e) {
+            } catch (TreeIndexDuplicateKeyException e) {
                 // Ignore duplicate key insertions.
             }
         }
diff --git a/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/config/AccessMethodTestsConfig.java b/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/config/AccessMethodTestsConfig.java
index 693dc47..6e1995c 100644
--- a/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/config/AccessMethodTestsConfig.java
+++ b/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/config/AccessMethodTestsConfig.java
@@ -29,6 +29,7 @@
     public static final int LSM_RTREE_BULKLOAD_ROUNDS = 5;
     public static final int LSM_RTREE_MAX_TREES_TO_MERGE = 3;
     public static final boolean LSM_RTREE_TEST_RSTAR_POLICY = false;
+    public static final int LSM_RTREE_NUM_MUTABLE_COMPONENTS = 2;
 
     // Test params for BTree, LSMBTree.
     public static final int BTREE_NUM_TUPLES_TO_INSERT = 100;
@@ -39,17 +40,18 @@
     // Test params for LSMBTree only.
     public static final int LSM_BTREE_BULKLOAD_ROUNDS = 5;
     public static final int LSM_BTREE_MAX_TREES_TO_MERGE = 10;
+    public static final int LSM_BTREE_NUM_MUTABLE_COMPONENTS = 2;
 
     // Mem configuration for RTree.
     public static final int RTREE_PAGE_SIZE = 512;
     public static final int RTREE_NUM_PAGES = 1000;
-    public static final int RTREE_MAX_OPEN_FILES = 10;
+    public static final int RTREE_MAX_OPEN_FILES = Integer.MAX_VALUE;
     public static final int RTREE_HYRACKS_FRAME_SIZE = 128;
 
     // Mem configuration for LSMRTree and LSMRTreeWithAntiMatterTuples.
     public static final int LSM_RTREE_DISK_PAGE_SIZE = 512;
     public static final int LSM_RTREE_DISK_NUM_PAGES = 1000;
-    public static final int LSM_RTREE_DISK_MAX_OPEN_FILES = 2000;
+    public static final int LSM_RTREE_DISK_MAX_OPEN_FILES = Integer.MAX_VALUE;
     public static final int LSM_RTREE_MEM_PAGE_SIZE = 512;
     public static final int LSM_RTREE_MEM_NUM_PAGES = 1000;
     public static final int LSM_RTREE_HYRACKS_FRAME_SIZE = 128;
@@ -58,13 +60,13 @@
     // Mem configuration for BTree.
     public static final int BTREE_PAGE_SIZE = 256;
     public static final int BTREE_NUM_PAGES = 100;
-    public static final int BTREE_MAX_OPEN_FILES = 10;
+    public static final int BTREE_MAX_OPEN_FILES = Integer.MAX_VALUE;
     public static final int BTREE_HYRACKS_FRAME_SIZE = 128;
 
     // Mem configuration for LSMBTree.
     public static final int LSM_BTREE_DISK_PAGE_SIZE = 256;
     public static final int LSM_BTREE_DISK_NUM_PAGES = 1000;
-    public static final int LSM_BTREE_DISK_MAX_OPEN_FILES = 200;
+    public static final int LSM_BTREE_DISK_MAX_OPEN_FILES = Integer.MAX_VALUE;
     public static final int LSM_BTREE_MEM_PAGE_SIZE = 256;
     public static final int LSM_BTREE_MEM_NUM_PAGES = 100;
     public static final int LSM_BTREE_HYRACKS_FRAME_SIZE = 128;
@@ -73,11 +75,13 @@
     // Mem configuration for Inverted Index.
     public static final int LSM_INVINDEX_DISK_PAGE_SIZE = 1024;
     public static final int LSM_INVINDEX_DISK_NUM_PAGES = 1000;
-    public static final int LSM_INVINDEX_DISK_MAX_OPEN_FILES = 1000;
+    public static final int LSM_INVINDEX_DISK_MAX_OPEN_FILES = Integer.MAX_VALUE;
     public static final int LSM_INVINDEX_MEM_PAGE_SIZE = 1024;
     public static final int LSM_INVINDEX_MEM_NUM_PAGES = 100;
     public static final int LSM_INVINDEX_HYRACKS_FRAME_SIZE = 32768;
     public static final double LSM_INVINDEX_BLOOMFILTER_FALSE_POSITIVE_RATE = 0.01;
+    public static final int LSM_INVINDEX_NUM_MUTABLE_COMPONENTS = 2;
+
     // Test parameters.
     public static final int LSM_INVINDEX_NUM_DOCS_TO_INSERT = 100;
     // Used for full-fledged search test.
@@ -100,7 +104,7 @@
     // Mem configuration for BloomFilter.
     public static final int BLOOM_FILTER_PAGE_SIZE = 256;
     public static final int BLOOM_FILTER_NUM_PAGES = 1000;
-    public static final int BLOOM_FILTER_MAX_OPEN_FILES = 10;
+    public static final int BLOOM_FILTER_MAX_OPEN_FILES = Integer.MAX_VALUE;
     public static final int BLOOM_FILTER_HYRACKS_FRAME_SIZE = 128;
 
 }
@@ -111,9 +115,12 @@
 public static final int RTREE_NUM_INSERT_ROUNDS = 2;
 public static final int RTREE_NUM_DELETE_ROUNDS = 2;
 public static final int RTREE_MULTITHREAD_NUM_OPERATIONS = 10000;
+public static final boolean RTREE_TEST_RSTAR_POLICY = true;
 // Test params for LSMRTree and LSMRTreeWithAntiMatterTuples.
 public static final int LSM_RTREE_BULKLOAD_ROUNDS = 5;
+public static final boolean LSM_RTREE_TEST_RSTAR_POLICY = false;
 public static final int LSM_RTREE_MAX_TREES_TO_MERGE = 3;	
+public static final int LSM_RTREE_NUM_MUTABLE_COMPONENTS = 2;
 
 // Test params for BTree, LSMBTree.
 public static final int BTREE_NUM_TUPLES_TO_INSERT = 10000;
@@ -124,46 +131,51 @@
 // Test params for LSMBTree only.
 public static final int LSM_BTREE_BULKLOAD_ROUNDS = 5;
 public static final int LSM_BTREE_MAX_TREES_TO_MERGE = 10;
+public static final int LSM_BTREE_NUM_MUTABLE_COMPONENTS = 2;
 	
 	
 // Mem configuration for RTree.
 public static final int RTREE_PAGE_SIZE = 512;
 public static final int RTREE_NUM_PAGES = 1000;
-public static final int RTREE_MAX_OPEN_FILES = 10;
+public static final int RTREE_MAX_OPEN_FILES = Integer.MAX_VALUE;
 public static final int RTREE_HYRACKS_FRAME_SIZE = 128;
 	
 // Mem configuration for LSMRTree and LSMRTreeWithAntiMatterTuples.
-public static final int LSM_RTREE_DISK_PAGE_SIZE = 256;
-public static final int LSM_RTREE_DISK_NUM_PAGES = 1000;
-public static final int LSM_RTREE_DISK_MAX_OPEN_FILES = 2000;
-public static final int LSM_RTREE_MEM_PAGE_SIZE = 256;
+public static final int LSM_RTREE_DISK_PAGE_SIZE = 512;
+public static final int LSM_RTREE_DISK_NUM_PAGES = 10000;
+public static final int LSM_RTREE_DISK_MAX_OPEN_FILES = Integer.MAX_VALUE;
+public static final int LSM_RTREE_MEM_PAGE_SIZE = 512;
 public static final int LSM_RTREE_MEM_NUM_PAGES = 1000;
 public static final int LSM_RTREE_HYRACKS_FRAME_SIZE = 128;
+public static final double LSM_RTREE_BLOOMFILTER_FALSE_POSITIVE_RATE = 0.01;
 	
 // Mem configuration for BTree.
 public static final int BTREE_PAGE_SIZE = 256;
 public static final int BTREE_NUM_PAGES = 100;
-public static final int BTREE_MAX_OPEN_FILES = 10;
+public static final int BTREE_MAX_OPEN_FILES = Integer.MAX_VALUE;
 public static final int BTREE_HYRACKS_FRAME_SIZE = 128;
 	
 // Mem configuration for LSMBTree.
 public static final int LSM_BTREE_DISK_PAGE_SIZE = 256;
-public static final int LSM_BTREE_DISK_NUM_PAGES = 1000;
-public static final int LSM_BTREE_DISK_MAX_OPEN_FILES = 200;
+public static final int LSM_BTREE_DISK_NUM_PAGES = 10000;
+public static final int LSM_BTREE_DISK_MAX_OPEN_FILES = Integer.MAX_VALUE;
 public static final int LSM_BTREE_MEM_PAGE_SIZE = 256;
 public static final int LSM_BTREE_MEM_NUM_PAGES = 100;
 public static final int LSM_BTREE_HYRACKS_FRAME_SIZE = 128;
+public static final double LSM_BTREE_BLOOMFILTER_FALSE_POSITIVE_RATE = 0.01;
 
 // Mem configuration for Inverted Index.
 public static final int INVINDEX_PAGE_SIZE = 32768;
 public static final int INVINDEX_NUM_PAGES = 100;
-public static final int INVINDEX_MAX_OPEN_FILES = 10;
+public static final int INVINDEX_MAX_OPEN_FILES = Integer.MAX_VALUE;
 public static final int INVINDEX_HYRACKS_FRAME_SIZE = 32768;
+public static final double LSM_INVINDEX_BLOOMFILTER_FALSE_POSITIVE_RATE = 0.01;
+public static final int LSM_INVINDEX_NUM_MUTABLE_COMPONENTS = 2;
 
 // Mem configuration for Inverted Index.
 public static final int LSM_INVINDEX_DISK_PAGE_SIZE = 1024;
-public static final int LSM_INVINDEX_DISK_NUM_PAGES = 1000;
-public static final int LSM_INVINDEX_DISK_MAX_OPEN_FILES = 1000;
+public static final int LSM_INVINDEX_DISK_NUM_PAGES = 10000;
+public static final int LSM_INVINDEX_DISK_MAX_OPEN_FILES = Integer.MAX_VALUE;
 public static final int LSM_INVINDEX_MEM_PAGE_SIZE = 1024;
 public static final int LSM_INVINDEX_MEM_NUM_PAGES = 100;
 public static final int LSM_INVINDEX_HYRACKS_FRAME_SIZE = 32768;
@@ -182,4 +194,13 @@
 // Allocate a generous size to make sure we have enough elements for all tests.
 public static final int LSM_INVINDEX_SCAN_COUNT_ARRAY_SIZE = 1000000;
 public static final int LSM_INVINDEX_MULTITHREAD_NUM_OPERATIONS = 10000;
+
+// Test params for BloomFilter
+public static final int BLOOM_FILTER_NUM_TUPLES_TO_INSERT = 10000;
+
+// Mem configuration for BloomFilter.
+public static final int BLOOM_FILTER_PAGE_SIZE = 256;
+public static final int BLOOM_FILTER_NUM_PAGES = 1000;
+public static final int BLOOM_FILTER_MAX_OPEN_FILES = Integer.MAX_VALUE;
+public static final int BLOOM_FILTER_HYRACKS_FRAME_SIZE = 128;
 */
diff --git a/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/AbstractRTreeExamplesTest.java b/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/AbstractRTreeExamplesTest.java
index 44ab0d9..705a976 100644
--- a/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/AbstractRTreeExamplesTest.java
+++ b/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/AbstractRTreeExamplesTest.java
@@ -134,12 +134,6 @@
 
             TupleUtils.createIntegerTuple(tb, tuple, Math.min(p1x, p2x), Math.min(p1y, p2y), Math.max(p1x, p2x),
                     Math.max(p1y, p2y), pk1, pk2);
-            if (LOGGER.isLoggable(Level.INFO)) {
-                if (i % 1000 == 0) {
-                    LOGGER.info("Inserting " + i + " " + Math.min(p1x, p2x) + " " + Math.min(p1y, p2y) + " "
-                            + Math.max(p1x, p2x) + " " + Math.max(p1y, p2y) + ", " + pk1 + ", " + pk2);
-                }
-            }
             try {
                 indexAccessor.insert(tuple);
             } catch (TreeIndexException e) {
@@ -494,13 +488,6 @@
 
             TupleUtils.createDoubleTuple(tb, tuple, Math.min(p1x, p2x), Math.min(p1y, p2y), Math.min(p1z, p2z),
                     Math.max(p1x, p2x), Math.max(p1y, p2y), Math.max(p1z, p2z), pk);
-            if (LOGGER.isLoggable(Level.INFO)) {
-                if (i % 1000 == 0) {
-                    LOGGER.info("Inserting " + i + " " + Math.min(p1x, p2x) + " " + Math.min(p1y, p2y) + " "
-                            + Math.min(p1z, p2z) + " " + Math.max(p1x, p2x) + " " + Math.max(p1y, p2y) + " "
-                            + Math.max(p1z, p2z) + ", " + pk);
-                }
-            }
             try {
                 indexAccessor.insert(tuple);
             } catch (TreeIndexException e) {
@@ -608,11 +595,6 @@
 
                 TupleUtils.createIntegerTuple(tb, tuple, Math.min(p1x, p2x), Math.min(p1y, p2y), Math.max(p1x, p2x),
                         Math.max(p1y, p2y), pk);
-                if (LOGGER.isLoggable(Level.INFO)) {
-                    if (i % 1000 == 0) {
-                        LOGGER.info("Inserting " + i);
-                    }
-                }
                 try {
                     indexAccessor.insert(tuple);
                 } catch (TreeIndexException e) {
@@ -626,11 +608,6 @@
             int delDone = 0;
             for (int i = 0; i < numInserts; i++) {
                 TupleUtils.createIntegerTuple(tb, tuple, p1xs[i], p1ys[i], p2xs[i], p2ys[i], pks[i]);
-                if (LOGGER.isLoggable(Level.INFO)) {
-                    if (i % 1000 == 0) {
-                        LOGGER.info("Deleting " + i);
-                    }
-                }
                 try {
                     indexAccessor.delete(tuple);
                     delDone++;
diff --git a/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestVirtualBufferCacheProvider.java b/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestVirtualBufferCacheProvider.java
index 9db21cb..afbb86b 100644
--- a/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestVirtualBufferCacheProvider.java
+++ b/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestVirtualBufferCacheProvider.java
@@ -14,6 +14,9 @@
  */
 package edu.uci.ics.hyracks.test.support;
 
+import java.util.ArrayList;
+import java.util.List;
+
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCacheProvider;
@@ -33,7 +36,12 @@
     }
 
     @Override
-    public IVirtualBufferCache getVirtualBufferCache(IHyracksTaskContext ctx) {
-        return new VirtualBufferCache(new HeapBufferAllocator(), pageSize, numPages);
+    public List<IVirtualBufferCache> getVirtualBufferCaches(IHyracksTaskContext ctx) {
+        List<IVirtualBufferCache> vbcs = new ArrayList<IVirtualBufferCache>();
+        for (int i = 0; i < 2; i++) {
+            IVirtualBufferCache vbc = new VirtualBufferCache(new HeapBufferAllocator(), pageSize, numPages / 2);
+            vbcs.add(vbc);
+        }
+        return vbcs;
     }
 }
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-bloomfilter-test/pom.xml b/hyracks/hyracks-tests/hyracks-storage-am-bloomfilter-test/pom.xml
index 09f7302..cacd829 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-bloomfilter-test/pom.xml
+++ b/hyracks/hyracks-tests/hyracks-storage-am-bloomfilter-test/pom.xml
@@ -19,7 +19,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks-tests</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -46,14 +46,14 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-bloomfilter</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-test-support</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>test</scope>
   	</dependency>
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-btree-test/pom.xml b/hyracks/hyracks-tests/hyracks-storage-am-btree-test/pom.xml
index b363aac..6fa8414 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-btree-test/pom.xml
+++ b/hyracks/hyracks-tests/hyracks-storage-am-btree-test/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks-tests</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -48,14 +48,14 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-btree</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-test-support</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>test</scope>
   	</dependency>
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/multithread/BTreeTestWorker.java b/hyracks/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/multithread/BTreeTestWorker.java
index 262e21c..22d3e6a 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/multithread/BTreeTestWorker.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/multithread/BTreeTestWorker.java
@@ -19,8 +19,6 @@
 import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleReference;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
-import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeDuplicateKeyException;
-import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeNonExistentKeyException;
 import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeNotUpdateableException;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
 import edu.uci.ics.hyracks.storage.am.btree.impls.RangePredicate;
@@ -31,6 +29,8 @@
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexCursor;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 import edu.uci.ics.hyracks.storage.am.common.datagen.DataGenThread;
+import edu.uci.ics.hyracks.storage.am.common.exceptions.TreeIndexDuplicateKeyException;
+import edu.uci.ics.hyracks.storage.am.common.exceptions.TreeIndexNonExistentKeyException;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
 
 public class BTreeTestWorker extends AbstractIndexTestWorker {
@@ -60,7 +60,7 @@
             case INSERT:
                 try {
                     accessor.insert(tuple);
-                } catch (BTreeDuplicateKeyException e) {
+                } catch (TreeIndexDuplicateKeyException e) {
                     // Ignore duplicate keys, since we get random tuples.
                 }
                 break;
@@ -74,7 +74,7 @@
                 deleteTuple.reset(deleteTb.getFieldEndOffsets(), deleteTb.getByteArray());
                 try {
                     accessor.delete(deleteTuple);
-                } catch (BTreeNonExistentKeyException e) {
+                } catch (TreeIndexNonExistentKeyException e) {
                     // Ignore non-existant keys, since we get random tuples.
                 }
                 break;
@@ -82,7 +82,7 @@
             case UPDATE:
                 try {
                     accessor.update(tuple);
-                } catch (BTreeNonExistentKeyException e) {
+                } catch (TreeIndexNonExistentKeyException e) {
                     // Ignore non-existant keys, since we get random tuples.
                 } catch (BTreeNotUpdateableException e) {
                     // Ignore not updateable exception due to numKeys == numFields.
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/pom.xml b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/pom.xml
index 466af51..83d382c 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/pom.xml
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/pom.xml
@@ -19,7 +19,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks-tests</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -39,20 +39,20 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-lsm-btree</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>  	
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-common</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-test-support</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<scope>compile</scope>
   	</dependency>
   </dependencies>
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeBulkLoadTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeBulkLoadTest.java
index e0a2a46..447c507 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeBulkLoadTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeBulkLoadTest.java
@@ -51,10 +51,10 @@
     @Override
     protected OrderedIndexTestContext createTestContext(ISerializerDeserializer[] fieldSerdes, int numKeys,
             BTreeLeafFrameType leafType) throws Exception {
-        return LSMBTreeTestContext.create(harness.getVirtualBufferCache(), harness.getFileReference(),
+        return LSMBTreeTestContext.create(harness.getVirtualBufferCaches(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, numKeys,
                 harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(), harness.getOperationTracker(),
-                harness.getIOScheduler(), harness.getIOOperationCallbackProvider());
+                harness.getIOScheduler(), harness.getIOOperationCallback());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeDeleteTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeDeleteTest.java
index 122b788..0303dbd 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeDeleteTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeDeleteTest.java
@@ -51,10 +51,10 @@
     @Override
     protected OrderedIndexTestContext createTestContext(ISerializerDeserializer[] fieldSerdes, int numKeys,
             BTreeLeafFrameType leafType) throws Exception {
-        return LSMBTreeTestContext.create(harness.getVirtualBufferCache(), harness.getFileReference(),
+        return LSMBTreeTestContext.create(harness.getVirtualBufferCaches(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, numKeys,
                 harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(), harness.getOperationTracker(),
-                harness.getIOScheduler(), harness.getIOOperationCallbackProvider());
+                harness.getIOScheduler(), harness.getIOOperationCallback());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeExamplesTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeExamplesTest.java
index 60e0492..dc55f5d 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeExamplesTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeExamplesTest.java
@@ -34,10 +34,10 @@
     @Override
     protected ITreeIndex createTreeIndex(ITypeTraits[] typeTraits, IBinaryComparatorFactory[] cmpFactories,
             int[] bloomFilterKeyFields) throws TreeIndexException {
-        return LSMBTreeUtils.createLSMTree(harness.getVirtualBufferCache(), harness.getFileReference(),
+        return LSMBTreeUtils.createLSMTree(harness.getVirtualBufferCaches(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), typeTraits, cmpFactories,
                 bloomFilterKeyFields, harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
-                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallbackProvider());
+                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallback());
     }
 
     @Before
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeInsertTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeInsertTest.java
index 76a0206..4fc3960 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeInsertTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeInsertTest.java
@@ -51,10 +51,10 @@
     @Override
     protected OrderedIndexTestContext createTestContext(ISerializerDeserializer[] fieldSerdes, int numKeys,
             BTreeLeafFrameType leafType) throws Exception {
-        return LSMBTreeTestContext.create(harness.getVirtualBufferCache(), harness.getFileReference(),
+        return LSMBTreeTestContext.create(harness.getVirtualBufferCaches(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, numKeys,
                 harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(), harness.getOperationTracker(),
-                harness.getIOScheduler(), harness.getIOOperationCallbackProvider());
+                harness.getIOScheduler(), harness.getIOOperationCallback());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeLifecycleTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeLifecycleTest.java
index 639fd47..f553b72 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeLifecycleTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeLifecycleTest.java
@@ -53,10 +53,10 @@
     @Override
     public void setup() throws Exception {
         harness.setUp();
-        testCtx = LSMBTreeTestContext.create(harness.getVirtualBufferCache(), harness.getFileReference(),
+        testCtx = LSMBTreeTestContext.create(harness.getVirtualBufferCaches(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, fieldSerdes.length,
                 harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(), harness.getOperationTracker(),
-                harness.getIOScheduler(), harness.getIOOperationCallbackProvider());
+                harness.getIOScheduler(), harness.getIOOperationCallback());
         index = testCtx.getIndex();
     }
 
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMergeTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMergeTest.java
index e3c86df..f5cfb32 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMergeTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMergeTest.java
@@ -50,10 +50,10 @@
     @Override
     protected OrderedIndexTestContext createTestContext(ISerializerDeserializer[] fieldSerdes, int numKeys,
             BTreeLeafFrameType leafType) throws Exception {
-        return LSMBTreeTestContext.create(harness.getVirtualBufferCache(), harness.getFileReference(),
+        return LSMBTreeTestContext.create(harness.getVirtualBufferCaches(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, numKeys,
                 harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(), harness.getOperationTracker(),
-                harness.getIOScheduler(), harness.getIOOperationCallbackProvider());
+                harness.getIOScheduler(), harness.getIOOperationCallback());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeModificationOperationCallbackTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeModificationOperationCallbackTest.java
index 77b65ca..2234075 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeModificationOperationCallbackTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeModificationOperationCallbackTest.java
@@ -42,13 +42,13 @@
 
     @Override
     protected void createIndexInstance() throws Exception {
-        index = LSMBTreeUtils.createLSMTree(harness.getVirtualBufferCache(), harness.getFileReference(),
+        index = LSMBTreeUtils.createLSMTree(harness.getVirtualBufferCaches(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
                 SerdeUtils.serdesToTypeTraits(keySerdes),
                 SerdeUtils.serdesToComparatorFactories(keySerdes, keySerdes.length), bloomFilterKeyFields,
                 harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
                 NoOpOperationTrackerProvider.INSTANCE.getOperationTracker(null), harness.getIOScheduler(),
-                harness.getIOOperationCallbackProvider());
+                harness.getIOOperationCallback());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMultiBulkLoadTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMultiBulkLoadTest.java
index a7c8b81..277df6b 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMultiBulkLoadTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMultiBulkLoadTest.java
@@ -52,10 +52,10 @@
     @Override
     protected OrderedIndexTestContext createTestContext(ISerializerDeserializer[] fieldSerdes, int numKeys,
             BTreeLeafFrameType leafType) throws Exception {
-        return LSMBTreeTestContext.create(harness.getVirtualBufferCache(), harness.getFileReference(),
+        return LSMBTreeTestContext.create(harness.getVirtualBufferCaches(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, numKeys,
                 harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(), harness.getOperationTracker(),
-                harness.getIOScheduler(), harness.getIOOperationCallbackProvider());
+                harness.getIOScheduler(), harness.getIOOperationCallback());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeSearchOperationCallbackTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeSearchOperationCallbackTest.java
index e15e80a..f1a5355 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeSearchOperationCallbackTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeSearchOperationCallbackTest.java
@@ -49,13 +49,13 @@
 
     @Override
     protected void createIndexInstance() throws Exception {
-        index = LSMBTreeUtils.createLSMTree(harness.getVirtualBufferCache(), harness.getFileReference(),
+        index = LSMBTreeUtils.createLSMTree(harness.getVirtualBufferCaches(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
                 SerdeUtils.serdesToTypeTraits(keySerdes),
                 SerdeUtils.serdesToComparatorFactories(keySerdes, keySerdes.length), bloomFilterKeyFields,
                 harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
                 NoOpOperationTrackerProvider.INSTANCE.getOperationTracker(null), harness.getIOScheduler(),
-                harness.getIOOperationCallbackProvider());
+                harness.getIOOperationCallback());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeUpdateTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeUpdateTest.java
index db221a2..a5097b4 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeUpdateTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeUpdateTest.java
@@ -51,10 +51,10 @@
     @Override
     protected OrderedIndexTestContext createTestContext(ISerializerDeserializer[] fieldSerdes, int numKeys,
             BTreeLeafFrameType leafType) throws Exception {
-        return LSMBTreeTestContext.create(harness.getVirtualBufferCache(), harness.getFileReference(),
+        return LSMBTreeTestContext.create(harness.getVirtualBufferCaches(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, numKeys,
                 harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(), harness.getOperationTracker(),
-                harness.getIOScheduler(), harness.getIOOperationCallbackProvider());
+                harness.getIOScheduler(), harness.getIOOperationCallback());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeMultiThreadTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeMultiThreadTest.java
index 9dfa713..adee618 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeMultiThreadTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeMultiThreadTest.java
@@ -50,10 +50,10 @@
     @Override
     protected ITreeIndex createIndex(ITypeTraits[] typeTraits, IBinaryComparatorFactory[] cmpFactories,
             int[] bloomFilterKeyFields) throws TreeIndexException {
-        return LSMBTreeUtils.createLSMTree(harness.getVirtualBufferCache(), harness.getFileReference(),
+        return LSMBTreeUtils.createLSMTree(harness.getVirtualBufferCaches(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), typeTraits, cmpFactories,
                 bloomFilterKeyFields, harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
-                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallbackProvider());
+                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallback());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeTestWorker.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeTestWorker.java
index 8a37b4e..4a96131 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeTestWorker.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeTestWorker.java
@@ -19,8 +19,6 @@
 import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleReference;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
-import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeDuplicateKeyException;
-import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeNonExistentKeyException;
 import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeNotUpdateableException;
 import edu.uci.ics.hyracks.storage.am.btree.impls.RangePredicate;
 import edu.uci.ics.hyracks.storage.am.common.AbstractIndexTestWorker;
@@ -30,6 +28,8 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexCursor;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 import edu.uci.ics.hyracks.storage.am.common.datagen.DataGenThread;
+import edu.uci.ics.hyracks.storage.am.common.exceptions.TreeIndexDuplicateKeyException;
+import edu.uci.ics.hyracks.storage.am.common.exceptions.TreeIndexNonExistentKeyException;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.impls.LSMBTree;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.impls.LSMBTree.LSMBTreeAccessor;
@@ -60,7 +60,7 @@
             case INSERT:
                 try {
                     accessor.insert(tuple);
-                } catch (BTreeDuplicateKeyException e) {
+                } catch (TreeIndexDuplicateKeyException e) {
                     // Ignore duplicate keys, since we get random tuples.
                 }
                 break;
@@ -74,7 +74,7 @@
                 deleteTuple.reset(deleteTb.getFieldEndOffsets(), deleteTb.getByteArray());
                 try {
                     accessor.delete(deleteTuple);
-                } catch (BTreeNonExistentKeyException e) {
+                } catch (TreeIndexNonExistentKeyException e) {
                     // Ignore non-existant keys, since we get random tuples.
                 }
                 break;
@@ -82,7 +82,7 @@
             case UPDATE:
                 try {
                     accessor.update(tuple);
-                } catch (BTreeNonExistentKeyException e) {
+                } catch (TreeIndexNonExistentKeyException e) {
                     // Ignore non-existant keys, since we get random tuples.
                 } catch (BTreeNotUpdateableException e) {
                     // Ignore not updateable exception due to numKeys == numFields.
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/perf/LSMTreeRunner.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/perf/LSMTreeRunner.java
index fc6642c..3591f78 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/perf/LSMTreeRunner.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/perf/LSMTreeRunner.java
@@ -17,7 +17,9 @@
 
 import java.io.File;
 import java.text.SimpleDateFormat;
+import java.util.ArrayList;
 import java.util.Date;
+import java.util.List;
 
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
@@ -88,10 +90,15 @@
         ioDeviceId = 0;
         IFileMapProvider fmp = TestStorageManagerComponentHolder.getFileMapProvider(ctx);
 
-        IVirtualBufferCache virtualBufferCache = new VirtualBufferCache(new HeapBufferAllocator(), inMemPageSize,
-                inMemNumPages);
+        List<IVirtualBufferCache> virtualBufferCaches = new ArrayList<IVirtualBufferCache>();
+        for (int i = 0; i < 2; i++) {
+            IVirtualBufferCache virtualBufferCache = new VirtualBufferCache(new HeapBufferAllocator(), inMemPageSize,
+                    inMemNumPages);
+            virtualBufferCaches.add(virtualBufferCache);
+        }
+
         this.ioScheduler = SynchronousScheduler.INSTANCE;
-        lsmtree = LSMBTreeUtils.createLSMTree(virtualBufferCache, file, bufferCache, fmp, typeTraits, cmpFactories,
+        lsmtree = LSMBTreeUtils.createLSMTree(virtualBufferCaches, file, bufferCache, fmp, typeTraits, cmpFactories,
                 bloomFilterKeyFields, bloomFilterFalsePositiveRate, NoMergePolicy.INSTANCE,
                 new ThreadCountingTracker(), ioScheduler, NoOpIOOperationCallback.INSTANCE);
     }
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestContext.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestContext.java
index ab78ee6..6f7c23a 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestContext.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestContext.java
@@ -16,6 +16,7 @@
 package edu.uci.ics.hyracks.storage.am.lsm.btree.util;
 
 import java.util.Collection;
+import java.util.List;
 
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
@@ -27,7 +28,7 @@
 import edu.uci.ics.hyracks.storage.am.common.CheckTuple;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.impls.LSMBTree;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
@@ -62,20 +63,20 @@
         upsertCheckTuple(checkTuple, checkTuples);
     }
 
-    public static LSMBTreeTestContext create(IVirtualBufferCache virtualBufferCache, FileReference file,
+    public static LSMBTreeTestContext create(List<IVirtualBufferCache> virtualBufferCaches, FileReference file,
             IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ISerializerDeserializer[] fieldSerdes,
             int numKeyFields, double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy,
-            ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider) throws Exception {
+            ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallback ioOpCallback)
+            throws Exception {
         ITypeTraits[] typeTraits = SerdeUtils.serdesToTypeTraits(fieldSerdes);
         IBinaryComparatorFactory[] cmpFactories = SerdeUtils.serdesToComparatorFactories(fieldSerdes, numKeyFields);
         int[] bloomFilterKeyFields = new int[numKeyFields];
         for (int i = 0; i < numKeyFields; ++i) {
             bloomFilterKeyFields[i] = i;
         }
-        LSMBTree lsmTree = LSMBTreeUtils.createLSMTree(virtualBufferCache, file, diskBufferCache, diskFileMapProvider,
+        LSMBTree lsmTree = LSMBTreeUtils.createLSMTree(virtualBufferCaches, file, diskBufferCache, diskFileMapProvider,
                 typeTraits, cmpFactories, bloomFilterKeyFields, bloomFilterFalsePositiveRate, mergePolicy, opTracker,
-                ioScheduler, ioOpCallbackProvider);
+                ioScheduler, ioOpCallback);
         LSMBTreeTestContext testCtx = new LSMBTreeTestContext(fieldSerdes, lsmTree);
         return testCtx;
     }
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestHarness.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestHarness.java
index e643cf9..b88da7b 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestHarness.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestHarness.java
@@ -18,7 +18,9 @@
 import java.io.File;
 import java.io.FilenameFilter;
 import java.text.SimpleDateFormat;
+import java.util.ArrayList;
 import java.util.Date;
+import java.util.List;
 import java.util.Random;
 import java.util.logging.Logger;
 
@@ -30,7 +32,7 @@
 import edu.uci.ics.hyracks.control.nc.io.IOManager;
 import edu.uci.ics.hyracks.storage.am.btree.frames.BTreeLeafFrameType;
 import edu.uci.ics.hyracks.storage.am.config.AccessMethodTestsConfig;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
@@ -60,17 +62,18 @@
     protected final int memNumPages;
     protected final int hyracksFrameSize;
     protected final double bloomFilterFalsePositiveRate;
+    protected final int numMutableComponents;
 
     protected IOManager ioManager;
     protected int ioDeviceId;
     protected IBufferCache diskBufferCache;
     protected IFileMapProvider diskFileMapProvider;
-    protected IVirtualBufferCache virtualBufferCache;
+    protected List<IVirtualBufferCache> virtualBufferCaches;
     protected IHyracksTaskContext ctx;
     protected ILSMIOOperationScheduler ioScheduler;
     protected ILSMMergePolicy mergePolicy;
     protected ILSMOperationTracker opTracker;
-    protected ILSMIOOperationCallbackProvider ioOpCallbackProvider;
+    protected ILSMIOOperationCallback ioOpCallback;
 
     protected final Random rnd = new Random();
     protected final static SimpleDateFormat simpleDateFormat = new SimpleDateFormat("ddMMyy-hhmmssSS");
@@ -89,21 +92,8 @@
         this.ioScheduler = SynchronousScheduler.INSTANCE;
         this.mergePolicy = NoMergePolicy.INSTANCE;
         this.opTracker = new ThreadCountingTracker();
-        this.ioOpCallbackProvider = NoOpIOOperationCallback.INSTANCE;
-    }
-
-    public LSMBTreeTestHarness(int diskPageSize, int diskNumPages, int diskMaxOpenFiles, int memPageSize,
-            int memNumPages, int hyracksFrameSize, double bloomFilterFalsePositiveRate) {
-        this.diskPageSize = diskPageSize;
-        this.diskNumPages = diskNumPages;
-        this.diskMaxOpenFiles = diskMaxOpenFiles;
-        this.memPageSize = memPageSize;
-        this.memNumPages = memNumPages;
-        this.hyracksFrameSize = hyracksFrameSize;
-        this.bloomFilterFalsePositiveRate = bloomFilterFalsePositiveRate;
-        this.ioScheduler = SynchronousScheduler.INSTANCE;
-        this.mergePolicy = NoMergePolicy.INSTANCE;
-        this.opTracker = new ThreadCountingTracker();
+        this.ioOpCallback = NoOpIOOperationCallback.INSTANCE;
+        this.numMutableComponents = AccessMethodTestsConfig.LSM_BTREE_NUM_MUTABLE_COMPONENTS;
     }
 
     public void setUp() throws HyracksException {
@@ -116,7 +106,12 @@
         TestStorageManagerComponentHolder.init(diskPageSize, diskNumPages, diskMaxOpenFiles);
         diskBufferCache = TestStorageManagerComponentHolder.getBufferCache(ctx);
         diskFileMapProvider = TestStorageManagerComponentHolder.getFileMapProvider(ctx);
-        virtualBufferCache = new VirtualBufferCache(new HeapBufferAllocator(), memPageSize, memNumPages);
+        virtualBufferCaches = new ArrayList<IVirtualBufferCache>();
+        for (int i = 0; i < numMutableComponents; i++) {
+            IVirtualBufferCache virtualBufferCache = new VirtualBufferCache(new HeapBufferAllocator(), memPageSize,
+                    memNumPages / numMutableComponents);
+            virtualBufferCaches.add(virtualBufferCache);
+        }
         rnd.setSeed(RANDOM_SEED);
     }
 
@@ -179,8 +174,8 @@
         return diskFileMapProvider;
     }
 
-    public IVirtualBufferCache getVirtualBufferCache() {
-        return virtualBufferCache;
+    public List<IVirtualBufferCache> getVirtualBufferCaches() {
+        return virtualBufferCaches;
     }
 
     public double getBoomFilterFalsePositiveRate() {
@@ -211,7 +206,7 @@
         return mergePolicy;
     }
 
-    public ILSMIOOperationCallbackProvider getIOOperationCallbackProvider() {
-        return ioOpCallbackProvider;
+    public ILSMIOOperationCallback getIOOperationCallback() {
+        return ioOpCallback;
     }
 }
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-common-test/pom.xml b/hyracks/hyracks-tests/hyracks-storage-am-lsm-common-test/pom.xml
index b180994..7a4dc6f 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-common-test/pom.xml
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-common-test/pom.xml
@@ -19,7 +19,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks-tests</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -39,14 +39,14 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-lsm-common</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-test-support</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/pom.xml b/hyracks/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/pom.xml
index 45a5837..ba3e606 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/pom.xml
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/pom.xml
@@ -19,7 +19,7 @@
 	<parent>
 		<artifactId>hyracks-tests</artifactId>
 		<groupId>edu.uci.ics.hyracks</groupId>
-		<version>0.2.7-SNAPSHOT</version>
+		<version>0.2.10-SNAPSHOT</version>
 		<relativePath>..</relativePath>
 	</parent>
 
@@ -40,21 +40,21 @@
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-storage-am-lsm-invertedindex</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-test-support</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>test</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-data-std</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>test</scope>
 		</dependency>
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/common/LSMInvertedIndexTestHarness.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/common/LSMInvertedIndexTestHarness.java
index 7276464..0907fc0 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/common/LSMInvertedIndexTestHarness.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/common/LSMInvertedIndexTestHarness.java
@@ -18,7 +18,9 @@
 import java.io.File;
 import java.io.FilenameFilter;
 import java.text.SimpleDateFormat;
+import java.util.ArrayList;
 import java.util.Date;
+import java.util.List;
 import java.util.Random;
 
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
@@ -27,14 +29,12 @@
 import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.api.io.IODeviceHandle;
 import edu.uci.ics.hyracks.control.nc.io.IOManager;
-import edu.uci.ics.hyracks.storage.am.common.api.IVirtualFreePageManager;
 import edu.uci.ics.hyracks.storage.am.config.AccessMethodTestsConfig;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.VirtualFreePageManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.MultitenantVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoOpIOOperationCallback;
@@ -58,18 +58,18 @@
     protected final int memNumPages;
     protected final int hyracksFrameSize;
     protected final double bloomFilterFalsePositiveRate;
+    protected final int numMutableComponents;
 
     protected IOManager ioManager;
     protected int ioDeviceId;
     protected IBufferCache diskBufferCache;
     protected IFileMapProvider diskFileMapProvider;
-    protected IVirtualBufferCache virtualBufferCache;
-    protected IVirtualFreePageManager virtualFreePageManager;
+    protected List<IVirtualBufferCache> virtualBufferCaches;
     protected IHyracksTaskContext ctx;
     protected ILSMIOOperationScheduler ioScheduler;
     protected ILSMMergePolicy mergePolicy;
     protected ILSMOperationTracker opTracker;
-    protected ILSMIOOperationCallbackProvider ioOpCallbackProvider;
+    protected ILSMIOOperationCallback ioOpCallback;
 
     protected final Random rnd = new Random();
     protected final static SimpleDateFormat simpleDateFormat = new SimpleDateFormat("ddMMyy-hhmmssSS");
@@ -90,21 +90,8 @@
         this.ioScheduler = SynchronousScheduler.INSTANCE;
         this.mergePolicy = NoMergePolicy.INSTANCE;
         this.opTracker = new ThreadCountingTracker();
-        this.ioOpCallbackProvider = NoOpIOOperationCallback.INSTANCE;
-    }
-
-    public LSMInvertedIndexTestHarness(int diskPageSize, int diskNumPages, int diskMaxOpenFiles, int memPageSize,
-            int memNumPages, int hyracksFrameSize, double bloomFilterFalsePositiveRate) {
-        this.diskPageSize = diskPageSize;
-        this.diskNumPages = diskNumPages;
-        this.diskMaxOpenFiles = diskMaxOpenFiles;
-        this.memPageSize = memPageSize;
-        this.memNumPages = memNumPages;
-        this.hyracksFrameSize = hyracksFrameSize;
-        this.bloomFilterFalsePositiveRate = bloomFilterFalsePositiveRate;
-        this.ioScheduler = SynchronousScheduler.INSTANCE;
-        this.mergePolicy = NoMergePolicy.INSTANCE;
-        this.opTracker = new ThreadCountingTracker();
+        this.ioOpCallback = NoOpIOOperationCallback.INSTANCE;
+        this.numMutableComponents = AccessMethodTestsConfig.LSM_INVINDEX_NUM_MUTABLE_COMPONENTS;
     }
 
     public void setUp() throws HyracksException {
@@ -116,10 +103,13 @@
         TestStorageManagerComponentHolder.init(diskPageSize, diskNumPages, diskMaxOpenFiles);
         diskBufferCache = TestStorageManagerComponentHolder.getBufferCache(ctx);
         diskFileMapProvider = TestStorageManagerComponentHolder.getFileMapProvider(ctx);
-        virtualBufferCache = new MultitenantVirtualBufferCache(new VirtualBufferCache(new HeapBufferAllocator(),
-                memPageSize, memNumPages));
-        virtualBufferCache.open();
-        virtualFreePageManager = new VirtualFreePageManager(memNumPages);
+        virtualBufferCaches = new ArrayList<IVirtualBufferCache>();
+        for (int i = 0; i < numMutableComponents; i++) {
+            IVirtualBufferCache virtualBufferCache = new MultitenantVirtualBufferCache(new VirtualBufferCache(
+                    new HeapBufferAllocator(), memPageSize, memNumPages / numMutableComponents));
+            virtualBufferCaches.add(virtualBufferCache);
+            virtualBufferCache.open();
+        }
         rnd.setSeed(RANDOM_SEED);
         invIndexFileRef = ioManager.getIODevices().get(0).createFileReference(onDiskDir + invIndexFileName);
     }
@@ -141,7 +131,9 @@
             }
         }
         dir.delete();
-        virtualBufferCache.close();
+        for (int i = 0; i < numMutableComponents; i++) {
+            virtualBufferCaches.get(i).close();
+        }
     }
 
     public FileReference getInvListsFileRef() {
@@ -188,18 +180,14 @@
         return diskFileMapProvider;
     }
 
-    public IVirtualBufferCache getVirtualBufferCache() {
-        return virtualBufferCache;
+    public List<IVirtualBufferCache> getVirtualBufferCaches() {
+        return virtualBufferCaches;
     }
 
     public double getBoomFilterFalsePositiveRate() {
         return bloomFilterFalsePositiveRate;
     }
 
-    public IVirtualFreePageManager getVirtualFreePageManager() {
-        return virtualFreePageManager;
-    }
-
     public IHyracksTaskContext getHyracksTastContext() {
         return ctx;
     }
@@ -224,7 +212,7 @@
         return mergePolicy;
     }
 
-    public ILSMIOOperationCallbackProvider getIOOperationCallbackProvider() {
-        return ioOpCallbackProvider;
+    public ILSMIOOperationCallback getIOOperationCallback() {
+        return ioOpCallback;
     }
 }
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/LSMInvertedIndexTestContext.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/LSMInvertedIndexTestContext.java
index 05dc1b5..059df73 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/LSMInvertedIndexTestContext.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/LSMInvertedIndexTestContext.java
@@ -36,6 +36,7 @@
 import edu.uci.ics.hyracks.storage.am.common.CheckTuple;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.VirtualFreePageManager;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.common.LSMInvertedIndexTestHarness;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.exceptions.InvertedIndexException;
@@ -118,18 +119,20 @@
         }
         // Create index and test context.        
         IInvertedIndex invIndex;
+        assert harness.getVirtualBufferCaches().size() > 0;
         switch (invIndexType) {
             case INMEMORY: {
-                invIndex = InvertedIndexUtils.createInMemoryBTreeInvertedindex(harness.getVirtualBufferCache(),
-                        harness.getVirtualFreePageManager(), invListTypeTraits, invListCmpFactories, tokenTypeTraits,
-                        tokenCmpFactories, tokenizerFactory, new FileReference(new File(harness.getOnDiskDir())));
+                invIndex = InvertedIndexUtils.createInMemoryBTreeInvertedindex(harness.getVirtualBufferCaches().get(0),
+                        new VirtualFreePageManager(harness.getVirtualBufferCaches().get(0).getNumPages()),
+                        invListTypeTraits, invListCmpFactories, tokenTypeTraits, tokenCmpFactories, tokenizerFactory,
+                        new FileReference(new File(harness.getOnDiskDir())));
                 break;
             }
             case PARTITIONED_INMEMORY: {
                 invIndex = InvertedIndexUtils.createPartitionedInMemoryBTreeInvertedindex(harness
-                        .getVirtualBufferCache(), harness.getVirtualFreePageManager(), invListTypeTraits,
-                        invListCmpFactories, tokenTypeTraits, tokenCmpFactories, tokenizerFactory, new FileReference(
-                                new File(harness.getOnDiskDir())));
+                        .getVirtualBufferCaches().get(0), new VirtualFreePageManager(harness.getVirtualBufferCaches()
+                        .get(0).getNumPages()), invListTypeTraits, invListCmpFactories, tokenTypeTraits,
+                        tokenCmpFactories, tokenizerFactory, new FileReference(new File(harness.getOnDiskDir())));
                 break;
             }
             case ONDISK: {
@@ -145,21 +148,19 @@
                 break;
             }
             case LSM: {
-                invIndex = InvertedIndexUtils.createLSMInvertedIndex(harness.getVirtualBufferCache(),
+                invIndex = InvertedIndexUtils.createLSMInvertedIndex(harness.getVirtualBufferCaches(),
                         harness.getDiskFileMapProvider(), invListTypeTraits, invListCmpFactories, tokenTypeTraits,
                         tokenCmpFactories, tokenizerFactory, harness.getDiskBufferCache(), harness.getOnDiskDir(),
                         harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
-                        harness.getOperationTracker(), harness.getIOScheduler(),
-                        harness.getIOOperationCallbackProvider());
+                        harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallback());
                 break;
             }
             case PARTITIONED_LSM: {
-                invIndex = InvertedIndexUtils.createPartitionedLSMInvertedIndex(harness.getVirtualBufferCache(),
+                invIndex = InvertedIndexUtils.createPartitionedLSMInvertedIndex(harness.getVirtualBufferCaches(),
                         harness.getDiskFileMapProvider(), invListTypeTraits, invListCmpFactories, tokenTypeTraits,
                         tokenCmpFactories, tokenizerFactory, harness.getDiskBufferCache(), harness.getOnDiskDir(),
                         harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
-                        harness.getOperationTracker(), harness.getIOScheduler(),
-                        harness.getIOOperationCallbackProvider());
+                        harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallback());
                 break;
             }
             default: {
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/pom.xml b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/pom.xml
index 14863e5..3d4fece 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/pom.xml
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/pom.xml
@@ -19,7 +19,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks-tests</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -39,14 +39,14 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-lsm-rtree</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-test-support</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeBulkLoadTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeBulkLoadTest.java
index 3fcb4e5..dadd08c 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeBulkLoadTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeBulkLoadTest.java
@@ -54,10 +54,10 @@
     protected AbstractRTreeTestContext createTestContext(ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeys, RTreePolicyType rtreePolicyType)
             throws Exception {
-        return LSMRTreeTestContext.create(harness.getVirtualBufferCache(), harness.getFileReference(),
+        return LSMRTreeTestContext.create(harness.getVirtualBufferCaches(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories,
                 numKeys, rtreePolicyType, harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
-                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallbackProvider());
+                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallback());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeDeleteTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeDeleteTest.java
index 467916e..0b92cd3 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeDeleteTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeDeleteTest.java
@@ -54,10 +54,10 @@
     protected AbstractRTreeTestContext createTestContext(ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeys, RTreePolicyType rtreePolicyType)
             throws Exception {
-        return LSMRTreeTestContext.create(harness.getVirtualBufferCache(), harness.getFileReference(),
+        return LSMRTreeTestContext.create(harness.getVirtualBufferCaches(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories,
                 numKeys, rtreePolicyType, harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
-                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallbackProvider());
+                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallback());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeExamplesTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeExamplesTest.java
index a35170c..b04ae16 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeExamplesTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeExamplesTest.java
@@ -37,11 +37,11 @@
     protected ITreeIndex createTreeIndex(ITypeTraits[] typeTraits, IBinaryComparatorFactory[] rtreeCmpFactories,
             IBinaryComparatorFactory[] btreeCmpFactories, IPrimitiveValueProviderFactory[] valueProviderFactories,
             RTreePolicyType rtreePolicyType) throws TreeIndexException {
-        return LSMRTreeUtils.createLSMTree(harness.getVirtualBufferCache(), harness.getFileReference(),
+        return LSMRTreeUtils.createLSMTree(harness.getVirtualBufferCaches(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), typeTraits, rtreeCmpFactories,
                 btreeCmpFactories, valueProviderFactories, rtreePolicyType, harness.getBoomFilterFalsePositiveRate(),
                 harness.getMergePolicy(), harness.getOperationTracker(), harness.getIOScheduler(),
-                harness.getIOOperationCallbackProvider(),
+                harness.getIOOperationCallback(),
                 LSMRTreeUtils.proposeBestLinearizer(typeTraits, rtreeCmpFactories.length));
     }
 
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeInsertTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeInsertTest.java
index 44da0c0..35c6a6b 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeInsertTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeInsertTest.java
@@ -54,10 +54,10 @@
     protected AbstractRTreeTestContext createTestContext(ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeys, RTreePolicyType rtreePolicyType)
             throws Exception {
-        return LSMRTreeTestContext.create(harness.getVirtualBufferCache(), harness.getFileReference(),
+        return LSMRTreeTestContext.create(harness.getVirtualBufferCaches(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories,
                 numKeys, rtreePolicyType, harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
-                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallbackProvider());
+                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallback());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeLifecycleTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeLifecycleTest.java
index b97bebb..6ef2e94 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeLifecycleTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeLifecycleTest.java
@@ -63,10 +63,10 @@
     @Override
     public void setup() throws Exception {
         harness.setUp();
-        testCtx = LSMRTreeTestContext.create(harness.getVirtualBufferCache(), harness.getFileReference(),
+        testCtx = LSMRTreeTestContext.create(harness.getVirtualBufferCaches(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories,
                 numKeys, RTreePolicyType.RTREE, harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
-                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallbackProvider());
+                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallback());
         index = testCtx.getIndex();
     }
 
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeMergeTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeMergeTest.java
index b13ce4d..94528e7 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeMergeTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeMergeTest.java
@@ -53,10 +53,10 @@
     protected AbstractRTreeTestContext createTestContext(ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeys, RTreePolicyType rtreePolicyType)
             throws Exception {
-        return LSMRTreeTestContext.create(harness.getVirtualBufferCache(), harness.getFileReference(),
+        return LSMRTreeTestContext.create(harness.getVirtualBufferCaches(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories,
                 numKeys, rtreePolicyType, harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
-                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallbackProvider());
+                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallback());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesBulkLoadTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesBulkLoadTest.java
index 2baf485..22a6eb8 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesBulkLoadTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesBulkLoadTest.java
@@ -54,10 +54,10 @@
     protected AbstractRTreeTestContext createTestContext(ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeys, RTreePolicyType rtreePolicyType)
             throws Exception {
-        return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getVirtualBufferCache(),
+        return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getVirtualBufferCaches(),
                 harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
                 fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType, harness.getMergePolicy(),
-                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallbackProvider());
+                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallback());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesDeleteTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesDeleteTest.java
index 9c440cc..10aec7e 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesDeleteTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesDeleteTest.java
@@ -54,10 +54,10 @@
     protected AbstractRTreeTestContext createTestContext(ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeys, RTreePolicyType rtreePolicyType)
             throws Exception {
-        return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getVirtualBufferCache(),
+        return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getVirtualBufferCaches(),
                 harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
                 fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType, harness.getMergePolicy(),
-                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallbackProvider());
+                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallback());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesExamplesTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesExamplesTest.java
index 909d0cd..a51abef 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesExamplesTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesExamplesTest.java
@@ -37,11 +37,11 @@
     protected ITreeIndex createTreeIndex(ITypeTraits[] typeTraits, IBinaryComparatorFactory[] rtreeCmpFactories,
             IBinaryComparatorFactory[] btreeCmpFactories, IPrimitiveValueProviderFactory[] valueProviderFactories,
             RTreePolicyType rtreePolicyType) throws TreeIndexException {
-        return LSMRTreeUtils.createLSMTreeWithAntiMatterTuples(harness.getVirtualBufferCache(),
+        return LSMRTreeUtils.createLSMTreeWithAntiMatterTuples(harness.getVirtualBufferCaches(),
                 harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), typeTraits,
                 rtreeCmpFactories, btreeCmpFactories, valueProviderFactories, rtreePolicyType,
                 harness.getMergePolicy(), harness.getOperationTracker(), harness.getIOScheduler(),
-                harness.getIOOperationCallbackProvider(),
+                harness.getIOOperationCallback(),
                 LSMRTreeUtils.proposeBestLinearizer(typeTraits, rtreeCmpFactories.length));
     }
 
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesInsertTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesInsertTest.java
index 6b35192..e5b33cc 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesInsertTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesInsertTest.java
@@ -54,10 +54,10 @@
     protected AbstractRTreeTestContext createTestContext(ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeys, RTreePolicyType rtreePolicyType)
             throws Exception {
-        return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getVirtualBufferCache(),
+        return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getVirtualBufferCaches(),
                 harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
                 fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType, harness.getMergePolicy(),
-                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallbackProvider());
+                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallback());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesLifecycleTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesLifecycleTest.java
index 6dcbdf2..10ae5e1 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesLifecycleTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesLifecycleTest.java
@@ -63,10 +63,10 @@
     @Override
     public void setup() throws Exception {
         harness.setUp();
-        testCtx = LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getVirtualBufferCache(),
+        testCtx = LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getVirtualBufferCaches(),
                 harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
                 fieldSerdes, valueProviderFactories, numKeys, RTreePolicyType.RTREE, harness.getMergePolicy(),
-                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallbackProvider());
+                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallback());
         index = testCtx.getIndex();
     }
 
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesMergeTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesMergeTest.java
index dc81fc3..21d3759 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesMergeTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesMergeTest.java
@@ -53,10 +53,10 @@
     protected AbstractRTreeTestContext createTestContext(ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeys, RTreePolicyType rtreePolicyType)
             throws Exception {
-        return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getVirtualBufferCache(),
+        return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getVirtualBufferCaches(),
                 harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
                 fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType, harness.getMergePolicy(),
-                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallbackProvider());
+                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallback());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeMultiThreadTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeMultiThreadTest.java
index 850d540..077bd45 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeMultiThreadTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeMultiThreadTest.java
@@ -57,11 +57,11 @@
     protected ITreeIndex createTreeIndex(ITypeTraits[] typeTraits, IBinaryComparatorFactory[] rtreeCmpFactories,
             IBinaryComparatorFactory[] btreeCmpFactories, IPrimitiveValueProviderFactory[] valueProviderFactories,
             RTreePolicyType rtreePolicyType) throws TreeIndexException {
-        return LSMRTreeUtils.createLSMTree(harness.getVirtualBufferCache(), harness.getFileReference(),
+        return LSMRTreeUtils.createLSMTree(harness.getVirtualBufferCaches(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), typeTraits, rtreeCmpFactories,
                 btreeCmpFactories, valueProviderFactories, rtreePolicyType, harness.getBoomFilterFalsePositiveRate(),
                 harness.getMergePolicy(), harness.getOperationTracker(), harness.getIOScheduler(),
-                harness.getIOOperationCallbackProvider(),
+                harness.getIOOperationCallback(),
                 LSMRTreeUtils.proposeBestLinearizer(typeTraits, rtreeCmpFactories.length));
     }
 
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeWithAntiMatterTuplesMultiThreadTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeWithAntiMatterTuplesMultiThreadTest.java
index 4a6b462..ef871dd 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeWithAntiMatterTuplesMultiThreadTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeWithAntiMatterTuplesMultiThreadTest.java
@@ -57,11 +57,11 @@
     protected ITreeIndex createTreeIndex(ITypeTraits[] typeTraits, IBinaryComparatorFactory[] rtreeCmpFactories,
             IBinaryComparatorFactory[] btreeCmpFactories, IPrimitiveValueProviderFactory[] valueProviderFactories,
             RTreePolicyType rtreePolicyType) throws TreeIndexException {
-        return LSMRTreeUtils.createLSMTreeWithAntiMatterTuples(harness.getVirtualBufferCache(),
+        return LSMRTreeUtils.createLSMTreeWithAntiMatterTuples(harness.getVirtualBufferCaches(),
                 harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), typeTraits,
                 rtreeCmpFactories, btreeCmpFactories, valueProviderFactories, rtreePolicyType,
                 harness.getMergePolicy(), harness.getOperationTracker(), harness.getIOScheduler(),
-                harness.getIOOperationCallbackProvider(),
+                harness.getIOOperationCallback(),
                 LSMRTreeUtils.proposeBestLinearizer(typeTraits, rtreeCmpFactories.length));
 
     }
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestContext.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestContext.java
index 8c59e31..42e793b 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestContext.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestContext.java
@@ -16,6 +16,7 @@
 package edu.uci.ics.hyracks.storage.am.lsm.rtree.util;
 
 import java.util.Collection;
+import java.util.List;
 
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
@@ -25,7 +26,7 @@
 import edu.uci.ics.hyracks.dataflow.common.util.SerdeUtils;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
@@ -66,20 +67,19 @@
         return lsmTree.getComparatorFactories();
     }
 
-    public static LSMRTreeTestContext create(IVirtualBufferCache virtualBufferCache, FileReference file,
+    public static LSMRTreeTestContext create(List<IVirtualBufferCache> virtualBufferCaches, FileReference file,
             IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeyFields, RTreePolicyType rtreePolicyType,
             double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider)
-            throws Exception {
+            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallback ioOpCallback) throws Exception {
         ITypeTraits[] typeTraits = SerdeUtils.serdesToTypeTraits(fieldSerdes);
         IBinaryComparatorFactory[] rtreeCmpFactories = SerdeUtils
                 .serdesToComparatorFactories(fieldSerdes, numKeyFields);
         IBinaryComparatorFactory[] btreeCmpFactories = SerdeUtils.serdesToComparatorFactories(fieldSerdes,
                 fieldSerdes.length);
-        LSMRTree lsmTree = LSMRTreeUtils.createLSMTree(virtualBufferCache, file, diskBufferCache, diskFileMapProvider,
+        LSMRTree lsmTree = LSMRTreeUtils.createLSMTree(virtualBufferCaches, file, diskBufferCache, diskFileMapProvider,
                 typeTraits, rtreeCmpFactories, btreeCmpFactories, valueProviderFactories, rtreePolicyType,
-                bloomFilterFalsePositiveRate, mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider,
+                bloomFilterFalsePositiveRate, mergePolicy, opTracker, ioScheduler, ioOpCallback,
                 LSMRTreeUtils.proposeBestLinearizer(typeTraits, rtreeCmpFactories.length));
         LSMRTreeTestContext testCtx = new LSMRTreeTestContext(fieldSerdes, lsmTree);
         return testCtx;
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestHarness.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestHarness.java
index 118b1bc..66e79a2 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestHarness.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestHarness.java
@@ -18,7 +18,9 @@
 import java.io.File;
 import java.io.FilenameFilter;
 import java.text.SimpleDateFormat;
+import java.util.ArrayList;
 import java.util.Date;
+import java.util.List;
 import java.util.Random;
 import java.util.logging.Logger;
 
@@ -29,7 +31,7 @@
 import edu.uci.ics.hyracks.api.io.IODeviceHandle;
 import edu.uci.ics.hyracks.control.nc.io.IOManager;
 import edu.uci.ics.hyracks.storage.am.config.AccessMethodTestsConfig;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
@@ -57,15 +59,16 @@
     protected final int memNumPages;
     protected final int hyracksFrameSize;
     protected final double bloomFilterFalsePositiveRate;
+    protected final int numMutableComponents;
 
     protected IOManager ioManager;
     protected int ioDeviceId;
     protected IBufferCache diskBufferCache;
     protected IFileMapProvider diskFileMapProvider;
-    protected IVirtualBufferCache virtualBufferCache;
+    protected List<IVirtualBufferCache> virtualBufferCaches;
     protected IHyracksTaskContext ctx;
     protected ILSMIOOperationScheduler ioScheduler;
-    protected ILSMIOOperationCallbackProvider ioOpCallbackProvider;
+    protected ILSMIOOperationCallback ioOpCallback;
     protected ILSMMergePolicy mergePolicy;
     protected ILSMOperationTracker opTracker;
 
@@ -86,21 +89,8 @@
         this.ioScheduler = SynchronousScheduler.INSTANCE;
         this.mergePolicy = NoMergePolicy.INSTANCE;
         this.opTracker = new ThreadCountingTracker();
-        this.ioOpCallbackProvider = NoOpIOOperationCallback.INSTANCE;
-    }
-
-    public LSMRTreeTestHarness(int diskPageSize, int diskNumPages, int diskMaxOpenFiles, int memPageSize,
-            int memNumPages, int hyracksFrameSize, double bloomFilterFalsePositiveRate) {
-        this.diskPageSize = diskPageSize;
-        this.diskNumPages = diskNumPages;
-        this.diskMaxOpenFiles = diskMaxOpenFiles;
-        this.memPageSize = memPageSize;
-        this.memNumPages = memNumPages;
-        this.bloomFilterFalsePositiveRate = bloomFilterFalsePositiveRate;
-        this.hyracksFrameSize = hyracksFrameSize;
-        this.ioScheduler = SynchronousScheduler.INSTANCE;
-        this.mergePolicy = NoMergePolicy.INSTANCE;
-        this.opTracker = new ThreadCountingTracker();
+        this.ioOpCallback = NoOpIOOperationCallback.INSTANCE;
+        this.numMutableComponents = AccessMethodTestsConfig.LSM_RTREE_NUM_MUTABLE_COMPONENTS;
     }
 
     public void setUp() throws HyracksException {
@@ -113,7 +103,12 @@
         TestStorageManagerComponentHolder.init(diskPageSize, diskNumPages, diskMaxOpenFiles);
         diskBufferCache = TestStorageManagerComponentHolder.getBufferCache(ctx);
         diskFileMapProvider = TestStorageManagerComponentHolder.getFileMapProvider(ctx);
-        virtualBufferCache = new VirtualBufferCache(new HeapBufferAllocator(), memPageSize, memNumPages);
+        virtualBufferCaches = new ArrayList<IVirtualBufferCache>();
+        for (int i = 0; i < numMutableComponents; i++) {
+            IVirtualBufferCache virtualBufferCache = new VirtualBufferCache(new HeapBufferAllocator(), memPageSize,
+                    memNumPages / numMutableComponents);
+            virtualBufferCaches.add(virtualBufferCache);
+        }
         rnd.setSeed(RANDOM_SEED);
     }
 
@@ -175,8 +170,8 @@
         return diskFileMapProvider;
     }
 
-    public IVirtualBufferCache getVirtualBufferCache() {
-        return virtualBufferCache;
+    public List<IVirtualBufferCache> getVirtualBufferCaches() {
+        return virtualBufferCaches;
     }
 
     public double getBoomFilterFalsePositiveRate() {
@@ -211,7 +206,7 @@
         return mergePolicy;
     }
 
-    public ILSMIOOperationCallbackProvider getIOOperationCallbackProvider() {
-        return ioOpCallbackProvider;
+    public ILSMIOOperationCallback getIOOperationCallback() {
+        return ioOpCallback;
     }
 }
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeWithAntiMatterTuplesTestContext.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeWithAntiMatterTuplesTestContext.java
index 95716f6..6a0a6bb 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeWithAntiMatterTuplesTestContext.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeWithAntiMatterTuplesTestContext.java
@@ -16,6 +16,7 @@
 package edu.uci.ics.hyracks.storage.am.lsm.rtree.util;
 
 import java.util.Collection;
+import java.util.List;
 
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
@@ -25,7 +26,7 @@
 import edu.uci.ics.hyracks.dataflow.common.util.SerdeUtils;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
@@ -67,20 +68,20 @@
         return lsmTree.getComparatorFactories();
     }
 
-    public static LSMRTreeWithAntiMatterTuplesTestContext create(IVirtualBufferCache virtualBufferCache,
+    public static LSMRTreeWithAntiMatterTuplesTestContext create(List<IVirtualBufferCache> virtualBufferCaches,
             FileReference file, IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider,
             ISerializerDeserializer[] fieldSerdes, IPrimitiveValueProviderFactory[] valueProviderFactories,
             int numKeyFields, RTreePolicyType rtreePolicyType, ILSMMergePolicy mergePolicy,
-            ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider) throws Exception {
+            ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallback ioOpCallback)
+            throws Exception {
         ITypeTraits[] typeTraits = SerdeUtils.serdesToTypeTraits(fieldSerdes);
         IBinaryComparatorFactory[] rtreeCmpFactories = SerdeUtils
                 .serdesToComparatorFactories(fieldSerdes, numKeyFields);
         IBinaryComparatorFactory[] btreeCmpFactories = SerdeUtils.serdesToComparatorFactories(fieldSerdes,
                 fieldSerdes.length);
-        LSMRTreeWithAntiMatterTuples lsmTree = LSMRTreeUtils.createLSMTreeWithAntiMatterTuples(virtualBufferCache,
+        LSMRTreeWithAntiMatterTuples lsmTree = LSMRTreeUtils.createLSMTreeWithAntiMatterTuples(virtualBufferCaches,
                 file, diskBufferCache, diskFileMapProvider, typeTraits, rtreeCmpFactories, btreeCmpFactories,
-                valueProviderFactories, rtreePolicyType, mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider,
+                valueProviderFactories, rtreePolicyType, mergePolicy, opTracker, ioScheduler, ioOpCallback,
                 LSMRTreeUtils.proposeBestLinearizer(typeTraits, rtreeCmpFactories.length));
         LSMRTreeWithAntiMatterTuplesTestContext testCtx = new LSMRTreeWithAntiMatterTuplesTestContext(fieldSerdes,
                 lsmTree);
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-rtree-test/pom.xml b/hyracks/hyracks-tests/hyracks-storage-am-rtree-test/pom.xml
index 8c5178e..547a3a4 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-rtree-test/pom.xml
+++ b/hyracks/hyracks-tests/hyracks-storage-am-rtree-test/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks-tests</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -48,14 +48,14 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-rtree</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-test-support</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>test</scope>
   	</dependency>
diff --git a/hyracks/hyracks-tests/hyracks-storage-common-test/pom.xml b/hyracks/hyracks-tests/hyracks-storage-common-test/pom.xml
index 0930280..d9fdc26 100644
--- a/hyracks/hyracks-tests/hyracks-storage-common-test/pom.xml
+++ b/hyracks/hyracks-tests/hyracks-storage-common-test/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks-tests</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -48,13 +48,13 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-common</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<scope>compile</scope>
   	</dependency>
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-test-support</artifactId>
-  		<version>0.2.7-SNAPSHOT</version>
+  		<version>0.2.10-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>
diff --git a/hyracks/hyracks-tests/pom.xml b/hyracks/hyracks-tests/pom.xml
index 2990e53..441b76c 100644
--- a/hyracks/hyracks-tests/pom.xml
+++ b/hyracks/hyracks-tests/pom.xml
@@ -21,7 +21,7 @@
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.2.7-SNAPSHOT</version>
+    <version>0.2.10-SNAPSHOT</version>
   </parent>
 
   <modules>
diff --git a/hyracks/pom.xml b/hyracks/pom.xml
index 6282fdd..a4a54f2 100644
--- a/hyracks/pom.xml
+++ b/hyracks/pom.xml
@@ -17,7 +17,7 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>edu.uci.ics.hyracks</groupId>
   <artifactId>hyracks</artifactId>
-  <version>0.2.7-SNAPSHOT</version>
+  <version>0.2.10-SNAPSHOT</version>
   <packaging>pom</packaging>
   <name>hyracks</name>
 
diff --git a/pom.xml b/pom.xml
index 3428836..a851758 100644
--- a/pom.xml
+++ b/pom.xml
@@ -17,7 +17,7 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>edu.uci.ics.hyracks</groupId>
   <artifactId>fullstack</artifactId>
-  <version>0.2.7-SNAPSHOT</version>
+  <version>0.2.10-SNAPSHOT</version>
   <packaging>pom</packaging>
   <name>hyracks-ecosystem-full-stack</name>
 
diff --git a/pregelix/build.sh b/pregelix/build.sh
new file mode 100644
index 0000000..e213181
--- /dev/null
+++ b/pregelix/build.sh
@@ -0,0 +1,12 @@
+rm -rf dist
+mkdir dist
+
+hadoop_versions=(0.20.2 0.23.1 0.23.6 1.0.4 cdh-4.1 cdh-4.2)
+cd ../
+for v in ${hadoop_versions[@]}
+do
+   #echo mvn clean package -DskipTests=true -Dhadoop=${v}
+   mvn clean package -DskipTests=true -Dhadoop=${v}
+   #echo mv pregelix/pregelix-dist/target/pregelix-dist-*-binary-assembly.zip pregelix/dist/pregelix-dist-binary-assembley-hdfs-${v}.zip
+   mv pregelix/pregelix-dist/target/pregelix-dist-*-binary-assembly.zip pregelix/dist/pregelix-dist-binary-assembley-hdfs-${v}.zip
+done
diff --git a/pregelix/pom.xml b/pregelix/pom.xml
index c0c3822..d748d1f 100644
--- a/pregelix/pom.xml
+++ b/pregelix/pom.xml
@@ -12,17 +12,16 @@
  ! WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  ! See the License for the specific language governing permissions and
  ! limitations under the License.
- !-->
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+ !--><project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
   <modelVersion>4.0.0</modelVersion>
   <groupId>edu.uci.ics.hyracks</groupId>
   <artifactId>pregelix</artifactId>
-  <version>0.2.7-SNAPSHOT</version>
+  <version>0.2.10-SNAPSHOT</version>
   <packaging>pom</packaging>
   <name>pregelix</name>
 
   <properties>
-    <jvm.extraargs />
+    <jvm.extraargs/>
   </properties>
 
   <profiles>
@@ -107,6 +106,7 @@
     <module>pregelix-runtime</module>
     <module>pregelix-core</module>
     <module>pregelix-example</module>
+    <module>pregelix-benchmark</module>
     <module>pregelix-dist</module>
   </modules>
 </project>
diff --git a/pregelix/pregelix-api/pom.xml b/pregelix/pregelix-api/pom.xml
index 305b50c..0152a15 100644
--- a/pregelix/pregelix-api/pom.xml
+++ b/pregelix/pregelix-api/pom.xml
@@ -21,7 +21,7 @@
 	<parent>
 		<groupId>edu.uci.ics.hyracks</groupId>
 		<artifactId>pregelix</artifactId>
-		<version>0.2.7-SNAPSHOT</version>
+		<version>0.2.10-SNAPSHOT</version>
 	</parent>
 
 	<properties>
@@ -82,7 +82,7 @@
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-dataflow-common</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
@@ -95,7 +95,7 @@
 		<dependency>
                         <groupId>edu.uci.ics.hyracks</groupId>
                         <artifactId>hyracks-hdfs-core</artifactId>
-                        <version>0.2.7-SNAPSHOT</version>
+                        <version>0.2.10-SNAPSHOT</version>
                         <type>jar</type>
                         <scope>compile</scope>
                 </dependency>
diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/GlobalAggregator.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/GlobalAggregator.java
index 08c7151..5ea6413 100644
--- a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/GlobalAggregator.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/GlobalAggregator.java
@@ -20,6 +20,7 @@
 import org.apache.hadoop.io.WritableComparable;
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.pregelix.api.io.WritableSizable;
 
 /**
  * This is the abstract class to implement for aggregating the state of all the vertices globally in the graph.
@@ -39,7 +40,7 @@
  */
 
 @SuppressWarnings("rawtypes")
-public abstract class GlobalAggregator<I extends WritableComparable, V extends Writable, E extends Writable, M extends Writable, P extends Writable, F extends Writable> {
+public abstract class GlobalAggregator<I extends WritableComparable, V extends Writable, E extends Writable, M extends WritableSizable, P extends Writable, F extends Writable> {
     /**
      * initialize aggregator
      */
diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/MessageCombiner.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/MessageCombiner.java
index f5daf99..fa03c0c 100644
--- a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/MessageCombiner.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/MessageCombiner.java
@@ -19,6 +19,7 @@
 import org.apache.hadoop.io.WritableComparable;
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.pregelix.api.io.WritableSizable;
 
 /**
  * This is the abstract class to implement for combining of messages that are sent to the same vertex.
@@ -36,7 +37,7 @@
  *        the type of the partially combined messages
  */
 @SuppressWarnings("rawtypes")
-public abstract class MessageCombiner<I extends WritableComparable, M extends Writable, P extends Writable> {
+public abstract class MessageCombiner<I extends WritableComparable, M extends WritableSizable, P extends Writable> {
 
     /**
      * initialize combiner
@@ -82,4 +83,36 @@
      * @return the final message List
      */
     public abstract MsgList<M> finishFinal();
+
+    /**
+     * init the combiner for all segmented bags for one key
+     * 
+     * @return the final message List
+     */
+    public void initAll(MsgList providedMsgList) {
+        init(providedMsgList);
+    }
+
+    /**
+     * finish final combiner for all segmented bags for one key
+     * 
+     * @return the final message List
+     */
+    public MsgList<M> finishFinalAll() {
+        return finishFinal();
+    }
+
+    /**
+     * @return the accumulated byte size
+     */
+    public int estimateAccumulatedStateByteSizePartial(I vertexIndex, M msg) throws HyracksDataException {
+        return 0;
+    }
+
+    /**
+     * @return the accumulated byte size
+     */
+    public int estimateAccumulatedStateByteSizeFinal(I vertexIndex, P partialAggregate) throws HyracksDataException {
+        return 0;
+    }
 }
diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/MsgList.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/MsgList.java
index 104f396..51b62e4 100644
--- a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/MsgList.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/MsgList.java
@@ -15,8 +15,11 @@
 
 package edu.uci.ics.pregelix.api.graph;
 
-import org.apache.hadoop.io.Writable;
+import java.io.DataInput;
+import java.io.DataOutput;
+import java.io.IOException;
 
+import edu.uci.ics.pregelix.api.io.WritableSizable;
 import edu.uci.ics.pregelix.api.util.ArrayListWritable;
 import edu.uci.ics.pregelix.api.util.BspUtils;
 
@@ -27,9 +30,11 @@
  * @param <M>
  *            message type
  */
-public class MsgList<M extends Writable> extends ArrayListWritable<M> {
+public class MsgList<M extends WritableSizable> extends ArrayListWritable<M> {
     /** Defining a layout version for a serializable class. */
     private static final long serialVersionUID = 1L;
+    private byte start = 1;
+    private byte end = 2;
 
     /**
      * Default constructor.s
@@ -43,4 +48,34 @@
     public void setClass() {
         setClass((Class<M>) BspUtils.getMessageValueClass(getConf()));
     }
+
+    @Override
+    public void write(DataOutput output) throws IOException {
+        output.writeByte(start | end);
+        super.write(output);
+    }
+
+    @Override
+    public void readFields(DataInput input) throws IOException {
+        byte startEnd = input.readByte();
+        this.start = (byte) (startEnd & 1);
+        this.end = (byte) (startEnd & 2);
+        super.readFields(input);
+    }
+
+    public final void setSegmentStart(boolean segStart) {
+        this.start = (byte) (segStart ? 1 : 0);
+    }
+
+    public final void setSegmentEnd(boolean segEnd) {
+        this.end = (byte) (segEnd ? 2 : 0);
+    }
+
+    public boolean segmentStart() {
+        return start == 1 ? true : false;
+    }
+
+    public boolean segmentEnd() {
+        return end == 2 ? true : false;
+    }
 }
diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/Vertex.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/Vertex.java
index 4175078..26cb8d0 100644
--- a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/Vertex.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/Vertex.java
@@ -24,15 +24,18 @@
 import java.util.List;
 import java.util.Map;
 
+import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.io.Writable;
 import org.apache.hadoop.io.WritableComparable;
+import org.apache.hadoop.io.WritableUtils;
 import org.apache.hadoop.mapreduce.TaskAttemptContext;
 
 import edu.uci.ics.hyracks.api.comm.IFrameWriter;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAppender;
+import edu.uci.ics.pregelix.api.io.WritableSizable;
 import edu.uci.ics.pregelix.api.util.BspUtils;
-import edu.uci.ics.pregelix.api.util.SerDeUtils;
+import edu.uci.ics.pregelix.api.util.JobStateUtils;
 
 /**
  * User applications should all inherit {@link Vertex}, and implement their own
@@ -48,7 +51,7 @@
  *            Message value type
  */
 @SuppressWarnings("rawtypes")
-public abstract class Vertex<I extends WritableComparable, V extends Writable, E extends Writable, M extends Writable>
+public abstract class Vertex<I extends WritableComparable, V extends Writable, E extends Writable, M extends WritableSizable>
         implements Writable {
     private static long superstep = 0;
     /** Class-wide number of vertices */
@@ -75,6 +78,8 @@
     private boolean hasMessage = false;
     /** created new vertex */
     private boolean createdNewLiveVertex = false;
+    /** terminate the partition */
+    private boolean terminatePartition = false;
 
     /**
      * use object pool for re-using objects
@@ -87,12 +92,23 @@
     private int usedValue = 0;
 
     /**
-     * The key method that users need to implement
+     * The key method that users need to implement to process
+     * incoming messages in each superstep.
+     * 1. In a superstep, this method can be called multiple times in a continuous manner for a single
+     * vertex, each of which is to process a batch of messages. (Note that
+     * this only happens for the case when the mssages for a single vertex
+     * exceed one frame.)
+     * 2. In each superstep, before any invocation of this method for a vertex,
+     * open() is called; after all the invocations of this method for the vertex,
+     * close is called.
+     * 3. In each partition, the vertex Java object is reused
+     * for all the vertice to be processed in the same partition. (The model
+     * is the same as the key-value objects in hadoop map tasks.)
      * 
      * @param msgIterator
      *            an iterator of incoming messages
      */
-    public abstract void compute(Iterator<M> msgIterator);
+    public abstract void compute(Iterator<M> msgIterator) throws Exception;
 
     /**
      * Add an edge for the vertex.
@@ -254,7 +270,7 @@
             delegate.setVertex(this);
         }
         destEdgeList.clear();
-        long edgeMapSize = SerDeUtils.readVLong(in);
+        long edgeMapSize = WritableUtils.readVLong(in);
         for (long i = 0; i < edgeMapSize; ++i) {
             Edge<I, E> edge = allocateEdge();
             edge.setConf(getContext().getConfiguration());
@@ -262,7 +278,7 @@
             addEdge(edge);
         }
         msgList.clear();
-        long msgListSize = SerDeUtils.readVLong(in);
+        long msgListSize = WritableUtils.readVLong(in);
         for (long i = 0; i < msgListSize; ++i) {
             M msg = allocateMessage();
             msg.readFields(in);
@@ -281,11 +297,11 @@
         if (vertexValue != null) {
             vertexValue.write(out);
         }
-        SerDeUtils.writeVLong(out, destEdgeList.size());
+        WritableUtils.writeVLong(out, destEdgeList.size());
         for (Edge<I, E> edge : destEdgeList) {
             edge.write(out);
         }
-        SerDeUtils.writeVLong(out, msgList.size());
+        WritableUtils.writeVLong(out, msgList.size());
         for (M msg : msgList) {
             msg.write(out);
         }
@@ -569,4 +585,61 @@
         Vertex.context = context;
     }
 
+    @Override
+    public int hashCode() {
+        return vertexId.hashCode();
+    }
+
+    @Override
+    public boolean equals(Object object) {
+        Vertex vertex = (Vertex) object;
+        return vertexId.equals(vertex.getVertexId());
+    }
+
+    /**
+     * called immediately before invocations of compute() on a vertex
+     * Users can override this method to initiate the state for a vertex
+     * before the compute() invocations
+     */
+    public void open() {
+
+    }
+
+    /**
+     * called immediately after all the invocations of compute() on a vertex
+     * Users can override this method to initiate the state for a vertex
+     * before the compute() invocations
+     */
+    public void close() {
+
+    }
+
+    /**
+     * Terminate the current partition where the current vertex stays in.
+     * This will immediately take effect and the upcoming vertice in the
+     * same partition cannot be processed.
+     */
+    protected final void terminatePartition() {
+        voteToHalt();
+        terminatePartition = true;
+    }
+
+    /**
+     * Terminate the Pregelix job.
+     * This will take effect only when the current iteration completed.
+     * 
+     * @throws Exception
+     */
+    protected void terminateJob() throws Exception {
+        Configuration conf = getContext().getConfiguration();
+        JobStateUtils.writeForceTerminationState(conf, BspUtils.getJobId(conf));
+    }
+
+    /***
+     * @return true if the partition is terminated; false otherwise
+     */
+    public boolean isPartitionTerminated() {
+        return terminatePartition;
+    }
+
 }
diff --git a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/Sizable.java
similarity index 64%
copy from hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
copy to pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/Sizable.java
index cde5022..568500b 100644
--- a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/Sizable.java
@@ -12,17 +12,12 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+package edu.uci.ics.pregelix.api.io;
 
-package edu.uci.ics.hyracks.storage.am.btree.exceptions;
+/**
+ * @author yingyib
+ */
+public interface Sizable {
 
-public class BTreeDuplicateKeyException extends BTreeException {
-    private static final long serialVersionUID = 1L;
-
-    public BTreeDuplicateKeyException(Exception e) {
-        super(e);
-    }
-
-    public BTreeDuplicateKeyException(String message) {
-        super(message);
-    }
+    public int sizeInBytes();
 }
diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/VertexInputFormat.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/VertexInputFormat.java
index c841b1a..73af190 100644
--- a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/VertexInputFormat.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/VertexInputFormat.java
@@ -40,7 +40,7 @@
  *            Message data
  */
 @SuppressWarnings("rawtypes")
-public abstract class VertexInputFormat<I extends WritableComparable, V extends Writable, E extends Writable, M extends Writable> {
+public abstract class VertexInputFormat<I extends WritableComparable, V extends Writable, E extends Writable, M extends WritableSizable> {
     /**
      * Logically split the vertices for a graph processing application.
      * Each {@link InputSplit} is then assigned to a worker for processing.
diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/VertexReader.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/VertexReader.java
index e6c62ba..ba8b561 100644
--- a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/VertexReader.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/VertexReader.java
@@ -39,7 +39,7 @@
  *            Message data
  */
 @SuppressWarnings("rawtypes")
-public interface VertexReader<I extends WritableComparable, V extends Writable, E extends Writable, M extends Writable> {
+public interface VertexReader<I extends WritableComparable, V extends Writable, E extends Writable, M extends WritableSizable> {
     /**
      * Use the input split and context t o setup reading the vertices.
      * Guaranteed to be called prior to any other function.
diff --git a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/WritableSizable.java
similarity index 64%
copy from hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
copy to pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/WritableSizable.java
index cde5022..ee13f76 100644
--- a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/WritableSizable.java
@@ -12,17 +12,13 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+package edu.uci.ics.pregelix.api.io;
 
-package edu.uci.ics.hyracks.storage.am.btree.exceptions;
+import org.apache.hadoop.io.Writable;
 
-public class BTreeDuplicateKeyException extends BTreeException {
-    private static final long serialVersionUID = 1L;
+/**
+ * @author yingyib
+ */
+public interface WritableSizable extends Writable, Sizable {
 
-    public BTreeDuplicateKeyException(Exception e) {
-        super(e);
-    }
-
-    public BTreeDuplicateKeyException(String message) {
-        super(message);
-    }
 }
diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/generated/GeneratedVertexInputFormat.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/generated/GeneratedVertexInputFormat.java
index 985bcff..1d3c427 100644
--- a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/generated/GeneratedVertexInputFormat.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/generated/GeneratedVertexInputFormat.java
@@ -26,13 +26,14 @@
 
 import edu.uci.ics.pregelix.api.io.BasicGenInputSplit;
 import edu.uci.ics.pregelix.api.io.VertexInputFormat;
+import edu.uci.ics.pregelix.api.io.WritableSizable;
 
 /**
  * This VertexInputFormat is meant for testing/debugging. It simply generates
  * some vertex data that can be consumed by test applications.
  */
 @SuppressWarnings("rawtypes")
-public abstract class GeneratedVertexInputFormat<I extends WritableComparable, V extends Writable, E extends Writable, M extends Writable>
+public abstract class GeneratedVertexInputFormat<I extends WritableComparable, V extends Writable, E extends Writable, M extends WritableSizable>
         extends VertexInputFormat<I, V, E, M> {
 
     @Override
diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/generated/GeneratedVertexReader.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/generated/GeneratedVertexReader.java
index 92c8728..376d45d 100644
--- a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/generated/GeneratedVertexReader.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/generated/GeneratedVertexReader.java
@@ -25,6 +25,7 @@
 
 import edu.uci.ics.pregelix.api.io.BasicGenInputSplit;
 import edu.uci.ics.pregelix.api.io.VertexReader;
+import edu.uci.ics.pregelix.api.io.WritableSizable;
 
 /**
  * Used by GeneratedVertexInputFormat to read some generated data
@@ -37,7 +38,7 @@
  *            Edge value
  */
 @SuppressWarnings("rawtypes")
-public abstract class GeneratedVertexReader<I extends WritableComparable, V extends Writable, E extends Writable, M extends Writable>
+public abstract class GeneratedVertexReader<I extends WritableComparable, V extends Writable, E extends Writable, M extends WritableSizable>
         implements VertexReader<I, V, E, M> {
     /** Records read so far */
     protected long recordsRead = 0;
diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/internal/InternalVertexInputFormat.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/internal/InternalVertexInputFormat.java
new file mode 100644
index 0000000..22d3b27
--- /dev/null
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/internal/InternalVertexInputFormat.java
@@ -0,0 +1,84 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.api.io.internal;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.apache.hadoop.io.Writable;
+import org.apache.hadoop.io.WritableComparable;
+import org.apache.hadoop.mapreduce.InputSplit;
+import org.apache.hadoop.mapreduce.JobContext;
+import org.apache.hadoop.mapreduce.RecordReader;
+import org.apache.hadoop.mapreduce.TaskAttemptContext;
+import org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat;
+
+import edu.uci.ics.pregelix.api.graph.Vertex;
+import edu.uci.ics.pregelix.api.io.VertexInputFormat;
+import edu.uci.ics.pregelix.api.io.VertexReader;
+import edu.uci.ics.pregelix.api.io.WritableSizable;
+
+/**
+ * @author yingyib
+ */
+@SuppressWarnings("rawtypes")
+public class InternalVertexInputFormat<I extends WritableComparable, V extends Writable, E extends Writable, M extends WritableSizable>
+        extends VertexInputFormat<I, V, E, M> {
+    /** Uses the SequenceFileInputFormat to do everything */
+    private SequenceFileInputFormat sequenceInputFormat = new SequenceFileInputFormat();
+
+    @SuppressWarnings("unchecked")
+    @Override
+    public List<InputSplit> getSplits(JobContext context, int numWorkers) throws IOException, InterruptedException {
+        return sequenceInputFormat.getSplits(context);
+    }
+
+    @Override
+    public VertexReader<I, V, E, M> createVertexReader(final InputSplit split, final TaskAttemptContext context)
+            throws IOException {
+        return new VertexReader<I, V, E, M>() {
+            RecordReader recordReader = sequenceInputFormat.createRecordReader(split, context);
+
+            @Override
+            public void initialize(InputSplit inputSplit, TaskAttemptContext context) throws IOException,
+                    InterruptedException {
+                recordReader.initialize(inputSplit, context);
+            }
+
+            @Override
+            public boolean nextVertex() throws IOException, InterruptedException {
+                return recordReader.nextKeyValue();
+            }
+
+            @SuppressWarnings("unchecked")
+            @Override
+            public Vertex<I, V, E, M> getCurrentVertex() throws IOException, InterruptedException {
+                return (Vertex<I, V, E, M>) recordReader.getCurrentValue();
+            }
+
+            @Override
+            public void close() throws IOException {
+                recordReader.close();
+            }
+
+            @Override
+            public float getProgress() throws IOException, InterruptedException {
+                return 0;
+            }
+
+        };
+    }
+
+}
diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/internal/InternalVertexOutputFormat.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/internal/InternalVertexOutputFormat.java
new file mode 100644
index 0000000..b603037
--- /dev/null
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/internal/InternalVertexOutputFormat.java
@@ -0,0 +1,111 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.api.io.internal;
+
+import java.io.IOException;
+
+import org.apache.hadoop.io.NullWritable;
+import org.apache.hadoop.io.Writable;
+import org.apache.hadoop.io.WritableComparable;
+import org.apache.hadoop.mapreduce.JobContext;
+import org.apache.hadoop.mapreduce.OutputCommitter;
+import org.apache.hadoop.mapreduce.RecordWriter;
+import org.apache.hadoop.mapreduce.TaskAttemptContext;
+import org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat;
+
+import edu.uci.ics.pregelix.api.graph.Vertex;
+import edu.uci.ics.pregelix.api.io.VertexOutputFormat;
+import edu.uci.ics.pregelix.api.io.VertexWriter;
+
+/**
+ * @author yingyib
+ */
+@SuppressWarnings("rawtypes")
+public class InternalVertexOutputFormat<I extends WritableComparable, V extends Writable, E extends Writable> extends
+        VertexOutputFormat<I, V, E> {
+    private SequenceFileOutputFormat sequenceOutputFormat = new SequenceFileOutputFormat();
+
+    @Override
+    public VertexWriter<I, V, E> createVertexWriter(final TaskAttemptContext context) throws IOException,
+            InterruptedException {
+        return new VertexWriter<I, V, E>() {
+            private RecordWriter recordWriter = sequenceOutputFormat.getRecordWriter(context);
+            private NullWritable key = NullWritable.get();
+
+            @Override
+            public void initialize(TaskAttemptContext context) throws IOException, InterruptedException {
+
+            }
+
+            @SuppressWarnings("unchecked")
+            @Override
+            public void writeVertex(Vertex<I, V, E, ?> vertex) throws IOException, InterruptedException {
+                recordWriter.write(key, vertex);
+            }
+
+            @Override
+            public void close(TaskAttemptContext context) throws IOException, InterruptedException {
+                recordWriter.close(context);
+            }
+
+        };
+    }
+
+    @Override
+    public void checkOutputSpecs(JobContext context) throws IOException, InterruptedException {
+
+    }
+
+    @Override
+    public OutputCommitter getOutputCommitter(TaskAttemptContext context) throws IOException, InterruptedException {
+        return new OutputCommitter() {
+
+            @Override
+            public void abortTask(TaskAttemptContext arg0) throws IOException {
+                // TODO Auto-generated method stub
+
+            }
+
+            @Override
+            public void cleanupJob(JobContext arg0) throws IOException {
+                // TODO Auto-generated method stub
+
+            }
+
+            @Override
+            public void commitTask(TaskAttemptContext arg0) throws IOException {
+                // TODO Auto-generated method stub
+
+            }
+
+            @Override
+            public boolean needsTaskCommit(TaskAttemptContext arg0) throws IOException {
+                return false;
+            }
+
+            @Override
+            public void setupJob(JobContext arg0) throws IOException {
+
+            }
+
+            @Override
+            public void setupTask(TaskAttemptContext arg0) throws IOException {
+
+            }
+
+        };
+    }
+
+}
diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/text/TextVertexInputFormat.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/text/TextVertexInputFormat.java
index 2254ae4..0faf516 100644
--- a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/text/TextVertexInputFormat.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/io/text/TextVertexInputFormat.java
@@ -30,6 +30,7 @@
 
 import edu.uci.ics.pregelix.api.io.VertexInputFormat;
 import edu.uci.ics.pregelix.api.io.VertexReader;
+import edu.uci.ics.pregelix.api.io.WritableSizable;
 
 /**
  * Abstract class that users should subclass to use their own text based vertex
@@ -45,7 +46,7 @@
  *            Message value
  */
 @SuppressWarnings("rawtypes")
-public abstract class TextVertexInputFormat<I extends WritableComparable, V extends Writable, E extends Writable, M extends Writable>
+public abstract class TextVertexInputFormat<I extends WritableComparable, V extends Writable, E extends Writable, M extends WritableSizable>
         extends VertexInputFormat<I, V, E, M> {
     /** Uses the TextInputFormat to do everything */
     protected TextInputFormat textInputFormat = new TextInputFormat();
@@ -62,7 +63,7 @@
      * @param <E>
      *            Edge value
      */
-    public static abstract class TextVertexReader<I extends WritableComparable, V extends Writable, E extends Writable, M extends Writable>
+    public static abstract class TextVertexReader<I extends WritableComparable, V extends Writable, E extends Writable, M extends WritableSizable>
             implements VertexReader<I, V, E, M> {
         /** Internal line record reader */
         private final RecordReader<LongWritable, Text> lineRecordReader;
diff --git a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/job/ICheckpointHook.java
similarity index 64%
copy from hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
copy to pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/job/ICheckpointHook.java
index cde5022..9d6eb5a 100644
--- a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/job/ICheckpointHook.java
@@ -12,17 +12,13 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+package edu.uci.ics.pregelix.api.job;
 
-package edu.uci.ics.hyracks.storage.am.btree.exceptions;
+/**
+ * @author yingyib
+ */
+public interface ICheckpointHook {
 
-public class BTreeDuplicateKeyException extends BTreeException {
-    private static final long serialVersionUID = 1L;
+    public boolean checkpoint(int superstep);
 
-    public BTreeDuplicateKeyException(Exception e) {
-        super(e);
-    }
-
-    public BTreeDuplicateKeyException(String message) {
-        super(message);
-    }
 }
diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/job/PregelixJob.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/job/PregelixJob.java
index 4cddaf0..6549c52 100644
--- a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/job/PregelixJob.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/job/PregelixJob.java
@@ -74,6 +74,22 @@
     public static final String FRAME_SIZE = "pregelix.framesize";
     /** update intensive */
     public static final String UPDATE_INTENSIVE = "pregelix.updateIntensive";
+    /** the check point hook */
+    public static final String CKP_CLASS = "pregelix.checkpointHook";
+    /** the check point hook */
+    public static final String RECOVERY_COUNT = "pregelix.recoveryCount";
+    /** the checkpoint interval */
+    public static final String CKP_INTERVAL = "pregelix.ckpinterval";
+
+    /**
+     * Construct a Pregelix job from an existing configuration
+     * 
+     * @param conf
+     * @throws IOException
+     */
+    public PregelixJob(Configuration conf) throws IOException {
+        super(conf);
+    }
 
     /**
      * Constructor that will instantiate the configuration
@@ -198,7 +214,39 @@
      * 
      * @param updateHeavyFlag
      */
-    final public void setMutationOrVariableSizedUpdateHeavy(boolean variableSizedUpdateHeavyFlag) {
+    final public void setLSMStorage(boolean variableSizedUpdateHeavyFlag) {
         getConfiguration().setBoolean(UPDATE_INTENSIVE, variableSizedUpdateHeavyFlag);
     }
+
+    /**
+     * Users can provide an ICheckpointHook implementation to specify when to do checkpoint
+     * 
+     * @param ckpClass
+     */
+    final public void setCheckpointHook(Class<?> ckpClass) {
+        getConfiguration().setClass(CKP_CLASS, ckpClass, ICheckpointHook.class);
+    }
+
+    /**
+     * Users can provide an ICheckpointHook implementation to specify when to do checkpoint
+     * 
+     * @param ckpClass
+     */
+    final public void setRecoveryCount(int recoveryCount) {
+        getConfiguration().setInt(RECOVERY_COUNT, recoveryCount);
+    }
+
+    /**
+     * Users can set the interval of checkpointing
+     * 
+     * @param ckpInterval
+     */
+    final public void setCheckpointingInterval(int ckpInterval) {
+        getConfiguration().setInt(CKP_INTERVAL, ckpInterval);
+    }
+
+    @Override
+    public String toString() {
+        return getJobName();
+    }
 }
diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/ArrayListWritable.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/ArrayListWritable.java
index 7a9e5d5..1683541 100644
--- a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/ArrayListWritable.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/ArrayListWritable.java
@@ -141,9 +141,6 @@
         used = 0;
         this.clear();
         int numValues = in.readInt(); // read number of values
-        if (numValues > 100) {
-            System.out.println("num values: " + numValues);
-        }
         for (int i = 0; i < numValues; i++) {
             M value = allocateValue();
             value.readFields(in); // read a value
@@ -153,9 +150,6 @@
 
     public void write(DataOutput out) throws IOException {
         int numValues = size();
-        if (numValues > 100) {
-            System.out.println("write num values: " + numValues);
-        }
         out.writeInt(numValues); // write number of values
         for (int i = 0; i < numValues; i++) {
             get(i).write(out);
diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/BspUtils.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/BspUtils.java
index 03c37dc..4ee1deb 100644
--- a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/BspUtils.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/BspUtils.java
@@ -28,6 +28,8 @@
 import edu.uci.ics.pregelix.api.graph.VertexPartitioner;
 import edu.uci.ics.pregelix.api.io.VertexInputFormat;
 import edu.uci.ics.pregelix.api.io.VertexOutputFormat;
+import edu.uci.ics.pregelix.api.io.WritableSizable;
+import edu.uci.ics.pregelix.api.job.ICheckpointHook;
 import edu.uci.ics.pregelix.api.job.PregelixJob;
 
 /**
@@ -49,7 +51,7 @@
      * @return User's vertex input format class
      */
     @SuppressWarnings({ "rawtypes", "unchecked" })
-    public static <I extends WritableComparable, V extends Writable, E extends Writable, M extends Writable> Class<? extends VertexInputFormat<I, V, E, M>> getVertexInputFormatClass(
+    public static <I extends WritableComparable, V extends Writable, E extends Writable, M extends WritableSizable> Class<? extends VertexInputFormat<I, V, E, M>> getVertexInputFormatClass(
             Configuration conf) {
         return (Class<? extends VertexInputFormat<I, V, E, M>>) conf.getClass(PregelixJob.VERTEX_INPUT_FORMAT_CLASS,
                 null, VertexInputFormat.class);
@@ -63,7 +65,7 @@
      * @return Instantiated user vertex input format class
      */
     @SuppressWarnings("rawtypes")
-    public static <I extends WritableComparable, V extends Writable, E extends Writable, M extends Writable> VertexInputFormat<I, V, E, M> createVertexInputFormat(
+    public static <I extends WritableComparable, V extends Writable, E extends Writable, M extends WritableSizable> VertexInputFormat<I, V, E, M> createVertexInputFormat(
             Configuration conf) {
         Class<? extends VertexInputFormat<I, V, E, M>> vertexInputFormatClass = getVertexInputFormatClass(conf);
         VertexInputFormat<I, V, E, M> inputFormat = ReflectionUtils.newInstance(vertexInputFormatClass, conf);
@@ -106,7 +108,7 @@
      * @return User's vertex combiner class
      */
     @SuppressWarnings({ "rawtypes", "unchecked" })
-    public static <I extends WritableComparable, M extends Writable, P extends Writable> Class<? extends MessageCombiner<I, M, P>> getMessageCombinerClass(
+    public static <I extends WritableComparable, M extends WritableSizable, P extends Writable> Class<? extends MessageCombiner<I, M, P>> getMessageCombinerClass(
             Configuration conf) {
         return (Class<? extends MessageCombiner<I, M, P>>) conf.getClass(PregelixJob.Message_COMBINER_CLASS,
                 DefaultMessageCombiner.class, MessageCombiner.class);
@@ -120,7 +122,7 @@
      * @return User's vertex combiner class
      */
     @SuppressWarnings({ "rawtypes", "unchecked" })
-    public static <I extends WritableComparable, V extends Writable, E extends Writable, M extends Writable, P extends Writable, F extends Writable> Class<? extends GlobalAggregator<I, V, E, M, P, F>> getGlobalAggregatorClass(
+    public static <I extends WritableComparable, V extends Writable, E extends Writable, M extends WritableSizable, P extends Writable, F extends Writable> Class<? extends GlobalAggregator<I, V, E, M, P, F>> getGlobalAggregatorClass(
             Configuration conf) {
         return (Class<? extends GlobalAggregator<I, V, E, M, P, F>>) conf.getClass(PregelixJob.GLOBAL_AGGREGATOR_CLASS,
                 GlobalCountAggregator.class, GlobalAggregator.class);
@@ -138,7 +140,7 @@
      * @return Instantiated user vertex combiner class
      */
     @SuppressWarnings("rawtypes")
-    public static <I extends WritableComparable, M extends Writable, P extends Writable> MessageCombiner<I, M, P> createMessageCombiner(
+    public static <I extends WritableComparable, M extends WritableSizable, P extends Writable> MessageCombiner<I, M, P> createMessageCombiner(
             Configuration conf) {
         Class<? extends MessageCombiner<I, M, P>> vertexCombinerClass = getMessageCombinerClass(conf);
         return ReflectionUtils.newInstance(vertexCombinerClass, conf);
@@ -164,7 +166,7 @@
      * @return Instantiated user vertex combiner class
      */
     @SuppressWarnings("rawtypes")
-    public static <I extends WritableComparable, V extends Writable, E extends Writable, M extends Writable, P extends Writable, F extends Writable> GlobalAggregator<I, V, E, M, P, F> createGlobalAggregator(
+    public static <I extends WritableComparable, V extends Writable, E extends Writable, M extends WritableSizable, P extends Writable, F extends Writable> GlobalAggregator<I, V, E, M, P, F> createGlobalAggregator(
             Configuration conf) {
         Class<? extends GlobalAggregator<I, V, E, M, P, F>> globalAggregatorClass = getGlobalAggregatorClass(conf);
         return ReflectionUtils.newInstance(globalAggregatorClass, conf);
@@ -178,7 +180,7 @@
      * @return User's vertex class
      */
     @SuppressWarnings({ "rawtypes", "unchecked" })
-    public static <I extends WritableComparable, V extends Writable, E extends Writable, M extends Writable> Class<? extends Vertex<I, V, E, M>> getVertexClass(
+    public static <I extends WritableComparable, V extends Writable, E extends Writable, M extends WritableSizable> Class<? extends Vertex<I, V, E, M>> getVertexClass(
             Configuration conf) {
         return (Class<? extends Vertex<I, V, E, M>>) conf.getClass(PregelixJob.VERTEX_CLASS, null, Vertex.class);
     }
@@ -191,7 +193,7 @@
      * @return Instantiated user vertex
      */
     @SuppressWarnings("rawtypes")
-    public static <I extends WritableComparable, V extends Writable, E extends Writable, M extends Writable> Vertex<I, V, E, M> createVertex(
+    public static <I extends WritableComparable, V extends Writable, E extends Writable, M extends WritableSizable> Vertex<I, V, E, M> createVertex(
             Configuration conf) {
         Class<? extends Vertex<I, V, E, M>> vertexClass = getVertexClass(conf);
         Vertex<I, V, E, M> vertex = ReflectionUtils.newInstance(vertexClass, conf);
@@ -299,7 +301,7 @@
      * @return User's vertex message value class
      */
     @SuppressWarnings("unchecked")
-    public static <M extends Writable> Class<M> getMessageValueClass(Configuration conf) {
+    public static <M extends WritableSizable> Class<M> getMessageValueClass(Configuration conf) {
         if (conf == null)
             conf = defaultConf;
         return (Class<M>) conf.getClass(PregelixJob.MESSAGE_VALUE_CLASS, Writable.class);
@@ -369,7 +371,7 @@
      *            Configuration to check
      * @return Instantiated user vertex message value
      */
-    public static <M extends Writable> M createMessageValue(Configuration conf) {
+    public static <M extends WritableSizable> M createMessageValue(Configuration conf) {
         Class<M> messageValueClass = getMessageValueClass(conf);
         try {
             return messageValueClass.newInstance();
@@ -460,6 +462,24 @@
     }
 
     /**
+     * Create a checkpoint hook
+     * 
+     * @param conf
+     *            Configuration to check
+     * @return Instantiated user aggregate value
+     */
+    public static ICheckpointHook createCheckpointHook(Configuration conf) {
+        Class<? extends ICheckpointHook> ckpClass = getCheckpointHookClass(conf);
+        try {
+            return ckpClass.newInstance();
+        } catch (InstantiationException e) {
+            throw new IllegalArgumentException("createVertexPartitioner: Failed to instantiate", e);
+        } catch (IllegalAccessException e) {
+            throw new IllegalArgumentException("createVertexPartitioner: Illegally accessed", e);
+        }
+    }
+
+    /**
      * Get the user's subclassed vertex partitioner class.
      * 
      * @param conf
@@ -474,6 +494,20 @@
     }
 
     /**
+     * Get the user's subclassed checkpoint hook class.
+     * 
+     * @param conf
+     *            Configuration to check
+     * @return The user defined vertex checkpoint hook class
+     */
+    @SuppressWarnings("unchecked")
+    public static <V extends ICheckpointHook> Class<V> getCheckpointHookClass(Configuration conf) {
+        if (conf == null)
+            conf = defaultConf;
+        return (Class<V>) conf.getClass(PregelixJob.CKP_CLASS, DefaultCheckpointHook.class, ICheckpointHook.class);
+    }
+
+    /**
      * Get the job configuration parameter whether the vertex states will increase dynamically
      * 
      * @param conf
@@ -504,4 +538,68 @@
     public static boolean useLSM(Configuration conf) {
         return conf.getBoolean(PregelixJob.UPDATE_INTENSIVE, false);
     }
+
+    /***
+     * Get the spilling dir name for global aggregates
+     * 
+     * @param conf
+     * @param superStep
+     * @return the spilling dir name
+     */
+    public static String getGlobalAggregateSpillingDirName(Configuration conf, long superStep) {
+        return "/tmp/pregelix/agg/" + conf.get(PregelixJob.JOB_ID) + "/" + superStep;
+    }
+
+    /**
+     * Get the path for vertex checkpointing
+     * 
+     * @param conf
+     * @param lastSuperStep
+     * @return the path for vertex checkpointing
+     */
+    public static String getVertexCheckpointPath(Configuration conf, long lastSuperStep) {
+        return "/tmp/ckpoint/" + BspUtils.getJobId(conf) + "/vertex/" + lastSuperStep;
+    }
+
+    /**
+     * Get the path for message checkpointing
+     * 
+     * @param conf
+     * @param lastSuperStep
+     * @return the path for message checkpointing
+     */
+    public static String getMessageCheckpointPath(Configuration conf, long lastSuperStep) {
+        String path = "/tmp/ckpoint/" + BspUtils.getJobId(conf) + "/message/" + lastSuperStep;
+        return path;
+    }
+
+    /**
+     * Get the path for message checkpointing
+     * 
+     * @param conf
+     * @param lastSuperStep
+     * @return the path for message checkpointing
+     */
+    public static String getSecondaryIndexCheckpointPath(Configuration conf, long lastSuperStep) {
+        return "/tmp/ckpoint/" + BspUtils.getJobId(conf) + "/secondaryindex/" + lastSuperStep;
+    }
+
+    /***
+     * Get the recovery count
+     * 
+     * @return recovery count
+     */
+    public static int getRecoveryCount(Configuration conf) {
+        return conf.getInt(PregelixJob.RECOVERY_COUNT, 0);
+    }
+
+    /***
+     * Get the user-set checkpoint interval
+     * 
+     * @param conf
+     * @return the checkpoint interval
+     */
+    public static int getCheckpointingInterval(Configuration conf) {
+        return conf.getInt(PregelixJob.CKP_INTERVAL, -1);
+    }
 }
diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/ConservativeCheckpointHook.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/ConservativeCheckpointHook.java
new file mode 100644
index 0000000..4f5fef0
--- /dev/null
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/ConservativeCheckpointHook.java
@@ -0,0 +1,35 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.api.util;
+
+import edu.uci.ics.pregelix.api.job.ICheckpointHook;
+
+/**
+ * A conservative checkpoint hook which does checkpoint every 5 supersteps
+ * 
+ * @author yingyib
+ */
+public class ConservativeCheckpointHook implements ICheckpointHook {
+
+    @Override
+    public boolean checkpoint(int superstep) {
+        if (superstep % 2 == 0) {
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+}
diff --git a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/DefaultCheckpointHook.java
similarity index 65%
copy from hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
copy to pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/DefaultCheckpointHook.java
index cde5022..c37c4ab 100644
--- a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/DefaultCheckpointHook.java
@@ -12,17 +12,20 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+package edu.uci.ics.pregelix.api.util;
 
-package edu.uci.ics.hyracks.storage.am.btree.exceptions;
+import edu.uci.ics.pregelix.api.job.ICheckpointHook;
 
-public class BTreeDuplicateKeyException extends BTreeException {
-    private static final long serialVersionUID = 1L;
+/**
+ * The default checkpoint hook which never does checkpointing.
+ * 
+ * @author yingyib
+ */
+public class DefaultCheckpointHook implements ICheckpointHook {
 
-    public BTreeDuplicateKeyException(Exception e) {
-        super(e);
+    @Override
+    public boolean checkpoint(int superstep) {
+        return false;
     }
 
-    public BTreeDuplicateKeyException(String message) {
-        super(message);
-    }
 }
diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/DefaultMessageCombiner.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/DefaultMessageCombiner.java
index d2d90a2..feb9e2f 100644
--- a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/DefaultMessageCombiner.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/DefaultMessageCombiner.java
@@ -14,42 +14,82 @@
  */
 package edu.uci.ics.pregelix.api.util;
 
-import org.apache.hadoop.io.Writable;
 import org.apache.hadoop.io.WritableComparable;
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.pregelix.api.graph.MessageCombiner;
 import edu.uci.ics.pregelix.api.graph.MsgList;
+import edu.uci.ics.pregelix.api.io.WritableSizable;
 
 @SuppressWarnings({ "rawtypes", "unchecked" })
-public class DefaultMessageCombiner<I extends WritableComparable, M extends Writable> extends
+public class DefaultMessageCombiner<I extends WritableComparable, M extends WritableSizable> extends
         MessageCombiner<I, M, MsgList> {
     private MsgList<M> msgList;
+    private int metaSlot = 8;
+    private int accumulatedSize = metaSlot;
 
     @Override
     public void init(MsgList providedMsgList) {
+        realInit(providedMsgList);
+        this.msgList.setSegmentStart(false);
+    }
+
+    private void realInit(MsgList providedMsgList) {
         this.msgList = providedMsgList;
         this.msgList.clearElements();
+        this.accumulatedSize = metaSlot;
     }
 
     @Override
     public void stepPartial(I vertexIndex, M msg) throws HyracksDataException {
         msgList.addElement(msg);
+        accumulatedSize += msg.sizeInBytes();
     }
 
     @Override
     public void stepFinal(I vertexIndex, MsgList partialAggregate) throws HyracksDataException {
         msgList.addAllElements(partialAggregate);
+        for (int i = 0; i < partialAggregate.size(); i++) {
+            accumulatedSize += ((M) partialAggregate.get(i)).sizeInBytes();
+        }
     }
 
     @Override
     public MsgList finishPartial() {
+        msgList.setSegmentEnd(false);
         return msgList;
     }
 
     @Override
     public MsgList<M> finishFinal() {
+        msgList.setSegmentEnd(false);
         return msgList;
     }
 
+    @Override
+    public void initAll(MsgList providedMsgList) {
+        realInit(providedMsgList);
+        msgList.setSegmentStart(true);
+    }
+
+    @Override
+    public MsgList<M> finishFinalAll() {
+        msgList.setSegmentEnd(true);
+        return msgList;
+    }
+
+    @Override
+    public int estimateAccumulatedStateByteSizePartial(I vertexIndex, M msg) throws HyracksDataException {
+        return accumulatedSize + msg.sizeInBytes();
+    }
+
+    @Override
+    public int estimateAccumulatedStateByteSizeFinal(I vertexIndex, MsgList partialAggregate)
+            throws HyracksDataException {
+        int size = accumulatedSize;
+        for (int i = 0; i < partialAggregate.size(); i++) {
+            size += ((M) partialAggregate.get(i)).sizeInBytes();
+        }
+        return size;
+    }
 }
diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/FrameTupleUtils.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/FrameTupleUtils.java
index 24105ae..a0f67e3 100644
--- a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/FrameTupleUtils.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/FrameTupleUtils.java
@@ -15,6 +15,14 @@
 
 package edu.uci.ics.pregelix.api.util;
 
+import java.io.IOException;
+import java.util.UUID;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FSDataOutputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+
 import edu.uci.ics.hyracks.api.comm.IFrameWriter;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
@@ -41,4 +49,19 @@
         }
     }
 
+    public static void flushTupleToHDFS(ArrayTupleBuilder atb, Configuration conf, long superStep)
+            throws HyracksDataException {
+        try {
+            if (atb.getSize()>0) {
+                FileSystem dfs = FileSystem.get(conf);
+                String fileName = BspUtils.getGlobalAggregateSpillingDirName(conf, superStep) +"/" + UUID.randomUUID();
+                FSDataOutputStream dos = dfs.create(new Path(fileName), true);
+                dos.write(atb.getByteArray(), 0, atb.getSize());
+                dos.flush();
+                dos.close();
+            }
+        } catch (IOException e) {
+            throw new HyracksDataException(e);
+        }
+    }
 }
diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/GlobalCountAggregator.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/GlobalCountAggregator.java
index ffc6526..9a95f09 100644
--- a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/GlobalCountAggregator.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/GlobalCountAggregator.java
@@ -21,9 +21,10 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.pregelix.api.graph.GlobalAggregator;
 import edu.uci.ics.pregelix.api.graph.Vertex;
+import edu.uci.ics.pregelix.api.io.WritableSizable;
 
 @SuppressWarnings("rawtypes")
-public class GlobalCountAggregator<I extends WritableComparable, V extends Writable, E extends Writable, M extends Writable>
+public class GlobalCountAggregator<I extends WritableComparable, V extends Writable, E extends Writable, M extends WritableSizable>
         extends GlobalAggregator<I, V, E, M, LongWritable, LongWritable> {
 
     private LongWritable state = new LongWritable(0);
diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/JobStateUtils.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/JobStateUtils.java
new file mode 100644
index 0000000..4a98167
--- /dev/null
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/JobStateUtils.java
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.api.util;
+
+import java.io.IOException;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FSDataOutputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+
+/**
+ * @author yingyib
+ */
+public class JobStateUtils {
+
+    public static final String TMP_DIR = "/tmp/";
+
+    public static void writeForceTerminationState(Configuration conf, String jobId) throws HyracksDataException {
+        try {
+            FileSystem dfs = FileSystem.get(conf);
+            String pathStr = TMP_DIR + jobId + "fterm";
+            Path path = new Path(pathStr);
+            if (!dfs.exists(path)) {
+                FSDataOutputStream output = dfs.create(path, true);
+                output.writeBoolean(true);
+                output.flush();
+                output.close();
+            }
+        } catch (IOException e) {
+            throw new HyracksDataException(e);
+        }
+    }
+
+    public static boolean readForceTerminationState(Configuration conf, String jobId) throws HyracksDataException {
+        try {
+            FileSystem dfs = FileSystem.get(conf);
+            String pathStr = TMP_DIR + jobId + "fterm";
+            Path path = new Path(pathStr);
+            if (dfs.exists(path)) {
+                return true;
+            } else {
+                return false;
+            }
+        } catch (IOException e) {
+            throw new HyracksDataException(e);
+        }
+    }
+
+}
diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/ResetableByteArrayInputStream.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/ResetableByteArrayInputStream.java
index 7d5f627..c7febc1 100755
--- a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/ResetableByteArrayInputStream.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/ResetableByteArrayInputStream.java
@@ -15,11 +15,8 @@
 package edu.uci.ics.pregelix.api.util;
 
 import java.io.InputStream;
-import java.util.logging.Level;
-import java.util.logging.Logger;
 
 public class ResetableByteArrayInputStream extends InputStream {
-    private static final Logger LOGGER = Logger.getLogger(ResetableByteArrayInputStream.class.getName());
 
     private byte[] data;
     private int position;
@@ -36,19 +33,12 @@
     public int read() {
         int remaining = data.length - position;
         int value = remaining > 0 ? (data[position++] & 0xff) : -1;
-        if (LOGGER.isLoggable(Level.FINEST)) {
-            LOGGER.finest("read(): value: " + value + " remaining: " + remaining + " position: " + position);
-        }
         return value;
     }
 
     @Override
     public int read(byte[] bytes, int offset, int length) {
         int remaining = data.length - position;
-        if (LOGGER.isLoggable(Level.FINEST)) {
-            LOGGER.finest("read(bytes[], int, int): remaining: " + remaining + " offset: " + offset + " length: "
-                    + length + " position: " + position);
-        }
         if (remaining == 0) {
             return -1;
         }
@@ -57,4 +47,9 @@
         position += l;
         return l;
     }
-}
\ No newline at end of file
+
+    @Override
+    public int available() {
+        return data.length - position;
+    }
+}
diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/SerDeUtils.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/SerDeUtils.java
index 25b07ff..a4336a3 100644
--- a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/SerDeUtils.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/SerDeUtils.java
@@ -40,47 +40,4 @@
         object.readFields(input);
     }
 
-    public static long readVLong(DataInput in) throws IOException {
-        int vLen = 0;
-        long value = 0L;
-        while (true) {
-            byte b = (byte) in.readByte();
-            ++vLen;
-            value += (((long) (b & 0x7f)) << ((vLen - 1) * 7));
-            if ((b & 0x80) == 0) {
-                break;
-            }
-        }
-        return value;
-    }
-
-    public static void writeVLong(DataOutput out, long value) throws IOException {
-        long data = value;
-        do {
-            byte b = (byte) (data & 0x7f);
-            data >>= 7;
-            if (data != 0) {
-                b |= 0x80;
-            }
-            out.write(b);
-        } while (data != 0);
-    }
-
-    public static long readVLong(byte[] data, int start, int length) {
-        int vLen = 0;
-        long value = 0L;
-        while (true) {
-            byte b = (byte) data[start];
-            ++vLen;
-            value += (((long) (b & 0x7f)) << ((vLen - 1) * 7));
-            if ((b & 0x80) == 0) {
-                break;
-            }
-            ++start;
-        }
-        if (vLen != length)
-            throw new IllegalStateException("length mismatch -- vLen:" + vLen + " length:" + length);
-        return value;
-    }
-
 }
diff --git a/pregelix/pregelix-benchmark/pom.xml b/pregelix/pregelix-benchmark/pom.xml
new file mode 100644
index 0000000..4d7d456
--- /dev/null
+++ b/pregelix/pregelix-benchmark/pom.xml
@@ -0,0 +1,36 @@
+<?xml version="1.0"?>
+<project
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<artifactId>pregelix</artifactId>
+		<groupId>edu.uci.ics.hyracks</groupId>
+		<version>0.2.10-SNAPSHOT</version>
+	</parent>
+
+	<artifactId>pregelix-benchmark</artifactId>
+	<name>pregelix-benchmark</name>
+	<url>http://maven.apache.org</url>
+	<dependencies>
+		<dependency>
+			<groupId>junit</groupId>
+			<artifactId>junit</artifactId>
+			<version>3.8.1</version>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.giraph</groupId>
+			<artifactId>giraph-core</artifactId>
+			<version>1.0.0</version>
+			<scope>compile</scope>
+		</dependency>
+		<dependency>
+			<groupId>edu.uci.ics.hyracks</groupId>
+			<artifactId>hyracks-hdfs-core</artifactId>
+			<version>0.2.10-SNAPSHOT</version>
+			<type>jar</type>
+			<scope>compile</scope>
+		</dependency>
+	</dependencies>
+</project>
diff --git a/pregelix/pregelix-benchmark/src/main/java/edu/uci/ics/pregelix/benchmark/PageRankVertex.java b/pregelix/pregelix-benchmark/src/main/java/edu/uci/ics/pregelix/benchmark/PageRankVertex.java
new file mode 100644
index 0000000..04c29de
--- /dev/null
+++ b/pregelix/pregelix-benchmark/src/main/java/edu/uci/ics/pregelix/benchmark/PageRankVertex.java
@@ -0,0 +1,58 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.pregelix.benchmark;
+
+import org.apache.giraph.graph.Vertex;
+import org.apache.hadoop.io.DoubleWritable;
+import org.apache.hadoop.io.FloatWritable;
+import org.apache.hadoop.io.VLongWritable;
+
+/**
+ * Demonstrates the basic Pregel PageRank implementation.
+ */
+public class PageRankVertex extends Vertex<VLongWritable, DoubleWritable, FloatWritable, DoubleWritable> {
+
+    public static final String ITERATIONS = "HyracksPageRankVertex.iteration";
+    private final DoubleWritable vertexValue = new DoubleWritable();
+    private final DoubleWritable msg = new DoubleWritable();
+    private int maxIteration = -1;
+
+    @Override
+    public void compute(Iterable<DoubleWritable> msgIterator) {
+        if (maxIteration < 0) {
+            maxIteration = getContext().getConfiguration().getInt(ITERATIONS, 10);
+        }
+        if (getSuperstep() == 1) {
+            vertexValue.set(1.0 / getTotalNumVertices());
+        }
+        if (getSuperstep() >= 2 && getSuperstep() <= maxIteration) {
+            double sum = 0;
+            for (DoubleWritable msg : msgIterator) {
+                sum += msg.get();
+            }
+            vertexValue.set((0.15 / getTotalNumVertices()) + 0.85 * sum);
+        }
+
+        if (getSuperstep() >= 1 && getSuperstep() < maxIteration) {
+            long edges = getNumEdges();
+            msg.set(vertexValue.get() / edges);
+            sendMessageToAllEdges(msg);
+        } else {
+            voteToHalt();
+        }
+    }
+
+}
diff --git a/pregelix/pregelix-benchmark/src/main/java/edu/uci/ics/pregelix/benchmark/TextPageRankInputFormat.java b/pregelix/pregelix-benchmark/src/main/java/edu/uci/ics/pregelix/benchmark/TextPageRankInputFormat.java
new file mode 100644
index 0000000..3d85f66
--- /dev/null
+++ b/pregelix/pregelix-benchmark/src/main/java/edu/uci/ics/pregelix/benchmark/TextPageRankInputFormat.java
@@ -0,0 +1,70 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.benchmark;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+
+import org.apache.giraph.edge.Edge;
+import org.apache.giraph.edge.MapMutableEdge;
+import org.apache.giraph.io.formats.TextVertexInputFormat;
+import org.apache.hadoop.io.DoubleWritable;
+import org.apache.hadoop.io.FloatWritable;
+import org.apache.hadoop.io.Text;
+import org.apache.hadoop.io.VLongWritable;
+import org.apache.hadoop.mapreduce.InputSplit;
+import org.apache.hadoop.mapreduce.TaskAttemptContext;
+
+public class TextPageRankInputFormat extends TextVertexInputFormat<VLongWritable, DoubleWritable, FloatWritable> {
+
+    @Override
+    public TextVertexReader createVertexReader(InputSplit split, TaskAttemptContext context) throws IOException {
+        return new TextVertexReaderFromEachLine() {
+            String[] items;
+
+            @Override
+            protected VLongWritable getId(Text line) throws IOException {
+                items = line.toString().split(" ");
+                return new VLongWritable(Long.parseLong(items[0]));
+            }
+
+            @Override
+            protected DoubleWritable getValue(Text line) throws IOException {
+                return null;
+            }
+
+            @Override
+            protected Iterable<Edge<VLongWritable, FloatWritable>> getEdges(Text line) throws IOException {
+                List<Edge<VLongWritable, FloatWritable>> edges = new ArrayList<Edge<VLongWritable, FloatWritable>>();
+                Map<VLongWritable, FloatWritable> edgeMap = new HashMap<VLongWritable, FloatWritable>();
+                for (int i = 1; i < items.length; i++) {
+                    edgeMap.put(new VLongWritable(Long.parseLong(items[i])), null);
+                }
+                for (Entry<VLongWritable, FloatWritable> entry : edgeMap.entrySet()) {
+                    MapMutableEdge<VLongWritable, FloatWritable> edge = new MapMutableEdge<VLongWritable, FloatWritable>();
+                    edge.setEntry(entry);
+                    edge.setValue(null);
+                    edges.add(edge);
+                }
+                return edges;
+            }
+
+        };
+    }
+}
diff --git a/pregelix/pregelix-core/pom.xml b/pregelix/pregelix-core/pom.xml
index 2a3efcf..3d1699f 100644
--- a/pregelix/pregelix-core/pom.xml
+++ b/pregelix/pregelix-core/pom.xml
@@ -21,7 +21,7 @@
 	<parent>
 		<groupId>edu.uci.ics.hyracks</groupId>
 		<artifactId>pregelix</artifactId>
-		<version>0.2.7-SNAPSHOT</version>
+		<version>0.2.10-SNAPSHOT</version>
 	</parent>
 
 
@@ -90,21 +90,55 @@
                 <version>1.3</version>
 				<executions>
 					<execution>
+						<id>pregelix</id>
 						<configuration>
+							<platforms>
+								<platform>unix</platform>
+							</platforms>
 							<programs>
 								<program>
 									<mainClass>org.apache.hadoop.util.RunJar</mainClass>
-									<name>pregelix-obselete</name>
+									<name>pregelix</name>
 								</program>
 							</programs>
 							<repositoryLayout>flat</repositoryLayout>
 							<repositoryName>lib</repositoryName>
+							<configurationDirectory>etc:"$HADOOP_HOME"/conf:/etc/hadoop/conf:"$1"</configurationDirectory>
 						</configuration>
 						<phase>package</phase>
 						<goals>
 							<goal>assemble</goal>
 						</goals>
 					</execution>
+					<execution>
+						<id>cc_nc_drivers</id>
+						<configuration>
+							<platforms>
+								<platform>unix</platform>
+							</platforms>
+							<programs>
+								<program>
+									<mainClass>edu.uci.ics.hyracks.control.cc.CCDriver</mainClass>
+									<name>pregelixcc</name>
+								</program>
+								<program>
+									<mainClass>edu.uci.ics.hyracks.control.nc.NCDriver</mainClass>
+									<name>pregelixnc</name>
+									<commandLineArguments>
+										<commandLineArgument>-app-nc-main-class</commandLineArgument>
+										<commandLineArgument>edu.uci.ics.pregelix.runtime.bootstrap.NCApplicationEntryPoint</commandLineArgument>
+									</commandLineArguments>
+								</program>
+							</programs>
+							<repositoryLayout>flat</repositoryLayout>
+							<repositoryName>lib</repositoryName>
+							<configurationDirectory>etc:"$HADOOP_HOME"/conf:/etc/hadoop/conf</configurationDirectory>
+						</configuration>
+						<phase>package</phase>
+						<goals>
+							<goal>assemble</goal>
+						</goals>
+					</execution>					
 				</executions>
 			</plugin>
 			<plugin>
@@ -209,84 +243,84 @@
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>pregelix-api</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>pregelix-dataflow-std</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>pregelix-dataflow</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-dataflow-std</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>pregelix-runtime</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-api</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-dataflow-common</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-data-std</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-storage-am-common</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-storage-am-btree</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-control-cc</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-control-nc</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
@@ -300,7 +334,7 @@
 		<dependency>
 			<groupId>edu.uci.ics.hyracks.examples</groupId>
 			<artifactId>hyracks-integration-tests</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<scope>test</scope>
 		</dependency>
 		<dependency>
@@ -320,7 +354,7 @@
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-ipc</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
diff --git a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/base/IDriver.java b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/base/IDriver.java
index bc6c0cf..c72f392 100644
--- a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/base/IDriver.java
+++ b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/base/IDriver.java
@@ -15,6 +15,8 @@
 
 package edu.uci.ics.pregelix.core.base;
 
+import java.util.List;
+
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 import edu.uci.ics.pregelix.api.job.PregelixJob;
 
@@ -29,6 +31,11 @@
 
     public void runJob(PregelixJob job, String ipAddress, int port) throws HyracksException;
 
+    public void runJobs(List<PregelixJob> jobs, String ipAddress, int port) throws HyracksException;
+
     public void runJob(PregelixJob job, Plan planChoice, String ipAddress, int port, boolean profiling)
             throws HyracksException;
+
+    public void runJobs(List<PregelixJob> jobs, Plan planChoice, String ipAddress, int port, boolean profiling)
+            throws HyracksException;
 }
diff --git a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/base/IJobGen.java b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/base/IJobGen.java
index 2d58902..6bb0dea 100644
--- a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/base/IJobGen.java
+++ b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/base/IJobGen.java
@@ -26,4 +26,10 @@
 
     public JobSpecification generateJob(int iteration) throws HyracksException;
 
+    public JobSpecification[] generateCheckpointing(int lastSuccessfulIteration) throws HyracksException;
+
+    public JobSpecification[] generateLoadingCheckpoint(int lastCheckpointedIteration) throws HyracksException;
+
+    public JobSpecification generateClearState() throws HyracksException;
+
 }
diff --git a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/driver/Driver.java b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/driver/Driver.java
index 2d4064b..d6a6f3d 100644
--- a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/driver/Driver.java
+++ b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/driver/Driver.java
@@ -17,15 +17,22 @@
 
 import java.io.File;
 import java.io.FilenameFilter;
+import java.io.IOException;
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.EnumSet;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.io.IntWritable;
+import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
 import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
 
 import edu.uci.ics.hyracks.api.client.HyracksConnection;
@@ -35,7 +42,9 @@
 import edu.uci.ics.hyracks.api.job.JobFlag;
 import edu.uci.ics.hyracks.api.job.JobId;
 import edu.uci.ics.hyracks.api.job.JobSpecification;
+import edu.uci.ics.pregelix.api.job.ICheckpointHook;
 import edu.uci.ics.pregelix.api.job.PregelixJob;
+import edu.uci.ics.pregelix.api.util.BspUtils;
 import edu.uci.ics.pregelix.core.base.IDriver;
 import edu.uci.ics.pregelix.core.jobgen.JobGen;
 import edu.uci.ics.pregelix.core.jobgen.JobGenInnerJoin;
@@ -43,16 +52,15 @@
 import edu.uci.ics.pregelix.core.jobgen.JobGenOuterJoinSingleSort;
 import edu.uci.ics.pregelix.core.jobgen.JobGenOuterJoinSort;
 import edu.uci.ics.pregelix.core.jobgen.clusterconfig.ClusterConfig;
+import edu.uci.ics.pregelix.core.util.ExceptionUtilities;
 import edu.uci.ics.pregelix.dataflow.util.IterationUtils;
 
 @SuppressWarnings("rawtypes")
 public class Driver implements IDriver {
     private static final Log LOG = LogFactory.getLog(Driver.class);
-    private JobGen jobGen;
-    private boolean profiling;
-
     private IHyracksClientConnection hcc;
     private Class exampleClass;
+    private boolean profiling = false;
 
     public Driver(Class exampleClass) {
         this.exampleClass = exampleClass;
@@ -64,93 +72,251 @@
     }
 
     @Override
+    public void runJobs(List<PregelixJob> jobs, String ipAddress, int port) throws HyracksException {
+        runJobs(jobs, Plan.OUTER_JOIN, ipAddress, port, false);
+    }
+
+    @Override
     public void runJob(PregelixJob job, Plan planChoice, String ipAddress, int port, boolean profiling)
             throws HyracksException {
+        runJobs(Collections.singletonList(job), planChoice, ipAddress, port, profiling);
+    }
+
+    @Override
+    public void runJobs(List<PregelixJob> jobs, Plan planChoice, String ipAddress, int port, boolean profiling)
+            throws HyracksException {
         try {
-            /** add hadoop configurations */
-            URL hadoopCore = job.getClass().getClassLoader().getResource("core-site.xml");
-            if (hadoopCore != null) {
-                job.getConfiguration().addResource(hadoopCore);
+            if (jobs.size() <= 0) {
+                throw new HyracksException("Please submit at least one job for execution!");
             }
-            URL hadoopMapRed = job.getClass().getClassLoader().getResource("mapred-site.xml");
-            if (hadoopMapRed != null) {
-                job.getConfiguration().addResource(hadoopMapRed);
-            }
-            URL hadoopHdfs = job.getClass().getClassLoader().getResource("hdfs-site.xml");
-            if (hadoopHdfs != null) {
-                job.getConfiguration().addResource(hadoopHdfs);
-            }
-            ClusterConfig.loadClusterConfig(ipAddress, port);
-
-            LOG.info("job started");
-            long start = System.currentTimeMillis();
-            long end = start;
-            long time = 0;
-
             this.profiling = profiling;
+            PregelixJob currentJob = jobs.get(0);
+            PregelixJob lastJob = currentJob;
+            addHadoopConfiguration(currentJob, ipAddress, port, true);
+            JobGen jobGen = null;
 
-            switch (planChoice) {
-                case INNER_JOIN:
-                    jobGen = new JobGenInnerJoin(job);
-                    break;
-                case OUTER_JOIN:
-                    jobGen = new JobGenOuterJoin(job);
-                    break;
-                case OUTER_JOIN_SORT:
-                    jobGen = new JobGenOuterJoinSort(job);
-                    break;
-                case OUTER_JOIN_SINGLE_SORT:
-                    jobGen = new JobGenOuterJoinSingleSort(job);
-                    break;
-                default:
-                    jobGen = new JobGenInnerJoin(job);
-            }
+            /** prepare job -- deploy jars */
+            DeploymentId deploymentId = prepareJobs(ipAddress, port);
+            LOG.info("job started");
 
-            if (hcc == null)
-                hcc = new HyracksConnection(ipAddress, port);
+            IntWritable lastSnapshotJobIndex = new IntWritable(0);
+            IntWritable lastSnapshotSuperstep = new IntWritable(0);
+            boolean failed = false;
+            int retryCount = 0;
+            int maxRetryCount = 3;
+            jobGen = selectJobGen(planChoice, currentJob);
 
-            URLClassLoader classLoader = (URLClassLoader) exampleClass.getClassLoader();
-            List<File> jars = new ArrayList<File>();
-            URL[] urls = classLoader.getURLs();
-            for (URL url : urls)
-                if (url.toString().endsWith(".jar"))
-                    jars.add(new File(url.getPath()));
-            DeploymentId deploymentId = installApplication(jars);
-
-            start = System.currentTimeMillis();
-            FileSystem dfs = FileSystem.get(job.getConfiguration());
-            dfs.delete(FileOutputFormat.getOutputPath(job), true);
-            runCreate(deploymentId, jobGen);
-            runDataLoad(deploymentId, jobGen);
-            end = System.currentTimeMillis();
-            time = end - start;
-            LOG.info("data loading finished " + time + "ms");
-            int i = 1;
-            boolean terminate = false;
             do {
-                start = System.currentTimeMillis();
-                runLoopBodyIteration(deploymentId, jobGen, i);
-                end = System.currentTimeMillis();
-                time = end - start;
-                LOG.info("iteration " + i + " finished " + time + "ms");
-                terminate = IterationUtils.readTerminationState(job.getConfiguration(), jobGen.getJobId())
-                        || IterationUtils.readForceTerminationState(job.getConfiguration(), jobGen.getJobId());
-                i++;
-            } while (!terminate);
+                try {
+                    for (int i = lastSnapshotJobIndex.get(); i < jobs.size(); i++) {
+                        lastJob = currentJob;
+                        currentJob = jobs.get(i);
+                        currentJob.setRecoveryCount(retryCount);
 
-            start = System.currentTimeMillis();
-            runHDFSWRite(deploymentId, jobGen);
-            runCleanup(deploymentId, jobGen);
-            end = System.currentTimeMillis();
-            time = end - start;
-            LOG.info("result writing finished " + time + "ms");
-            hcc.unDeployBinary(deploymentId);
+                        /** add hadoop configurations */
+                        addHadoopConfiguration(currentJob, ipAddress, port, failed);
+                        ICheckpointHook ckpHook = BspUtils.createCheckpointHook(currentJob.getConfiguration());
+
+                        /** load the data */
+                        if ((i == 0 || compatible(lastJob, currentJob)) && !failed) {
+                            if (i != 0) {
+                                finishJobs(jobGen, deploymentId);
+                                /** invalidate/clear checkpoint */
+                                lastSnapshotJobIndex.set(0);
+                                lastSnapshotSuperstep.set(0);
+                            }
+                            jobGen.reset(currentJob);
+                            loadData(currentJob, jobGen, deploymentId);
+                        } else {
+                            jobGen.reset(currentJob);
+                        }
+
+                        /** run loop-body jobs */
+                        runLoopBody(deploymentId, currentJob, jobGen, i, lastSnapshotJobIndex, lastSnapshotSuperstep,
+                                ckpHook, failed);
+                        runClearState(deploymentId, jobGen);
+                        failed = false;
+                    }
+
+                    /** finish the jobs */
+                    finishJobs(jobGen, deploymentId);
+                    /** clear checkpoints if any */
+                    jobGen.clearCheckpoints();
+                    hcc.unDeployBinary(deploymentId);
+                } catch (Exception e1) {
+                    Set<String> blackListNodes = new HashSet<String>();
+                    /** disk failures or node failures */
+                    if (ExceptionUtilities.recoverable(e1, blackListNodes)) {
+                        ClusterConfig.addToBlackListNodes(blackListNodes);
+                        failed = true;
+                        retryCount++;
+                    } else {
+                        throw e1;
+                    }
+                }
+            } while (failed && retryCount < maxRetryCount);
             LOG.info("job finished");
         } catch (Exception e) {
             throw new HyracksException(e);
         }
     }
 
+    private boolean compatible(PregelixJob lastJob, PregelixJob currentJob) {
+        Class lastVertexIdClass = BspUtils.getVertexIndexClass(lastJob.getConfiguration());
+        Class lastVertexValueClass = BspUtils.getVertexValueClass(lastJob.getConfiguration());
+        Class lastEdgeValueClass = BspUtils.getEdgeValueClass(lastJob.getConfiguration());
+        Path lastOutputPath = FileOutputFormat.getOutputPath(lastJob);
+
+        Class currentVertexIdClass = BspUtils.getVertexIndexClass(currentJob.getConfiguration());
+        Class currentVertexValueClass = BspUtils.getVertexValueClass(currentJob.getConfiguration());
+        Class currentEdegeValueClass = BspUtils.getEdgeValueClass(currentJob.getConfiguration());
+        Path[] currentInputPaths = FileInputFormat.getInputPaths(currentJob);
+
+        return lastVertexIdClass.equals(currentVertexIdClass)
+                && lastVertexValueClass.equals(currentVertexValueClass)
+                && lastEdgeValueClass.equals(currentEdegeValueClass)
+                && (currentInputPaths.length == 0 || (currentInputPaths.length == 1 && lastOutputPath
+                        .equals(currentInputPaths[0])));
+    }
+
+    private JobGen selectJobGen(Plan planChoice, PregelixJob currentJob) {
+        JobGen jobGen;
+        switch (planChoice) {
+            case INNER_JOIN:
+                jobGen = new JobGenInnerJoin(currentJob);
+                break;
+            case OUTER_JOIN:
+                jobGen = new JobGenOuterJoin(currentJob);
+                break;
+            case OUTER_JOIN_SORT:
+                jobGen = new JobGenOuterJoinSort(currentJob);
+                break;
+            case OUTER_JOIN_SINGLE_SORT:
+                jobGen = new JobGenOuterJoinSingleSort(currentJob);
+                break;
+            default:
+                jobGen = new JobGenInnerJoin(currentJob);
+        }
+        return jobGen;
+    }
+
+    private long loadData(PregelixJob currentJob, JobGen jobGen, DeploymentId deploymentId) throws IOException,
+            Exception {
+        long start;
+        long end;
+        long time;
+        start = System.currentTimeMillis();
+        FileSystem dfs = FileSystem.get(currentJob.getConfiguration());
+        Path outputPath = FileOutputFormat.getOutputPath(currentJob);
+        if (outputPath != null) {
+            dfs.delete(outputPath, true);
+        }
+        runCreate(deploymentId, jobGen);
+        runDataLoad(deploymentId, jobGen);
+        end = System.currentTimeMillis();
+        time = end - start;
+        LOG.info("data loading finished " + time + "ms");
+        return time;
+    }
+
+    private void finishJobs(JobGen jobGen, DeploymentId deploymentId) throws Exception {
+        long start;
+        long end;
+        long time;
+        start = System.currentTimeMillis();
+        runHDFSWRite(deploymentId, jobGen);
+        runCleanup(deploymentId, jobGen);
+        end = System.currentTimeMillis();
+        time = end - start;
+        LOG.info("result writing finished " + time + "ms");
+    }
+
+    private DeploymentId prepareJobs(String ipAddress, int port) throws Exception {
+        if (hcc == null) {
+            hcc = new HyracksConnection(ipAddress, port);
+        }
+        URLClassLoader classLoader = (URLClassLoader) exampleClass.getClassLoader();
+        List<File> jars = new ArrayList<File>();
+        URL[] urls = classLoader.getURLs();
+        for (URL url : urls)
+            if (url.toString().endsWith(".jar"))
+                jars.add(new File(url.getPath()));
+        DeploymentId deploymentId = installApplication(jars);
+        return deploymentId;
+    }
+
+    private void addHadoopConfiguration(PregelixJob job, String ipAddress, int port, boolean loadClusterConfig)
+            throws HyracksException {
+        URL hadoopCore = job.getClass().getClassLoader().getResource("core-site.xml");
+        if (hadoopCore != null) {
+            job.getConfiguration().addResource(hadoopCore);
+        }
+        URL hadoopMapRed = job.getClass().getClassLoader().getResource("mapred-site.xml");
+        if (hadoopMapRed != null) {
+            job.getConfiguration().addResource(hadoopMapRed);
+        }
+        URL hadoopHdfs = job.getClass().getClassLoader().getResource("hdfs-site.xml");
+        if (hadoopHdfs != null) {
+            job.getConfiguration().addResource(hadoopHdfs);
+        }
+        if (loadClusterConfig) {
+            ClusterConfig.loadClusterConfig(ipAddress, port);
+        }
+    }
+
+    private void runLoopBody(DeploymentId deploymentId, PregelixJob job, JobGen jobGen, int currentJobIndex,
+            IntWritable snapshotJobIndex, IntWritable snapshotSuperstep, ICheckpointHook ckpHook, boolean doRecovery)
+            throws Exception {
+        if (doRecovery) {
+            /** reload the checkpoint */
+            if (snapshotSuperstep.get() > 0) {
+                runClearState(deploymentId, jobGen);
+                runLoadCheckpoint(deploymentId, jobGen, snapshotSuperstep.get());
+            } else {
+                runClearState(deploymentId, jobGen);
+                loadData(job, jobGen, deploymentId);
+            }
+        }
+        int i = doRecovery ? snapshotSuperstep.get() + 1 : 1;
+        int ckpInterval = BspUtils.getCheckpointingInterval(job.getConfiguration());
+        boolean terminate = false;
+        long start, end, time;
+        do {
+            start = System.currentTimeMillis();
+            runLoopBodyIteration(deploymentId, jobGen, i);
+            end = System.currentTimeMillis();
+            time = end - start;
+            LOG.info(job + ": iteration " + i + " finished " + time + "ms");
+            terminate = IterationUtils.readTerminationState(job.getConfiguration(), jobGen.getJobId())
+                    || IterationUtils.readForceTerminationState(job.getConfiguration(), jobGen.getJobId());
+            if (ckpHook.checkpoint(i) || (ckpInterval > 0 && i % ckpInterval == 0)) {
+                runCheckpoint(deploymentId, jobGen, i);
+                snapshotJobIndex.set(currentJobIndex);
+                snapshotSuperstep.set(i);
+            }
+            i++;
+        } while (!terminate);
+    }
+
+    private void runCheckpoint(DeploymentId deploymentId, JobGen jobGen, int lastSuccessfulIteration) throws Exception {
+        try {
+            JobSpecification[] ckpJobs = jobGen.generateCheckpointing(lastSuccessfulIteration);
+            runJobArray(deploymentId, ckpJobs);
+        } catch (Exception e) {
+            throw e;
+        }
+    }
+
+    private void runLoadCheckpoint(DeploymentId deploymentId, JobGen jobGen, int checkPointedIteration)
+            throws Exception {
+        try {
+            JobSpecification[] ckpJobs = jobGen.generateLoadingCheckpoint(checkPointedIteration);
+            runJobArray(deploymentId, ckpJobs);
+        } catch (Exception e) {
+            throw e;
+        }
+    }
+
     private void runCreate(DeploymentId deploymentId, JobGen jobGen) throws Exception {
         try {
             JobSpecification treeCreateSpec = jobGen.generateCreatingJob();
@@ -196,6 +362,15 @@
         }
     }
 
+    private void runClearState(DeploymentId deploymentId, JobGen jobGen) throws Exception {
+        try {
+            JobSpecification clear = jobGen.generateClearState();
+            execute(deploymentId, clear);
+        } catch (Exception e) {
+            throw e;
+        }
+    }
+
     private void runJobArray(DeploymentId deploymentId, JobSpecification[] jobs) throws Exception {
         for (JobSpecification job : jobs) {
             execute(deploymentId, job);
@@ -204,6 +379,7 @@
 
     private void execute(DeploymentId deploymentId, JobSpecification job) throws Exception {
         job.setUseConnectorPolicyForScheduling(false);
+        job.setMaxReattempts(0);
         JobId jobId = hcc.startJob(deploymentId, job,
                 profiling ? EnumSet.of(JobFlag.PROFILE_RUNTIME) : EnumSet.noneOf(JobFlag.class));
         hcc.waitForCompletion(jobId);
diff --git a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGen.java b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGen.java
index 478ac07..4863378 100644
--- a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGen.java
+++ b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGen.java
@@ -15,8 +15,14 @@
 
 package edu.uci.ics.pregelix.core.jobgen;
 
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.DataInput;
+import java.io.DataInputStream;
 import java.io.DataOutput;
+import java.io.DataOutputStream;
 import java.io.File;
+import java.io.IOException;
 import java.lang.reflect.Type;
 import java.util.ArrayList;
 import java.util.List;
@@ -24,10 +30,18 @@
 import java.util.logging.Logger;
 
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.io.NullWritable;
 import org.apache.hadoop.io.Writable;
 import org.apache.hadoop.io.WritableComparable;
 import org.apache.hadoop.io.WritableComparator;
+import org.apache.hadoop.mapreduce.InputFormat;
 import org.apache.hadoop.mapreduce.InputSplit;
+import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
+import org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat;
+import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
+import org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat;
 
 import edu.uci.ics.hyracks.api.constraints.PartitionConstraintHelper;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
@@ -50,6 +64,7 @@
 import edu.uci.ics.hyracks.dataflow.std.file.IFileSplitProvider;
 import edu.uci.ics.hyracks.dataflow.std.misc.ConstantTupleSourceOperatorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.sort.ExternalSortOperatorDescriptor;
+import edu.uci.ics.hyracks.hdfs2.dataflow.HDFSReadOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.btree.dataflow.BTreeDataflowHelperFactory;
 import edu.uci.ics.hyracks.storage.am.btree.dataflow.BTreeSearchOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexLifecycleManagerProvider;
@@ -67,9 +82,12 @@
 import edu.uci.ics.hyracks.storage.common.file.TransientLocalResourceFactoryProvider;
 import edu.uci.ics.pregelix.api.graph.GlobalAggregator;
 import edu.uci.ics.pregelix.api.graph.MessageCombiner;
+import edu.uci.ics.pregelix.api.graph.MsgList;
 import edu.uci.ics.pregelix.api.graph.Vertex;
 import edu.uci.ics.pregelix.api.graph.VertexPartitioner;
 import edu.uci.ics.pregelix.api.io.VertexInputFormat;
+import edu.uci.ics.pregelix.api.io.internal.InternalVertexInputFormat;
+import edu.uci.ics.pregelix.api.io.internal.InternalVertexOutputFormat;
 import edu.uci.ics.pregelix.api.job.PregelixJob;
 import edu.uci.ics.pregelix.api.util.BspUtils;
 import edu.uci.ics.pregelix.api.util.ReflectionUtils;
@@ -79,15 +97,24 @@
 import edu.uci.ics.pregelix.core.jobgen.clusterconfig.ClusterConfig;
 import edu.uci.ics.pregelix.core.runtime.touchpoint.WritableComparingBinaryComparatorFactory;
 import edu.uci.ics.pregelix.core.util.DataflowUtils;
+import edu.uci.ics.pregelix.dataflow.ClearStateOperatorDescriptor;
+import edu.uci.ics.pregelix.dataflow.EmptySinkOperatorDescriptor;
+import edu.uci.ics.pregelix.dataflow.EmptyTupleSourceOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.HDFSFileWriteOperatorDescriptor;
+import edu.uci.ics.pregelix.dataflow.KeyValueParserFactory;
+import edu.uci.ics.pregelix.dataflow.MaterializingReadOperatorDescriptor;
+import edu.uci.ics.pregelix.dataflow.MaterializingWriteOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.VertexFileScanOperatorDescriptor;
+import edu.uci.ics.pregelix.dataflow.VertexFileWriteOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.VertexWriteOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.base.IConfigurationFactory;
+import edu.uci.ics.pregelix.dataflow.std.RuntimeHookOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.std.base.IRecordDescriptorFactory;
 import edu.uci.ics.pregelix.dataflow.std.base.IRuntimeHookFactory;
 import edu.uci.ics.pregelix.runtime.bootstrap.IndexLifeCycleManagerProvider;
 import edu.uci.ics.pregelix.runtime.bootstrap.StorageManagerInterface;
 import edu.uci.ics.pregelix.runtime.bootstrap.VirtualBufferCacheProvider;
+import edu.uci.ics.pregelix.runtime.touchpoint.RecoveryRuntimeHookFactory;
 import edu.uci.ics.pregelix.runtime.touchpoint.RuntimeHookFactory;
 import edu.uci.ics.pregelix.runtime.touchpoint.VertexIdPartitionComputerFactory;
 import edu.uci.ics.pregelix.runtime.touchpoint.VertexPartitionComputerFactory;
@@ -99,8 +126,8 @@
     protected static final float DEFAULT_BTREE_FILL_FACTOR = 1.00f;
     protected static final int tableSize = 10485767;
     protected static final String PRIMARY_INDEX = "primary";
-    protected final Configuration conf;
-    protected final PregelixJob giraphJob;
+    protected Configuration conf;
+    protected PregelixJob pregelixJob;
     protected IIndexLifecycleManagerProvider lcManagerProvider = IndexLifeCycleManagerProvider.INSTANCE;
     protected IStorageManagerInterface storageManagerInterface = StorageManagerInterface.INSTANCE;
     protected String jobId = new UUID(System.currentTimeMillis(), System.nanoTime()).toString();
@@ -111,13 +138,15 @@
     protected static final String SECONDARY_INDEX_EVEN = "secondary2";
 
     public JobGen(PregelixJob job) {
-        this.conf = job.getConfiguration();
-        this.giraphJob = job;
-        this.initJobConfiguration();
-        job.setJobId(jobId);
+        init(job);
+    }
 
-        // set the frame size to be the one user specified if the user did
-        // specify.
+    private void init(PregelixJob job) {
+        conf = job.getConfiguration();
+        pregelixJob = job;
+        initJobConfiguration();
+        job.setJobId(jobId);
+        // set the frame size to be the one user specified if the user did specify.
         int specifiedFrameSize = BspUtils.getFrameSize(job.getConfiguration());
         if (specifiedFrameSize > 0) {
             frameSize = specifiedFrameSize;
@@ -128,6 +157,10 @@
         }
     }
 
+    public void reset(PregelixJob job) {
+        init(job);
+    }
+
     @SuppressWarnings({ "rawtypes", "unchecked" })
     private void initJobConfiguration() {
         Class vertexClass = conf.getClass(PregelixJob.VERTEX_CLASS, Vertex.class);
@@ -187,74 +220,6 @@
         return spec;
     }
 
-    @SuppressWarnings({ "rawtypes", "unchecked" })
-    @Override
-    public JobSpecification generateLoadingJob() throws HyracksException {
-        Class<? extends WritableComparable<?>> vertexIdClass = BspUtils.getVertexIndexClass(conf);
-        Class<? extends Writable> vertexClass = BspUtils.getVertexClass(conf);
-        JobSpecification spec = new JobSpecification();
-        IFileSplitProvider fileSplitProvider = ClusterConfig.getFileSplitProvider(jobId, PRIMARY_INDEX);
-
-        /**
-         * the graph file scan operator and use count constraint first, will use
-         * absolute constraint later
-         */
-        VertexInputFormat inputFormat = BspUtils.createVertexInputFormat(conf);
-        List<InputSplit> splits = new ArrayList<InputSplit>();
-        try {
-            splits = inputFormat.getSplits(giraphJob, fileSplitProvider.getFileSplits().length);
-            LOGGER.info("number of splits: " + splits.size());
-            for (InputSplit split : splits)
-                LOGGER.info(split.toString());
-        } catch (Exception e) {
-            throw new HyracksDataException(e);
-        }
-        RecordDescriptor recordDescriptor = DataflowUtils.getRecordDescriptorFromKeyValueClasses(
-                vertexIdClass.getName(), vertexClass.getName());
-        IConfigurationFactory confFactory = new ConfigurationFactory(conf);
-        String[] readSchedule = ClusterConfig.getHdfsScheduler().getLocationConstraints(splits);
-        VertexFileScanOperatorDescriptor scanner = new VertexFileScanOperatorDescriptor(spec, recordDescriptor, splits,
-                readSchedule, confFactory);
-        ClusterConfig.setLocationConstraint(spec, scanner);
-
-        /**
-         * construct sort operator
-         */
-        int[] sortFields = new int[1];
-        sortFields[0] = 0;
-        INormalizedKeyComputerFactory nkmFactory = JobGenUtil.getINormalizedKeyComputerFactory(conf);
-        IBinaryComparatorFactory[] comparatorFactories = new IBinaryComparatorFactory[1];
-        comparatorFactories[0] = new WritableComparingBinaryComparatorFactory(WritableComparator.get(vertexIdClass)
-                .getClass());
-        ExternalSortOperatorDescriptor sorter = new ExternalSortOperatorDescriptor(spec, maxFrameNumber, sortFields,
-                nkmFactory, comparatorFactories, recordDescriptor);
-        ClusterConfig.setLocationConstraint(spec, sorter);
-
-        /**
-         * construct tree bulk load operator
-         */
-        int[] fieldPermutation = new int[2];
-        fieldPermutation[0] = 0;
-        fieldPermutation[1] = 1;
-        ITypeTraits[] typeTraits = new ITypeTraits[2];
-        typeTraits[0] = new TypeTraits(false);
-        typeTraits[1] = new TypeTraits(false);
-        TreeIndexBulkLoadOperatorDescriptor btreeBulkLoad = new TreeIndexBulkLoadOperatorDescriptor(spec,
-                storageManagerInterface, lcManagerProvider, fileSplitProvider, typeTraits, comparatorFactories,
-                sortFields, fieldPermutation, DEFAULT_BTREE_FILL_FACTOR, false, 0, false,
-                getIndexDataflowHelperFactory(), NoOpOperationCallbackFactory.INSTANCE);
-        ClusterConfig.setLocationConstraint(spec, btreeBulkLoad);
-
-        /**
-         * connect operator descriptors
-         */
-        ITuplePartitionComputerFactory hashPartitionComputerFactory = getVertexPartitionComputerFactory();
-        spec.connect(new MToNPartitioningConnectorDescriptor(spec, hashPartitionComputerFactory), scanner, 0, sorter, 0);
-        spec.connect(new OneToOneConnectorDescriptor(spec), sorter, 0, btreeBulkLoad, 0);
-        spec.setFrameSize(frameSize);
-        return spec;
-    }
-
     @Override
     public JobSpecification generateJob(int iteration) throws HyracksException {
         if (iteration <= 0)
@@ -280,7 +245,7 @@
         VertexInputFormat inputFormat = BspUtils.createVertexInputFormat(conf);
         List<InputSplit> splits = new ArrayList<InputSplit>();
         try {
-            splits = inputFormat.getSplits(giraphJob, fileSplitProvider.getFileSplits().length);
+            splits = inputFormat.getSplits(pregelixJob, fileSplitProvider.getFileSplits().length);
         } catch (Exception e) {
             throw new HyracksDataException(e);
         }
@@ -398,8 +363,201 @@
         return spec;
     }
 
-    @SuppressWarnings({ "rawtypes", "unchecked" })
     public JobSpecification scanIndexWriteGraph() throws HyracksException {
+        JobSpecification spec = scanIndexWriteToHDFS(conf);
+        return spec;
+    }
+
+    @Override
+    public JobSpecification[] generateCheckpointing(int lastSuccessfulIteration) throws HyracksException {
+        try {
+            PregelixJob tmpJob = this.createCloneJob("Vertex checkpointing for job " + jobId, pregelixJob);
+            tmpJob.setVertexOutputFormatClass(InternalVertexOutputFormat.class);
+            FileOutputFormat.setOutputPath(tmpJob,
+                    new Path(BspUtils.getVertexCheckpointPath(conf, lastSuccessfulIteration)));
+            tmpJob.setOutputKeyClass(NullWritable.class);
+            tmpJob.setOutputValueClass(BspUtils.getVertexClass(tmpJob.getConfiguration()));
+            FileSystem dfs = FileSystem.get(tmpJob.getConfiguration());
+
+            dfs.delete(new Path(BspUtils.getVertexCheckpointPath(conf, lastSuccessfulIteration)), true);
+            JobSpecification vertexCkpSpec = scanIndexWriteToHDFS(tmpJob.getConfiguration());
+
+            dfs.delete(new Path(BspUtils.getMessageCheckpointPath(conf, lastSuccessfulIteration)), true);
+            JobSpecification[] stateCkpSpecs = generateStateCheckpointing(lastSuccessfulIteration);
+            JobSpecification[] specs = new JobSpecification[1 + stateCkpSpecs.length];
+
+            specs[0] = vertexCkpSpec;
+            for (int i = 1; i < specs.length; i++) {
+                specs[i] = stateCkpSpecs[i - 1];
+            }
+            return specs;
+        } catch (Exception e) {
+            throw new HyracksException(e);
+        }
+    }
+
+    @Override
+    public JobSpecification generateLoadingJob() throws HyracksException {
+        JobSpecification spec = loadHDFSData(pregelixJob);
+        return spec;
+    }
+
+    public void clearCheckpoints() throws IOException {
+        FileSystem dfs = FileSystem.get(conf);
+        // clear the checkpoint directory
+        dfs.delete(new Path("/tmp/ckpoint/" + jobId), true);
+    }
+
+    @Override
+    public JobSpecification[] generateLoadingCheckpoint(int lastCheckpointedIteration) throws HyracksException {
+        try {
+            PregelixJob tmpJob = this.createCloneJob("Vertex checkpoint loading for job " + jobId, pregelixJob);
+            tmpJob.setVertexInputFormatClass(InternalVertexInputFormat.class);
+            FileInputFormat.setInputPaths(tmpJob,
+                    new Path(BspUtils.getVertexCheckpointPath(conf, lastCheckpointedIteration)));
+            JobSpecification[] cleanVertices = generateCleanup();
+            JobSpecification createIndex = generateCreatingJob();
+            JobSpecification vertexLoadSpec = loadHDFSData(tmpJob);
+            JobSpecification[] stateLoadSpecs = generateStateCheckpointLoading(lastCheckpointedIteration, tmpJob);
+            JobSpecification[] specs = new JobSpecification[cleanVertices.length + 2 + stateLoadSpecs.length];
+
+            int i = 0;
+            for (; i < cleanVertices.length; i++) {
+                specs[i] = cleanVertices[i];
+            }
+            specs[i++] = createIndex;
+            specs[i++] = vertexLoadSpec;
+            for (; i < specs.length; i++) {
+                specs[i] = stateLoadSpecs[i - cleanVertices.length - 2];
+            }
+            return specs;
+        } catch (Exception e) {
+            throw new HyracksException(e);
+        }
+    }
+
+    /***
+     * generate a "clear state" job
+     */
+    public JobSpecification generateClearState() throws HyracksException {
+        JobSpecification spec = new JobSpecification();
+        ClearStateOperatorDescriptor clearState = new ClearStateOperatorDescriptor(spec, jobId);
+        ClusterConfig.setLocationConstraint(spec, clearState);
+        spec.addRoot(clearState);
+        return spec;
+    }
+
+    /***
+     * drop the sindex
+     * 
+     * @return JobSpecification
+     * @throws HyracksException
+     */
+    protected JobSpecification dropIndex(String indexName) throws HyracksException {
+        JobSpecification spec = new JobSpecification();
+
+        IFileSplitProvider fileSplitProvider = ClusterConfig.getFileSplitProvider(jobId, indexName);
+        IndexDropOperatorDescriptor drop = new IndexDropOperatorDescriptor(spec, storageManagerInterface,
+                lcManagerProvider, fileSplitProvider, getIndexDataflowHelperFactory());
+
+        ClusterConfig.setLocationConstraint(spec, drop);
+        spec.addRoot(drop);
+        spec.setFrameSize(frameSize);
+        return spec;
+    }
+
+    @SuppressWarnings({ "unchecked", "rawtypes" })
+    protected ITuplePartitionComputerFactory getVertexPartitionComputerFactory() {
+        IConfigurationFactory confFactory = new ConfigurationFactory(conf);
+        Class<? extends VertexPartitioner> partitionerClazz = BspUtils.getVertexPartitionerClass(conf);
+        if (partitionerClazz != null) {
+            return new VertexPartitionComputerFactory(confFactory);
+        } else {
+            return new VertexIdPartitionComputerFactory(new WritableSerializerDeserializerFactory(
+                    BspUtils.getVertexIndexClass(conf)));
+        }
+    }
+
+    protected IIndexDataflowHelperFactory getIndexDataflowHelperFactory() {
+        if (BspUtils.useLSM(conf)) {
+            return new LSMBTreeDataflowHelperFactory(new VirtualBufferCacheProvider(), new ConstantMergePolicyProvider(
+                    3), NoOpOperationTrackerProvider.INSTANCE, SynchronousSchedulerProvider.INSTANCE,
+                    NoOpIOOperationCallback.INSTANCE, 0.01);
+        } else {
+            return new BTreeDataflowHelperFactory();
+        }
+    }
+
+    @SuppressWarnings({ "rawtypes", "unchecked" })
+    private JobSpecification loadHDFSData(PregelixJob job) throws HyracksException, HyracksDataException {
+        Configuration conf = job.getConfiguration();
+        Class<? extends WritableComparable<?>> vertexIdClass = BspUtils.getVertexIndexClass(conf);
+        Class<? extends Writable> vertexClass = BspUtils.getVertexClass(conf);
+        JobSpecification spec = new JobSpecification();
+        IFileSplitProvider fileSplitProvider = ClusterConfig.getFileSplitProvider(jobId, PRIMARY_INDEX);
+
+        /**
+         * the graph file scan operator and use count constraint first, will use
+         * absolute constraint later
+         */
+        VertexInputFormat inputFormat = BspUtils.createVertexInputFormat(conf);
+        List<InputSplit> splits = new ArrayList<InputSplit>();
+        try {
+            splits = inputFormat.getSplits(job, fileSplitProvider.getFileSplits().length);
+            LOGGER.info("number of splits: " + splits.size());
+            for (InputSplit split : splits)
+                LOGGER.info(split.toString());
+        } catch (Exception e) {
+            throw new HyracksDataException(e);
+        }
+        RecordDescriptor recordDescriptor = DataflowUtils.getRecordDescriptorFromKeyValueClasses(
+                vertexIdClass.getName(), vertexClass.getName());
+        IConfigurationFactory confFactory = new ConfigurationFactory(conf);
+        String[] readSchedule = ClusterConfig.getHdfsScheduler().getLocationConstraints(splits);
+        VertexFileScanOperatorDescriptor scanner = new VertexFileScanOperatorDescriptor(spec, recordDescriptor, splits,
+                readSchedule, confFactory);
+        ClusterConfig.setLocationConstraint(spec, scanner);
+
+        /**
+         * construct sort operator
+         */
+        int[] sortFields = new int[1];
+        sortFields[0] = 0;
+        INormalizedKeyComputerFactory nkmFactory = JobGenUtil.getINormalizedKeyComputerFactory(conf);
+        IBinaryComparatorFactory[] comparatorFactories = new IBinaryComparatorFactory[1];
+        comparatorFactories[0] = new WritableComparingBinaryComparatorFactory(WritableComparator.get(vertexIdClass)
+                .getClass());
+        ExternalSortOperatorDescriptor sorter = new ExternalSortOperatorDescriptor(spec, maxFrameNumber, sortFields,
+                nkmFactory, comparatorFactories, recordDescriptor);
+        ClusterConfig.setLocationConstraint(spec, sorter);
+
+        /**
+         * construct tree bulk load operator
+         */
+        int[] fieldPermutation = new int[2];
+        fieldPermutation[0] = 0;
+        fieldPermutation[1] = 1;
+        ITypeTraits[] typeTraits = new ITypeTraits[2];
+        typeTraits[0] = new TypeTraits(false);
+        typeTraits[1] = new TypeTraits(false);
+        TreeIndexBulkLoadOperatorDescriptor btreeBulkLoad = new TreeIndexBulkLoadOperatorDescriptor(spec,
+                storageManagerInterface, lcManagerProvider, fileSplitProvider, typeTraits, comparatorFactories,
+                sortFields, fieldPermutation, DEFAULT_BTREE_FILL_FACTOR, true, 0, false,
+                getIndexDataflowHelperFactory(), NoOpOperationCallbackFactory.INSTANCE);
+        ClusterConfig.setLocationConstraint(spec, btreeBulkLoad);
+
+        /**
+         * connect operator descriptors
+         */
+        ITuplePartitionComputerFactory hashPartitionComputerFactory = getVertexPartitionComputerFactory();
+        spec.connect(new MToNPartitioningConnectorDescriptor(spec, hashPartitionComputerFactory), scanner, 0, sorter, 0);
+        spec.connect(new OneToOneConnectorDescriptor(spec), sorter, 0, btreeBulkLoad, 0);
+        spec.setFrameSize(frameSize);
+        return spec;
+    }
+
+    @SuppressWarnings({ "rawtypes", "unchecked" })
+    private JobSpecification scanIndexWriteToHDFS(Configuration conf) throws HyracksDataException, HyracksException {
         Class<? extends WritableComparable<?>> vertexIdClass = BspUtils.getVertexIndexClass(conf);
         Class<? extends Writable> vertexClass = BspUtils.getVertexClass(conf);
         JobSpecification spec = new JobSpecification();
@@ -444,7 +602,8 @@
          */
         IRecordDescriptorFactory inputRdFactory = DataflowUtils.getWritableRecordDescriptorFactoryFromWritableClasses(
                 vertexIdClass.getName(), vertexClass.getName());
-        HDFSFileWriteOperatorDescriptor writer = new HDFSFileWriteOperatorDescriptor(spec, confFactory, inputRdFactory);
+        VertexFileWriteOperatorDescriptor writer = new VertexFileWriteOperatorDescriptor(spec, confFactory,
+                inputRdFactory);
         ClusterConfig.setLocationConstraint(spec, writer);
 
         /**
@@ -456,45 +615,137 @@
         return spec;
     }
 
-    /***
-     * drop the sindex
-     * 
-     * @return JobSpecification
-     * @throws HyracksException
-     */
-    protected JobSpecification dropIndex(String indexName) throws HyracksException {
-        JobSpecification spec = new JobSpecification();
-
-        IFileSplitProvider fileSplitProvider = ClusterConfig.getFileSplitProvider(jobId, indexName);
-        IndexDropOperatorDescriptor drop = new IndexDropOperatorDescriptor(spec, storageManagerInterface,
-                lcManagerProvider, fileSplitProvider, getIndexDataflowHelperFactory());
-
-        ClusterConfig.setLocationConstraint(spec, drop);
-        spec.addRoot(drop);
-        spec.setFrameSize(frameSize);
-        return spec;
-    }
-
-    @SuppressWarnings({ "unchecked", "rawtypes" })
-    protected ITuplePartitionComputerFactory getVertexPartitionComputerFactory() {
-        IConfigurationFactory confFactory = new ConfigurationFactory(conf);
-        Class<? extends VertexPartitioner> partitionerClazz = BspUtils.getVertexPartitionerClass(conf);
-        if (partitionerClazz != null) {
-            return new VertexPartitionComputerFactory(confFactory);
-        } else {
-            return new VertexIdPartitionComputerFactory(new WritableSerializerDeserializerFactory(
-                    BspUtils.getVertexIndexClass(conf)));
+    protected PregelixJob createCloneJob(String newJobName, PregelixJob oldJob) throws HyracksException {
+        try {
+            ByteArrayOutputStream bos = new ByteArrayOutputStream();
+            DataOutput dos = new DataOutputStream(bos);
+            oldJob.getConfiguration().write(dos);
+            PregelixJob newJob = new PregelixJob(newJobName);
+            DataInput dis = new DataInputStream(new ByteArrayInputStream(bos.toByteArray()));
+            newJob.getConfiguration().readFields(dis);
+            return newJob;
+        } catch (IOException e) {
+            throw new HyracksException(e);
         }
     }
 
-    protected IIndexDataflowHelperFactory getIndexDataflowHelperFactory() {
-        if (BspUtils.useLSM(conf)) {
-            return new LSMBTreeDataflowHelperFactory(new VirtualBufferCacheProvider(), new ConstantMergePolicyProvider(
-                    3), NoOpOperationTrackerProvider.INSTANCE, SynchronousSchedulerProvider.INSTANCE,
-                    NoOpIOOperationCallback.INSTANCE, 0.01);
-        } else {
-            return new BTreeDataflowHelperFactory();
-       }
+    /** generate plan specific state checkpointing */
+    protected JobSpecification[] generateStateCheckpointing(int lastSuccessfulIteration) throws HyracksException {
+        Class<? extends WritableComparable<?>> vertexIdClass = BspUtils.getVertexIndexClass(conf);
+        JobSpecification spec = new JobSpecification();
+
+        /**
+         * source aggregate
+         */
+        RecordDescriptor rdFinal = DataflowUtils.getRecordDescriptorFromKeyValueClasses(vertexIdClass.getName(),
+                MsgList.class.getName());
+
+        /**
+         * construct empty tuple operator
+         */
+        EmptyTupleSourceOperatorDescriptor emptyTupleSource = new EmptyTupleSourceOperatorDescriptor(spec);
+        ClusterConfig.setLocationConstraint(spec, emptyTupleSource);
+
+        /**
+         * construct the materializing write operator
+         */
+        MaterializingReadOperatorDescriptor materializeRead = new MaterializingReadOperatorDescriptor(spec, rdFinal,
+                false);
+        ClusterConfig.setLocationConstraint(spec, materializeRead);
+
+        String checkpointPath = BspUtils.getMessageCheckpointPath(conf, lastSuccessfulIteration);;
+        PregelixJob tmpJob = createCloneJob("State checkpointing for job " + jobId, pregelixJob);
+        tmpJob.setOutputFormatClass(SequenceFileOutputFormat.class);
+        FileOutputFormat.setOutputPath(tmpJob, new Path(checkpointPath));
+        tmpJob.setOutputKeyClass(vertexIdClass);
+        tmpJob.setOutputValueClass(MsgList.class);
+
+        IRecordDescriptorFactory inputRdFactory = DataflowUtils.getWritableRecordDescriptorFactoryFromWritableClasses(
+                vertexIdClass.getName(), MsgList.class.getName());
+        HDFSFileWriteOperatorDescriptor hdfsWriter = new HDFSFileWriteOperatorDescriptor(spec, tmpJob, inputRdFactory);
+        ClusterConfig.setLocationConstraint(spec, hdfsWriter);
+
+        spec.connect(new OneToOneConnectorDescriptor(spec), emptyTupleSource, 0, materializeRead, 0);
+        spec.connect(new OneToOneConnectorDescriptor(spec), materializeRead, 0, hdfsWriter, 0);
+        spec.setFrameSize(frameSize);
+        return new JobSpecification[] { spec };
+    }
+
+    /** load plan specific state checkpoints */
+    @SuppressWarnings({ "unchecked", "rawtypes" })
+    protected JobSpecification[] generateStateCheckpointLoading(int lastCheckpointedIteration, PregelixJob job)
+            throws HyracksException {
+        String checkpointPath = BspUtils.getMessageCheckpointPath(job.getConfiguration(), lastCheckpointedIteration);
+        PregelixJob tmpJob = createCloneJob("State checkpoint loading for job " + jobId, job);
+        tmpJob.setInputFormatClass(SequenceFileInputFormat.class);
+        try {
+            FileInputFormat.setInputPaths(tmpJob, checkpointPath);
+        } catch (IOException e) {
+            throw new HyracksException(e);
+        }
+        Configuration conf = tmpJob.getConfiguration();
+        Class vertexIdClass = BspUtils.getVertexIndexClass(conf);
+        JobSpecification spec = new JobSpecification();
+
+        /***
+         * HDFS read operator
+         */
+        List<InputSplit> splits = new ArrayList<InputSplit>();
+        try {
+            InputFormat inputFormat = org.apache.hadoop.util.ReflectionUtils.newInstance(job.getInputFormatClass(),
+                    job.getConfiguration());
+            splits = inputFormat.getSplits(tmpJob);
+            LOGGER.info("number of splits: " + splits.size());
+            for (InputSplit split : splits)
+                LOGGER.info(split.toString());
+        } catch (Exception e) {
+            throw new HyracksDataException(e);
+        }
+        RecordDescriptor recordDescriptor = DataflowUtils.getRecordDescriptorFromKeyValueClasses(
+                vertexIdClass.getName(), MsgList.class.getName());
+        String[] readSchedule = ClusterConfig.getHdfsScheduler().getLocationConstraints(splits);
+        HDFSReadOperatorDescriptor scanner = new HDFSReadOperatorDescriptor(spec, recordDescriptor, tmpJob, splits,
+                readSchedule, new KeyValueParserFactory());
+        ClusterConfig.setLocationConstraint(spec, scanner);
+
+        /** construct the sort operator to sort message states */
+        int[] keyFields = new int[] { 0 };
+        INormalizedKeyComputerFactory nkmFactory = JobGenUtil.getINormalizedKeyComputerFactory(conf);
+        IBinaryComparatorFactory[] sortCmpFactories = new IBinaryComparatorFactory[1];
+        sortCmpFactories[0] = JobGenUtil.getIBinaryComparatorFactory(lastCheckpointedIteration,
+                WritableComparator.get(vertexIdClass).getClass());
+        ExternalSortOperatorDescriptor sort = new ExternalSortOperatorDescriptor(spec, maxFrameNumber, keyFields,
+                nkmFactory, sortCmpFactories, recordDescriptor);
+        ClusterConfig.setLocationConstraint(spec, sort);
+
+        /**
+         * construct the materializing write operator
+         */
+        MaterializingWriteOperatorDescriptor materialize = new MaterializingWriteOperatorDescriptor(spec,
+                recordDescriptor);
+        ClusterConfig.setLocationConstraint(spec, materialize);
+
+        /** construct runtime hook */
+        RuntimeHookOperatorDescriptor postSuperStep = new RuntimeHookOperatorDescriptor(spec,
+                new RecoveryRuntimeHookFactory(jobId, lastCheckpointedIteration, new ConfigurationFactory(
+                        pregelixJob.getConfiguration())));
+        ClusterConfig.setLocationConstraint(spec, postSuperStep);
+
+        /** construct empty sink operator */
+        EmptySinkOperatorDescriptor emptySink = new EmptySinkOperatorDescriptor(spec);
+        ClusterConfig.setLocationConstraint(spec, emptySink);
+
+        /**
+         * connect operator descriptors
+         */
+        ITuplePartitionComputerFactory hashPartitionComputerFactory = getVertexPartitionComputerFactory();
+        spec.connect(new MToNPartitioningConnectorDescriptor(spec, hashPartitionComputerFactory), scanner, 0,
+                sort, 0);
+        spec.connect(new OneToOneConnectorDescriptor(spec), sort, 0, materialize, 0);
+        spec.connect(new OneToOneConnectorDescriptor(spec), materialize, 0, postSuperStep, 0);
+        spec.connect(new OneToOneConnectorDescriptor(spec), postSuperStep, 0, emptySink, 0);
+        spec.setFrameSize(frameSize);
+        return new JobSpecification[] { spec };
     }
 
     /** generate non-first iteration job */
diff --git a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGenInnerJoin.java b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGenInnerJoin.java
index db6c2c8..9389f62 100644
--- a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGenInnerJoin.java
+++ b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGenInnerJoin.java
@@ -15,26 +15,44 @@
 
 package edu.uci.ics.pregelix.core.jobgen;
 
+import java.io.DataOutput;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.logging.Logger;
+
+import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.io.VLongWritable;
 import org.apache.hadoop.io.Writable;
 import org.apache.hadoop.io.WritableComparable;
 import org.apache.hadoop.io.WritableComparator;
+import org.apache.hadoop.mapreduce.InputFormat;
+import org.apache.hadoop.mapreduce.InputSplit;
+import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
+import org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat;
+import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
+import org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat;
 
 import edu.uci.ics.hyracks.api.constraints.PartitionConstraintHelper;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.INormalizedKeyComputerFactory;
+import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
 import edu.uci.ics.hyracks.api.dataflow.value.ITuplePartitionComputerFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 import edu.uci.ics.hyracks.api.job.JobSpecification;
+import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
+import edu.uci.ics.hyracks.dataflow.common.data.marshalling.UTF8StringSerializerDeserializer;
 import edu.uci.ics.hyracks.dataflow.std.connectors.MToNPartitioningConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.connectors.MToNPartitioningMergingConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.connectors.OneToOneConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.file.IFileSplitProvider;
-import edu.uci.ics.hyracks.dataflow.std.group.IAggregatorDescriptorFactory;
-import edu.uci.ics.hyracks.dataflow.std.group.preclustered.PreclusteredGroupOperatorDescriptor;
+import edu.uci.ics.hyracks.dataflow.std.misc.ConstantTupleSourceOperatorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.sort.ExternalSortOperatorDescriptor;
+import edu.uci.ics.hyracks.hdfs2.dataflow.HDFSReadOperatorDescriptor;
+import edu.uci.ics.hyracks.storage.am.btree.dataflow.BTreeSearchOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.TreeIndexInsertUpdateDeleteOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallbackFactory;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
@@ -50,10 +68,14 @@
 import edu.uci.ics.pregelix.dataflow.EmptySinkOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.EmptyTupleSourceOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.FinalAggregateOperatorDescriptor;
+import edu.uci.ics.pregelix.dataflow.HDFSFileWriteOperatorDescriptor;
+import edu.uci.ics.pregelix.dataflow.KeyValueParserFactory;
 import edu.uci.ics.pregelix.dataflow.MaterializingReadOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.MaterializingWriteOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.TerminationStateWriterOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.base.IConfigurationFactory;
+import edu.uci.ics.pregelix.dataflow.group.ClusteredGroupOperatorDescriptor;
+import edu.uci.ics.pregelix.dataflow.group.IClusteredAggregatorDescriptorFactory;
 import edu.uci.ics.pregelix.dataflow.std.IndexNestedLoopJoinFunctionUpdateOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.std.IndexNestedLoopJoinOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.std.RuntimeHookOperatorDescriptor;
@@ -69,6 +91,7 @@
 import edu.uci.ics.pregelix.runtime.touchpoint.RuntimeHookFactory;
 
 public class JobGenInnerJoin extends JobGen {
+    private static final Logger LOGGER = Logger.getLogger(JobGen.class.getName());
 
     public JobGenInnerJoin(PregelixJob job) {
         super(job);
@@ -178,18 +201,18 @@
         /**
          * construct local pre-clustered group-by operator
          */
-        IAggregatorDescriptorFactory aggregatorFactory = DataflowUtils.getAccumulatingAggregatorFactory(conf, false,
-                false);
-        PreclusteredGroupOperatorDescriptor localGby = new PreclusteredGroupOperatorDescriptor(spec, keyFields,
+        IClusteredAggregatorDescriptorFactory aggregatorFactory = DataflowUtils.getAccumulatingAggregatorFactory(conf,
+                false, false);
+        ClusteredGroupOperatorDescriptor localGby = new ClusteredGroupOperatorDescriptor(spec, keyFields,
                 sortCmpFactories, aggregatorFactory, rdUnnestedMessage);
         ClusterConfig.setLocationConstraint(spec, localGby);
 
         /**
          * construct global group-by operator
          */
-        IAggregatorDescriptorFactory aggregatorFactoryFinal = DataflowUtils.getAccumulatingAggregatorFactory(conf,
-                true, true);
-        PreclusteredGroupOperatorDescriptor globalGby = new PreclusteredGroupOperatorDescriptor(spec, keyFields,
+        IClusteredAggregatorDescriptorFactory aggregatorFactoryFinal = DataflowUtils.getAccumulatingAggregatorFactory(
+                conf, true, true);
+        ClusteredGroupOperatorDescriptor globalGby = new ClusteredGroupOperatorDescriptor(spec, keyFields,
                 sortCmpFactories, aggregatorFactoryFinal, rdFinal);
         ClusterConfig.setLocationConstraint(spec, globalGby);
 
@@ -318,7 +341,8 @@
         /**
          * construct the materializing write operator
          */
-        MaterializingReadOperatorDescriptor materializeRead = new MaterializingReadOperatorDescriptor(spec, rdFinal);
+        MaterializingReadOperatorDescriptor materializeRead = new MaterializingReadOperatorDescriptor(spec, rdFinal,
+                true);
         ClusterConfig.setLocationConstraint(spec, materializeRead);
 
         /**
@@ -383,18 +407,18 @@
         /**
          * construct local pre-clustered group-by operator
          */
-        IAggregatorDescriptorFactory aggregatorFactory = DataflowUtils.getAccumulatingAggregatorFactory(conf, false,
-                false);
-        PreclusteredGroupOperatorDescriptor localGby = new PreclusteredGroupOperatorDescriptor(spec, keyFields,
+        IClusteredAggregatorDescriptorFactory aggregatorFactory = DataflowUtils.getAccumulatingAggregatorFactory(conf,
+                false, false);
+        ClusteredGroupOperatorDescriptor localGby = new ClusteredGroupOperatorDescriptor(spec, keyFields,
                 sortCmpFactories, aggregatorFactory, rdUnnestedMessage);
         ClusterConfig.setLocationConstraint(spec, localGby);
 
         /**
          * construct global group-by operator
          */
-        IAggregatorDescriptorFactory aggregatorFactoryFinal = DataflowUtils.getAccumulatingAggregatorFactory(conf,
-                true, true);
-        PreclusteredGroupOperatorDescriptor globalGby = new PreclusteredGroupOperatorDescriptor(spec, keyFields,
+        IClusteredAggregatorDescriptorFactory aggregatorFactoryFinal = DataflowUtils.getAccumulatingAggregatorFactory(
+                conf, true, true);
+        ClusteredGroupOperatorDescriptor globalGby = new ClusteredGroupOperatorDescriptor(spec, keyFields,
                 sortCmpFactories, aggregatorFactoryFinal, rdFinal);
         ClusterConfig.setLocationConstraint(spec, globalGby);
 
@@ -496,6 +520,184 @@
         return spec;
     }
 
+    /** generate plan specific state checkpointing */
+    protected JobSpecification[] generateStateCheckpointing(int lastSuccessfulIteration) throws HyracksException {
+        JobSpecification[] msgCkpSpecs = super.generateStateCheckpointing(lastSuccessfulIteration);
+
+        /** generate secondary index checkpoint */
+        PregelixJob tmpJob = this.createCloneJob("Secondary index checkpointing for job " + jobId, pregelixJob);
+
+        JobSpecification secondaryBTreeCkp = generateSecondaryBTreeCheckpoint(lastSuccessfulIteration, tmpJob);
+
+        JobSpecification[] specs = new JobSpecification[msgCkpSpecs.length + 1];
+        for (int i = 0; i < msgCkpSpecs.length; i++) {
+            specs[i] = msgCkpSpecs[i];
+        }
+        specs[specs.length - 1] = secondaryBTreeCkp;
+        return specs;
+    }
+
+    /**
+     * generate plan specific checkpoint loading
+     */
+    @Override
+    protected JobSpecification[] generateStateCheckpointLoading(int lastSuccessfulIteration, PregelixJob job)
+            throws HyracksException {
+        /** generate message checkpoint load */
+        JobSpecification[] msgCkpSpecs = super.generateStateCheckpointLoading(lastSuccessfulIteration, job);
+
+        /** generate secondary index checkpoint load */
+        PregelixJob tmpJob = this.createCloneJob("Secondary index checkpoint loading for job " + jobId, pregelixJob);
+        tmpJob.setOutputFormatClass(SequenceFileOutputFormat.class);
+        JobSpecification secondaryBTreeCkpLoad = generateSecondaryBTreeCheckpointLoad(lastSuccessfulIteration, tmpJob);
+        JobSpecification[] specs = new JobSpecification[msgCkpSpecs.length + 1];
+        for (int i = 0; i < msgCkpSpecs.length; i++) {
+            specs[i] = msgCkpSpecs[i];
+        }
+        specs[specs.length - 1] = secondaryBTreeCkpLoad;
+        return specs;
+    }
+
+    @SuppressWarnings({ "unchecked", "rawtypes" })
+    private JobSpecification generateSecondaryBTreeCheckpointLoad(int lastSuccessfulIteration, PregelixJob job)
+            throws HyracksException {
+        Class<? extends WritableComparable<?>> vertexIdClass = BspUtils.getVertexIndexClass(job.getConfiguration());
+        JobSpecification spec = new JobSpecification();
+
+        String checkpointPath = BspUtils.getSecondaryIndexCheckpointPath(conf, lastSuccessfulIteration);
+        PregelixJob tmpJob = createCloneJob("State checkpoint loading for job " + jobId, job);
+        tmpJob.setInputFormatClass(SequenceFileInputFormat.class);
+        try {
+            FileInputFormat.setInputPaths(tmpJob, checkpointPath);
+        } catch (IOException e) {
+            throw new HyracksException(e);
+        }
+
+        /***
+         * HDFS read operator
+         */
+        List<InputSplit> splits = new ArrayList<InputSplit>();
+        try {
+            InputFormat inputFormat = org.apache.hadoop.util.ReflectionUtils.newInstance(job.getInputFormatClass(),
+                    job.getConfiguration());
+            splits = inputFormat.getSplits(tmpJob);
+            LOGGER.info("number of splits: " + splits.size());
+            for (InputSplit split : splits)
+                LOGGER.info(split.toString());
+        } catch (Exception e) {
+            throw new HyracksDataException(e);
+        }
+        RecordDescriptor recordDescriptor = DataflowUtils.getRecordDescriptorFromKeyValueClasses(
+                vertexIdClass.getName(), MsgList.class.getName());
+        String[] readSchedule = ClusterConfig.getHdfsScheduler().getLocationConstraints(splits);
+        HDFSReadOperatorDescriptor scanner = new HDFSReadOperatorDescriptor(spec, recordDescriptor, tmpJob, splits,
+                readSchedule, new KeyValueParserFactory());
+        ClusterConfig.setLocationConstraint(spec, scanner);
+
+        /** construct the sort operator to sort message states */
+        int[] keyFields = new int[] { 0 };
+        INormalizedKeyComputerFactory nkmFactory = JobGenUtil.getINormalizedKeyComputerFactory(conf);
+        IBinaryComparatorFactory[] sortCmpFactories = new IBinaryComparatorFactory[1];
+        sortCmpFactories[0] = JobGenUtil.getIBinaryComparatorFactory(lastSuccessfulIteration,
+                WritableComparator.get(vertexIdClass).getClass());
+        ExternalSortOperatorDescriptor sort = new ExternalSortOperatorDescriptor(spec, maxFrameNumber, keyFields,
+                nkmFactory, sortCmpFactories, recordDescriptor);
+        ClusterConfig.setLocationConstraint(spec, sort);
+
+        /**
+         * construct bulk-load index operator
+         */
+        ITypeTraits[] typeTraits = new ITypeTraits[2];
+        typeTraits[0] = new TypeTraits(false);
+        typeTraits[1] = new TypeTraits(false);
+        int fieldPermutation[] = new int[] { 0, 1 };
+        IBinaryComparatorFactory[] indexCmpFactories = new IBinaryComparatorFactory[1];
+        indexCmpFactories[0] = JobGenUtil.getIBinaryComparatorFactory(lastSuccessfulIteration + 1, WritableComparator
+                .get(vertexIdClass).getClass());
+        String writeFile = lastSuccessfulIteration % 2 == 0 ? SECONDARY_INDEX_EVEN : SECONDARY_INDEX_ODD;
+        IFileSplitProvider secondaryFileSplitProviderWrite = ClusterConfig.getFileSplitProvider(jobId, writeFile);
+        TreeIndexBulkReLoadOperatorDescriptor btreeBulkLoad = new TreeIndexBulkReLoadOperatorDescriptor(spec,
+                storageManagerInterface, lcManagerProvider, secondaryFileSplitProviderWrite, typeTraits,
+                indexCmpFactories, fieldPermutation, new int[] { 0 }, DEFAULT_BTREE_FILL_FACTOR,
+                getIndexDataflowHelperFactory());
+        ClusterConfig.setLocationConstraint(spec, btreeBulkLoad);
+
+        /**
+         * connect operator descriptors
+         */
+        ITuplePartitionComputerFactory hashPartitionComputerFactory = getVertexPartitionComputerFactory();
+        spec.connect(new MToNPartitioningConnectorDescriptor(spec, hashPartitionComputerFactory), scanner, 0, sort, 0);
+        spec.connect(new OneToOneConnectorDescriptor(spec), sort, 0, btreeBulkLoad, 0);
+        spec.setFrameSize(frameSize);
+
+        return spec;
+    }
+
+    @SuppressWarnings({ "rawtypes", "unchecked" })
+    private JobSpecification generateSecondaryBTreeCheckpoint(int lastSuccessfulIteration, PregelixJob job)
+            throws HyracksException {
+        job.setOutputFormatClass(SequenceFileOutputFormat.class);
+        String checkpointPath = BspUtils.getSecondaryIndexCheckpointPath(conf, lastSuccessfulIteration);
+        FileOutputFormat.setOutputPath(job, new Path(checkpointPath));
+        job.setOutputKeyClass(BspUtils.getVertexIndexClass(job.getConfiguration()));
+        job.setOutputValueClass(MsgList.class);
+
+        Class<? extends WritableComparable<?>> vertexIdClass = BspUtils.getVertexIndexClass(job.getConfiguration());
+        Class<? extends Writable> msgListClass = MsgList.class;
+        String readFile = lastSuccessfulIteration % 2 == 0 ? SECONDARY_INDEX_EVEN : SECONDARY_INDEX_ODD;
+        IFileSplitProvider secondaryFileSplitProviderRead = ClusterConfig.getFileSplitProvider(jobId, readFile);
+        JobSpecification spec = new JobSpecification();
+        /**
+         * construct empty tuple operator
+         */
+        ArrayTupleBuilder tb = new ArrayTupleBuilder(2);
+        DataOutput dos = tb.getDataOutput();
+        tb.reset();
+        UTF8StringSerializerDeserializer.INSTANCE.serialize("0", dos);
+        tb.addFieldEndOffset();
+        ISerializerDeserializer[] keyRecDescSers = { UTF8StringSerializerDeserializer.INSTANCE,
+                UTF8StringSerializerDeserializer.INSTANCE };
+        RecordDescriptor keyRecDesc = new RecordDescriptor(keyRecDescSers);
+        ConstantTupleSourceOperatorDescriptor emptyTupleSource = new ConstantTupleSourceOperatorDescriptor(spec,
+                keyRecDesc, tb.getFieldEndOffsets(), tb.getByteArray(), tb.getSize());
+        ClusterConfig.setLocationConstraint(spec, emptyTupleSource);
+
+        /**
+         * construct btree search operator
+         */
+        RecordDescriptor recordDescriptor = DataflowUtils.getRecordDescriptorFromKeyValueClasses(
+                vertexIdClass.getName(), msgListClass.getName());
+        IBinaryComparatorFactory[] comparatorFactories = new IBinaryComparatorFactory[1];
+        comparatorFactories[0] = new WritableComparingBinaryComparatorFactory(WritableComparator.get(vertexIdClass)
+                .getClass());
+
+        ITypeTraits[] typeTraits = new ITypeTraits[2];
+        typeTraits[0] = new TypeTraits(false);
+        typeTraits[1] = new TypeTraits(false);
+
+        BTreeSearchOperatorDescriptor scanner = new BTreeSearchOperatorDescriptor(spec, recordDescriptor,
+                storageManagerInterface, lcManagerProvider, secondaryFileSplitProviderRead, typeTraits,
+                comparatorFactories, null, null, null, true, true, getIndexDataflowHelperFactory(), false,
+                NoOpOperationCallbackFactory.INSTANCE);
+        ClusterConfig.setLocationConstraint(spec, scanner);
+
+        /**
+         * construct write file operator
+         */
+        IRecordDescriptorFactory inputRdFactory = DataflowUtils.getWritableRecordDescriptorFactoryFromWritableClasses(
+                vertexIdClass.getName(), MsgList.class.getName());
+        HDFSFileWriteOperatorDescriptor writer = new HDFSFileWriteOperatorDescriptor(spec, job, inputRdFactory);
+        ClusterConfig.setLocationConstraint(spec, writer);
+
+        /**
+         * connect operator descriptors
+         */
+        spec.connect(new OneToOneConnectorDescriptor(spec), emptyTupleSource, 0, scanner, 0);
+        spec.connect(new OneToOneConnectorDescriptor(spec), scanner, 0, writer, 0);
+        spec.setFrameSize(frameSize);
+        return spec;
+    }
+
     @Override
     public JobSpecification[] generateCleanup() throws HyracksException {
         JobSpecification[] cleanups = new JobSpecification[3];
diff --git a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGenOuterJoin.java b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGenOuterJoin.java
index 3af8921..287b797 100644
--- a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGenOuterJoin.java
+++ b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGenOuterJoin.java
@@ -32,8 +32,6 @@
 import edu.uci.ics.hyracks.dataflow.std.connectors.MToNPartitioningMergingConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.connectors.OneToOneConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.file.IFileSplitProvider;
-import edu.uci.ics.hyracks.dataflow.std.group.IAggregatorDescriptorFactory;
-import edu.uci.ics.hyracks.dataflow.std.group.preclustered.PreclusteredGroupOperatorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.sort.ExternalSortOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.TreeIndexInsertUpdateDeleteOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallbackFactory;
@@ -54,6 +52,8 @@
 import edu.uci.ics.pregelix.dataflow.MaterializingWriteOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.TerminationStateWriterOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.base.IConfigurationFactory;
+import edu.uci.ics.pregelix.dataflow.group.ClusteredGroupOperatorDescriptor;
+import edu.uci.ics.pregelix.dataflow.group.IClusteredAggregatorDescriptorFactory;
 import edu.uci.ics.pregelix.dataflow.std.IndexNestedLoopJoinFunctionUpdateOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.std.RuntimeHookOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.std.TreeSearchFunctionUpdateOperatorDescriptor;
@@ -144,9 +144,9 @@
         /**
          * construct local pre-clustered group-by operator
          */
-        IAggregatorDescriptorFactory aggregatorFactory = DataflowUtils.getAccumulatingAggregatorFactory(conf, false,
-                false);
-        PreclusteredGroupOperatorDescriptor localGby = new PreclusteredGroupOperatorDescriptor(spec, keyFields,
+        IClusteredAggregatorDescriptorFactory aggregatorFactory = DataflowUtils.getAccumulatingAggregatorFactory(conf,
+                false, false);
+        ClusteredGroupOperatorDescriptor localGby = new ClusteredGroupOperatorDescriptor(spec, keyFields,
                 sortCmpFactories, aggregatorFactory, rdUnnestedMessage);
         ClusterConfig.setLocationConstraint(spec, localGby);
 
@@ -155,9 +155,9 @@
          */
         RecordDescriptor rdFinal = DataflowUtils.getRecordDescriptorFromKeyValueClasses(vertexIdClass.getName(),
                 MsgList.class.getName());
-        IAggregatorDescriptorFactory aggregatorFactoryFinal = DataflowUtils.getAccumulatingAggregatorFactory(conf,
-                true, true);
-        PreclusteredGroupOperatorDescriptor globalGby = new PreclusteredGroupOperatorDescriptor(spec, keyFields,
+        IClusteredAggregatorDescriptorFactory aggregatorFactoryFinal = DataflowUtils.getAccumulatingAggregatorFactory(
+                conf, true, true);
+        ClusteredGroupOperatorDescriptor globalGby = new ClusteredGroupOperatorDescriptor(spec, keyFields,
                 sortCmpFactories, aggregatorFactoryFinal, rdFinal);
         ClusterConfig.setLocationConstraint(spec, globalGby);
 
@@ -198,8 +198,8 @@
         int[] fieldPermutation = new int[] { 0, 1 };
         TreeIndexInsertUpdateDeleteOperatorDescriptor insertOp = new TreeIndexInsertUpdateDeleteOperatorDescriptor(
                 spec, rdInsert, storageManagerInterface, lcManagerProvider, fileSplitProvider, typeTraits,
-                comparatorFactories, null, fieldPermutation, IndexOperation.INSERT, getIndexDataflowHelperFactory(), null,
-                NoOpOperationCallbackFactory.INSTANCE);
+                comparatorFactories, null, fieldPermutation, IndexOperation.INSERT, getIndexDataflowHelperFactory(),
+                null, NoOpOperationCallbackFactory.INSTANCE);
         ClusterConfig.setLocationConstraint(spec, insertOp);
 
         /**
@@ -208,8 +208,8 @@
         int[] fieldPermutationDelete = new int[] { 0 };
         TreeIndexInsertUpdateDeleteOperatorDescriptor deleteOp = new TreeIndexInsertUpdateDeleteOperatorDescriptor(
                 spec, rdDelete, storageManagerInterface, lcManagerProvider, fileSplitProvider, typeTraits,
-                comparatorFactories, null, fieldPermutationDelete, IndexOperation.DELETE, getIndexDataflowHelperFactory(),
-                null, NoOpOperationCallbackFactory.INSTANCE);
+                comparatorFactories, null, fieldPermutationDelete, IndexOperation.DELETE,
+                getIndexDataflowHelperFactory(), null, NoOpOperationCallbackFactory.INSTANCE);
         ClusterConfig.setLocationConstraint(spec, deleteOp);
 
         /** construct empty sink operator */
@@ -299,7 +299,8 @@
         /**
          * construct the materializing write operator
          */
-        MaterializingReadOperatorDescriptor materializeRead = new MaterializingReadOperatorDescriptor(spec, rdFinal);
+        MaterializingReadOperatorDescriptor materializeRead = new MaterializingReadOperatorDescriptor(spec, rdFinal,
+                true);
         ClusterConfig.setLocationConstraint(spec, materializeRead);
 
         /**
@@ -323,9 +324,10 @@
 
         IndexNestedLoopJoinFunctionUpdateOperatorDescriptor join = new IndexNestedLoopJoinFunctionUpdateOperatorDescriptor(
                 spec, storageManagerInterface, lcManagerProvider, fileSplitProvider, typeTraits, comparatorFactories,
-                JobGenUtil.getForwardScan(iteration), keyFields, keyFields, true, true, getIndexDataflowHelperFactory(), true,
-                nullWriterFactories, inputRdFactory, 5, new ComputeUpdateFunctionFactory(confFactory), preHookFactory,
-                null, rdUnnestedMessage, rdDummy, rdPartialAggregate, rdInsert, rdDelete);
+                JobGenUtil.getForwardScan(iteration), keyFields, keyFields, true, true,
+                getIndexDataflowHelperFactory(), true, nullWriterFactories, inputRdFactory, 5,
+                new ComputeUpdateFunctionFactory(confFactory), preHookFactory, null, rdUnnestedMessage, rdDummy,
+                rdPartialAggregate, rdInsert, rdDelete);
         ClusterConfig.setLocationConstraint(spec, join);
 
         /**
@@ -342,18 +344,18 @@
         /**
          * construct local pre-clustered group-by operator
          */
-        IAggregatorDescriptorFactory aggregatorFactory = DataflowUtils.getAccumulatingAggregatorFactory(conf, false,
-                false);
-        PreclusteredGroupOperatorDescriptor localGby = new PreclusteredGroupOperatorDescriptor(spec, keyFields,
+        IClusteredAggregatorDescriptorFactory aggregatorFactory = DataflowUtils.getAccumulatingAggregatorFactory(conf,
+                false, false);
+        ClusteredGroupOperatorDescriptor localGby = new ClusteredGroupOperatorDescriptor(spec, keyFields,
                 sortCmpFactories, aggregatorFactory, rdUnnestedMessage);
         ClusterConfig.setLocationConstraint(spec, localGby);
 
         /**
          * construct global group-by operator
          */
-        IAggregatorDescriptorFactory aggregatorFactoryFinal = DataflowUtils.getAccumulatingAggregatorFactory(conf,
-                true, true);
-        PreclusteredGroupOperatorDescriptor globalGby = new PreclusteredGroupOperatorDescriptor(spec, keyFields,
+        IClusteredAggregatorDescriptorFactory aggregatorFactoryFinal = DataflowUtils.getAccumulatingAggregatorFactory(
+                conf, true, true);
+        ClusteredGroupOperatorDescriptor globalGby = new ClusteredGroupOperatorDescriptor(spec, keyFields,
                 sortCmpFactories, aggregatorFactoryFinal, rdFinal);
         ClusterConfig.setLocationConstraint(spec, globalGby);
 
@@ -394,8 +396,8 @@
         int[] fieldPermutation = new int[] { 0, 1 };
         TreeIndexInsertUpdateDeleteOperatorDescriptor insertOp = new TreeIndexInsertUpdateDeleteOperatorDescriptor(
                 spec, rdInsert, storageManagerInterface, lcManagerProvider, fileSplitProvider, typeTraits,
-                comparatorFactories, null, fieldPermutation, IndexOperation.INSERT, getIndexDataflowHelperFactory(), null,
-                NoOpOperationCallbackFactory.INSTANCE);
+                comparatorFactories, null, fieldPermutation, IndexOperation.INSERT, getIndexDataflowHelperFactory(),
+                null, NoOpOperationCallbackFactory.INSTANCE);
         ClusterConfig.setLocationConstraint(spec, insertOp);
 
         /**
@@ -404,8 +406,8 @@
         int[] fieldPermutationDelete = new int[] { 0 };
         TreeIndexInsertUpdateDeleteOperatorDescriptor deleteOp = new TreeIndexInsertUpdateDeleteOperatorDescriptor(
                 spec, rdDelete, storageManagerInterface, lcManagerProvider, fileSplitProvider, typeTraits,
-                comparatorFactories, null, fieldPermutationDelete, IndexOperation.DELETE, getIndexDataflowHelperFactory(),
-                null, NoOpOperationCallbackFactory.INSTANCE);
+                comparatorFactories, null, fieldPermutationDelete, IndexOperation.DELETE,
+                getIndexDataflowHelperFactory(), null, NoOpOperationCallbackFactory.INSTANCE);
         ClusterConfig.setLocationConstraint(spec, deleteOp);
 
         /** construct empty sink operator */
diff --git a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGenOuterJoinSingleSort.java b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGenOuterJoinSingleSort.java
index 50949aa..3b3c9e7 100644
--- a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGenOuterJoinSingleSort.java
+++ b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGenOuterJoinSingleSort.java
@@ -31,8 +31,6 @@
 import edu.uci.ics.hyracks.dataflow.std.connectors.MToNPartitioningConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.connectors.OneToOneConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.file.IFileSplitProvider;
-import edu.uci.ics.hyracks.dataflow.std.group.IAggregatorDescriptorFactory;
-import edu.uci.ics.hyracks.dataflow.std.group.preclustered.PreclusteredGroupOperatorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.sort.ExternalSortOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.TreeIndexInsertUpdateDeleteOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallbackFactory;
@@ -53,6 +51,8 @@
 import edu.uci.ics.pregelix.dataflow.MaterializingWriteOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.TerminationStateWriterOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.base.IConfigurationFactory;
+import edu.uci.ics.pregelix.dataflow.group.ClusteredGroupOperatorDescriptor;
+import edu.uci.ics.pregelix.dataflow.group.IClusteredAggregatorDescriptorFactory;
 import edu.uci.ics.pregelix.dataflow.std.IndexNestedLoopJoinFunctionUpdateOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.std.RuntimeHookOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.std.TreeSearchFunctionUpdateOperatorDescriptor;
@@ -148,9 +148,9 @@
          */
         RecordDescriptor rdFinal = DataflowUtils.getRecordDescriptorFromKeyValueClasses(vertexIdClass.getName(),
                 MsgList.class.getName());
-        IAggregatorDescriptorFactory aggregatorFactoryFinal = DataflowUtils.getAccumulatingAggregatorFactory(conf,
-                true, false);
-        PreclusteredGroupOperatorDescriptor globalGby = new PreclusteredGroupOperatorDescriptor(spec, keyFields,
+        IClusteredAggregatorDescriptorFactory aggregatorFactoryFinal = DataflowUtils.getAccumulatingAggregatorFactory(
+                conf, true, false);
+        ClusteredGroupOperatorDescriptor globalGby = new ClusteredGroupOperatorDescriptor(spec, keyFields,
                 sortCmpFactories, aggregatorFactoryFinal, rdFinal);
         ClusterConfig.setLocationConstraint(spec, globalGby);
 
@@ -190,8 +190,8 @@
         int[] fieldPermutation = new int[] { 0, 1 };
         TreeIndexInsertUpdateDeleteOperatorDescriptor insertOp = new TreeIndexInsertUpdateDeleteOperatorDescriptor(
                 spec, rdInsert, storageManagerInterface, lcManagerProvider, fileSplitProvider, typeTraits,
-                comparatorFactories, null, fieldPermutation, IndexOperation.INSERT, getIndexDataflowHelperFactory(), null,
-                NoOpOperationCallbackFactory.INSTANCE);
+                comparatorFactories, null, fieldPermutation, IndexOperation.INSERT, getIndexDataflowHelperFactory(),
+                null, NoOpOperationCallbackFactory.INSTANCE);
         ClusterConfig.setLocationConstraint(spec, insertOp);
 
         /**
@@ -200,8 +200,8 @@
         int[] fieldPermutationDelete = new int[] { 0 };
         TreeIndexInsertUpdateDeleteOperatorDescriptor deleteOp = new TreeIndexInsertUpdateDeleteOperatorDescriptor(
                 spec, rdDelete, storageManagerInterface, lcManagerProvider, fileSplitProvider, typeTraits,
-                comparatorFactories, null, fieldPermutationDelete, IndexOperation.DELETE, getIndexDataflowHelperFactory(),
-                null, NoOpOperationCallbackFactory.INSTANCE);
+                comparatorFactories, null, fieldPermutationDelete, IndexOperation.DELETE,
+                getIndexDataflowHelperFactory(), null, NoOpOperationCallbackFactory.INSTANCE);
         ClusterConfig.setLocationConstraint(spec, deleteOp);
 
         /** construct empty sink operator */
@@ -288,7 +288,8 @@
         /**
          * construct the materializing write operator
          */
-        MaterializingReadOperatorDescriptor materializeRead = new MaterializingReadOperatorDescriptor(spec, rdFinal);
+        MaterializingReadOperatorDescriptor materializeRead = new MaterializingReadOperatorDescriptor(spec, rdFinal,
+                true);
         ClusterConfig.setLocationConstraint(spec, materializeRead);
 
         /**
@@ -312,9 +313,10 @@
 
         IndexNestedLoopJoinFunctionUpdateOperatorDescriptor join = new IndexNestedLoopJoinFunctionUpdateOperatorDescriptor(
                 spec, storageManagerInterface, lcManagerProvider, fileSplitProvider, typeTraits, comparatorFactories,
-                JobGenUtil.getForwardScan(iteration), keyFields, keyFields, true, true, getIndexDataflowHelperFactory(), true,
-                nullWriterFactories, inputRdFactory, 5, new ComputeUpdateFunctionFactory(confFactory), preHookFactory,
-                null, rdUnnestedMessage, rdDummy, rdPartialAggregate, rdInsert, rdDelete);
+                JobGenUtil.getForwardScan(iteration), keyFields, keyFields, true, true,
+                getIndexDataflowHelperFactory(), true, nullWriterFactories, inputRdFactory, 5,
+                new ComputeUpdateFunctionFactory(confFactory), preHookFactory, null, rdUnnestedMessage, rdDummy,
+                rdPartialAggregate, rdInsert, rdDelete);
         ClusterConfig.setLocationConstraint(spec, join);
 
         /**
@@ -331,9 +333,9 @@
         /**
          * construct global group-by operator
          */
-        IAggregatorDescriptorFactory aggregatorFactoryFinal = DataflowUtils.getAccumulatingAggregatorFactory(conf,
-                true, false);
-        PreclusteredGroupOperatorDescriptor globalGby = new PreclusteredGroupOperatorDescriptor(spec, keyFields,
+        IClusteredAggregatorDescriptorFactory aggregatorFactoryFinal = DataflowUtils.getAccumulatingAggregatorFactory(
+                conf, true, false);
+        ClusteredGroupOperatorDescriptor globalGby = new ClusteredGroupOperatorDescriptor(spec, keyFields,
                 sortCmpFactories, aggregatorFactoryFinal, rdFinal);
         ClusterConfig.setLocationConstraint(spec, globalGby);
 
@@ -371,8 +373,8 @@
         int[] fieldPermutation = new int[] { 0, 1 };
         TreeIndexInsertUpdateDeleteOperatorDescriptor insertOp = new TreeIndexInsertUpdateDeleteOperatorDescriptor(
                 spec, rdInsert, storageManagerInterface, lcManagerProvider, fileSplitProvider, typeTraits,
-                comparatorFactories, null, fieldPermutation, IndexOperation.INSERT, getIndexDataflowHelperFactory(), null,
-                NoOpOperationCallbackFactory.INSTANCE);
+                comparatorFactories, null, fieldPermutation, IndexOperation.INSERT, getIndexDataflowHelperFactory(),
+                null, NoOpOperationCallbackFactory.INSTANCE);
         ClusterConfig.setLocationConstraint(spec, insertOp);
 
         /**
@@ -381,8 +383,8 @@
         int[] fieldPermutationDelete = new int[] { 0 };
         TreeIndexInsertUpdateDeleteOperatorDescriptor deleteOp = new TreeIndexInsertUpdateDeleteOperatorDescriptor(
                 spec, rdDelete, storageManagerInterface, lcManagerProvider, fileSplitProvider, typeTraits,
-                comparatorFactories, null, fieldPermutationDelete, IndexOperation.DELETE, getIndexDataflowHelperFactory(),
-                null, NoOpOperationCallbackFactory.INSTANCE);
+                comparatorFactories, null, fieldPermutationDelete, IndexOperation.DELETE,
+                getIndexDataflowHelperFactory(), null, NoOpOperationCallbackFactory.INSTANCE);
         ClusterConfig.setLocationConstraint(spec, deleteOp);
 
         /** construct empty sink operator */
diff --git a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGenOuterJoinSort.java b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGenOuterJoinSort.java
index 362e413..e334095 100644
--- a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGenOuterJoinSort.java
+++ b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGenOuterJoinSort.java
@@ -31,8 +31,6 @@
 import edu.uci.ics.hyracks.dataflow.std.connectors.MToNPartitioningConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.connectors.OneToOneConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.file.IFileSplitProvider;
-import edu.uci.ics.hyracks.dataflow.std.group.IAggregatorDescriptorFactory;
-import edu.uci.ics.hyracks.dataflow.std.group.preclustered.PreclusteredGroupOperatorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.sort.ExternalSortOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.TreeIndexInsertUpdateDeleteOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallbackFactory;
@@ -53,6 +51,8 @@
 import edu.uci.ics.pregelix.dataflow.MaterializingWriteOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.TerminationStateWriterOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.base.IConfigurationFactory;
+import edu.uci.ics.pregelix.dataflow.group.ClusteredGroupOperatorDescriptor;
+import edu.uci.ics.pregelix.dataflow.group.IClusteredAggregatorDescriptorFactory;
 import edu.uci.ics.pregelix.dataflow.std.IndexNestedLoopJoinFunctionUpdateOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.std.RuntimeHookOperatorDescriptor;
 import edu.uci.ics.pregelix.dataflow.std.TreeSearchFunctionUpdateOperatorDescriptor;
@@ -143,9 +143,9 @@
         /**
          * construct local pre-clustered group-by operator
          */
-        IAggregatorDescriptorFactory aggregatorFactory = DataflowUtils.getAccumulatingAggregatorFactory(conf, false,
-                false);
-        PreclusteredGroupOperatorDescriptor localGby = new PreclusteredGroupOperatorDescriptor(spec, keyFields,
+        IClusteredAggregatorDescriptorFactory aggregatorFactory = DataflowUtils.getAccumulatingAggregatorFactory(conf,
+                false, false);
+        ClusteredGroupOperatorDescriptor localGby = new ClusteredGroupOperatorDescriptor(spec, keyFields,
                 sortCmpFactories, aggregatorFactory, rdUnnestedMessage);
         ClusterConfig.setLocationConstraint(spec, localGby);
 
@@ -161,9 +161,9 @@
          */
         RecordDescriptor rdFinal = DataflowUtils.getRecordDescriptorFromKeyValueClasses(vertexIdClass.getName(),
                 MsgList.class.getName());
-        IAggregatorDescriptorFactory aggregatorFactoryFinal = DataflowUtils.getAccumulatingAggregatorFactory(conf,
-                true, true);
-        PreclusteredGroupOperatorDescriptor globalGby = new PreclusteredGroupOperatorDescriptor(spec, keyFields,
+        IClusteredAggregatorDescriptorFactory aggregatorFactoryFinal = DataflowUtils.getAccumulatingAggregatorFactory(
+                conf, true, true);
+        ClusteredGroupOperatorDescriptor globalGby = new ClusteredGroupOperatorDescriptor(spec, keyFields,
                 sortCmpFactories, aggregatorFactoryFinal, rdFinal);
         ClusterConfig.setLocationConstraint(spec, globalGby);
 
@@ -204,8 +204,8 @@
         int[] fieldPermutation = new int[] { 0, 1 };
         TreeIndexInsertUpdateDeleteOperatorDescriptor insertOp = new TreeIndexInsertUpdateDeleteOperatorDescriptor(
                 spec, rdInsert, storageManagerInterface, lcManagerProvider, fileSplitProvider, typeTraits,
-                comparatorFactories, null, fieldPermutation, IndexOperation.INSERT, getIndexDataflowHelperFactory(), null,
-                NoOpOperationCallbackFactory.INSTANCE);
+                comparatorFactories, null, fieldPermutation, IndexOperation.INSERT, getIndexDataflowHelperFactory(),
+                null, NoOpOperationCallbackFactory.INSTANCE);
         ClusterConfig.setLocationConstraint(spec, insertOp);
 
         /**
@@ -214,8 +214,8 @@
         int[] fieldPermutationDelete = new int[] { 0 };
         TreeIndexInsertUpdateDeleteOperatorDescriptor deleteOp = new TreeIndexInsertUpdateDeleteOperatorDescriptor(
                 spec, rdDelete, storageManagerInterface, lcManagerProvider, fileSplitProvider, typeTraits,
-                comparatorFactories, null, fieldPermutationDelete, IndexOperation.DELETE, getIndexDataflowHelperFactory(),
-                null, NoOpOperationCallbackFactory.INSTANCE);
+                comparatorFactories, null, fieldPermutationDelete, IndexOperation.DELETE,
+                getIndexDataflowHelperFactory(), null, NoOpOperationCallbackFactory.INSTANCE);
         ClusterConfig.setLocationConstraint(spec, deleteOp);
 
         /** construct empty sink operator */
@@ -302,7 +302,8 @@
         /**
          * construct the materializing write operator
          */
-        MaterializingReadOperatorDescriptor materializeRead = new MaterializingReadOperatorDescriptor(spec, rdFinal);
+        MaterializingReadOperatorDescriptor materializeRead = new MaterializingReadOperatorDescriptor(spec, rdFinal,
+                true);
         ClusterConfig.setLocationConstraint(spec, materializeRead);
 
         /**
@@ -326,9 +327,10 @@
 
         IndexNestedLoopJoinFunctionUpdateOperatorDescriptor join = new IndexNestedLoopJoinFunctionUpdateOperatorDescriptor(
                 spec, storageManagerInterface, lcManagerProvider, fileSplitProvider, typeTraits, comparatorFactories,
-                JobGenUtil.getForwardScan(iteration), keyFields, keyFields, true, true, getIndexDataflowHelperFactory(), true,
-                nullWriterFactories, inputRdFactory, 5, new ComputeUpdateFunctionFactory(confFactory), preHookFactory,
-                null, rdUnnestedMessage, rdDummy, rdPartialAggregate, rdInsert, rdDelete);
+                JobGenUtil.getForwardScan(iteration), keyFields, keyFields, true, true,
+                getIndexDataflowHelperFactory(), true, nullWriterFactories, inputRdFactory, 5,
+                new ComputeUpdateFunctionFactory(confFactory), preHookFactory, null, rdUnnestedMessage, rdDummy,
+                rdPartialAggregate, rdInsert, rdDelete);
         ClusterConfig.setLocationConstraint(spec, join);
 
         /**
@@ -345,9 +347,9 @@
         /**
          * construct local pre-clustered group-by operator
          */
-        IAggregatorDescriptorFactory aggregatorFactory = DataflowUtils.getAccumulatingAggregatorFactory(conf, false,
-                false);
-        PreclusteredGroupOperatorDescriptor localGby = new PreclusteredGroupOperatorDescriptor(spec, keyFields,
+        IClusteredAggregatorDescriptorFactory aggregatorFactory = DataflowUtils.getAccumulatingAggregatorFactory(conf,
+                false, false);
+        ClusteredGroupOperatorDescriptor localGby = new ClusteredGroupOperatorDescriptor(spec, keyFields,
                 sortCmpFactories, aggregatorFactory, rdUnnestedMessage);
         ClusterConfig.setLocationConstraint(spec, localGby);
 
@@ -361,9 +363,9 @@
         /**
          * construct global group-by operator
          */
-        IAggregatorDescriptorFactory aggregatorFactoryFinal = DataflowUtils.getAccumulatingAggregatorFactory(conf,
-                true, true);
-        PreclusteredGroupOperatorDescriptor globalGby = new PreclusteredGroupOperatorDescriptor(spec, keyFields,
+        IClusteredAggregatorDescriptorFactory aggregatorFactoryFinal = DataflowUtils.getAccumulatingAggregatorFactory(
+                conf, true, true);
+        ClusteredGroupOperatorDescriptor globalGby = new ClusteredGroupOperatorDescriptor(spec, keyFields,
                 sortCmpFactories, aggregatorFactoryFinal, rdFinal);
         ClusterConfig.setLocationConstraint(spec, globalGby);
 
@@ -404,8 +406,8 @@
         int[] fieldPermutation = new int[] { 0, 1 };
         TreeIndexInsertUpdateDeleteOperatorDescriptor insertOp = new TreeIndexInsertUpdateDeleteOperatorDescriptor(
                 spec, rdInsert, storageManagerInterface, lcManagerProvider, fileSplitProvider, typeTraits,
-                comparatorFactories, null, fieldPermutation, IndexOperation.INSERT, getIndexDataflowHelperFactory(), null,
-                NoOpOperationCallbackFactory.INSTANCE);
+                comparatorFactories, null, fieldPermutation, IndexOperation.INSERT, getIndexDataflowHelperFactory(),
+                null, NoOpOperationCallbackFactory.INSTANCE);
         ClusterConfig.setLocationConstraint(spec, insertOp);
 
         /**
@@ -414,8 +416,8 @@
         int[] fieldPermutationDelete = new int[] { 0 };
         TreeIndexInsertUpdateDeleteOperatorDescriptor deleteOp = new TreeIndexInsertUpdateDeleteOperatorDescriptor(
                 spec, rdDelete, storageManagerInterface, lcManagerProvider, fileSplitProvider, typeTraits,
-                comparatorFactories, null, fieldPermutationDelete, IndexOperation.DELETE, getIndexDataflowHelperFactory(),
-                null, NoOpOperationCallbackFactory.INSTANCE);
+                comparatorFactories, null, fieldPermutationDelete, IndexOperation.DELETE,
+                getIndexDataflowHelperFactory(), null, NoOpOperationCallbackFactory.INSTANCE);
         ClusterConfig.setLocationConstraint(spec, deleteOp);
 
         /** construct empty sink operator */
diff --git a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/clusterconfig/ClusterConfig.java b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/clusterconfig/ClusterConfig.java
index 49309ec..89fbdcd 100644
--- a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/clusterconfig/ClusterConfig.java
+++ b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/clusterconfig/ClusterConfig.java
@@ -20,12 +20,16 @@
 import java.net.InetAddress;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Properties;
 import java.util.Random;
+import java.util.Set;
+import java.util.TreeMap;
 
 import org.apache.hadoop.mapreduce.InputSplit;
 
@@ -51,6 +55,8 @@
     private static Map<String, List<String>> ipToNcMapping;
     private static String[] stores;
     private static Scheduler hdfsScheduler;
+    private static Set<String> blackListNodes = new HashSet<String>();
+    private static IHyracksClientConnection hcc;
 
     /**
      * let tests set config path to be whatever
@@ -196,8 +202,19 @@
 
     public static void loadClusterConfig(String ipAddress, int port) throws HyracksException {
         try {
-            IHyracksClientConnection hcc = new HyracksConnection(ipAddress, port);
-            Map<String, NodeControllerInfo> ncNameToNcInfos = hcc.getNodeControllerInfos();
+            if (hcc == null) {
+                hcc = new HyracksConnection(ipAddress, port);
+            }
+            Map<String, NodeControllerInfo> ncNameToNcInfos = new TreeMap<String, NodeControllerInfo>();
+            ncNameToNcInfos.putAll(hcc.getNodeControllerInfos());
+
+            /**
+             * remove black list nodes -- which had disk failures
+             */
+            for (String blackListNode : blackListNodes) {
+                ncNameToNcInfos.remove(blackListNode);
+            }
+
             NCs = new String[ncNameToNcInfos.size()];
             ipToNcMapping = new HashMap<String, List<String>>();
             int i = 0;
@@ -214,7 +231,7 @@
                 i++;
             }
 
-            hdfsScheduler = new Scheduler(ipAddress, port);
+            hdfsScheduler = new Scheduler(hcc.getNodeControllerInfos(), hcc.getClusterTopology());
         } catch (Exception e) {
             throw new IllegalStateException(e);
         }
@@ -226,4 +243,20 @@
     public static Scheduler getHdfsScheduler() {
         return hdfsScheduler;
     }
+
+    public static String[] getLocationConstraint() throws HyracksException {
+        int count = 0;
+        String[] locations = new String[NCs.length * stores.length];
+        for (String nc : NCs) {
+            for (int i = 0; i < stores.length; i++) {
+                locations[count] = nc;
+                count++;
+            }
+        }
+        return locations;
+    }
+
+    public static void addToBlackListNodes(Collection<String> nodes) {
+        blackListNodes.addAll(nodes);
+    }
 }
diff --git a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/util/DataflowUtils.java b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/util/DataflowUtils.java
index 0876893..3e01109 100644
--- a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/util/DataflowUtils.java
+++ b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/util/DataflowUtils.java
@@ -21,9 +21,9 @@
 import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
-import edu.uci.ics.hyracks.dataflow.std.group.IAggregatorDescriptorFactory;
 import edu.uci.ics.pregelix.core.hadoop.config.ConfigurationFactory;
 import edu.uci.ics.pregelix.core.runtime.touchpoint.WritableRecordDescriptorFactory;
+import edu.uci.ics.pregelix.dataflow.group.IClusteredAggregatorDescriptorFactory;
 import edu.uci.ics.pregelix.dataflow.std.base.IAggregateFunctionFactory;
 import edu.uci.ics.pregelix.dataflow.std.base.IRecordDescriptorFactory;
 import edu.uci.ics.pregelix.runtime.simpleagg.AccumulatingAggregatorFactory;
@@ -75,11 +75,11 @@
         return rdFactory;
     }
 
-    public static IAggregatorDescriptorFactory getAccumulatingAggregatorFactory(Configuration conf, boolean isFinal,
-            boolean partialAggAsInput) {
+    public static IClusteredAggregatorDescriptorFactory getAccumulatingAggregatorFactory(Configuration conf,
+            boolean isFinal, boolean partialAggAsInput) {
         IAggregateFunctionFactory aggFuncFactory = new AggregationFunctionFactory(new ConfigurationFactory(conf),
                 isFinal, partialAggAsInput);
-        IAggregatorDescriptorFactory aggregatorFactory = new AccumulatingAggregatorFactory(
+        IClusteredAggregatorDescriptorFactory aggregatorFactory = new AccumulatingAggregatorFactory(
                 new IAggregateFunctionFactory[] { aggFuncFactory });
         return aggregatorFactory;
     }
diff --git a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/util/ExceptionUtilities.java b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/util/ExceptionUtilities.java
new file mode 100644
index 0000000..a4c4501
--- /dev/null
+++ b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/util/ExceptionUtilities.java
@@ -0,0 +1,88 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.core.util;
+
+import java.io.IOException;
+import java.util.Set;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+
+/**
+ * The util to analysis exceptions
+ * 
+ * @author yingyib
+ */
+public class ExceptionUtilities {
+
+    /**
+     * Check whether a exception is recoverable or not
+     * 
+     * @param exception
+     * @return true or false
+     */
+    public static boolean recoverable(Exception exception, Set<String> blackListNodes) {
+        String message = exception.getMessage();
+
+        /***
+         * check interrupted exception
+         */
+        if (exception instanceof InterruptedException || (message.contains("Node") && message.contains("not live"))
+                || message.contains("Failure occurred on input")) {
+            return true;
+        }
+        Throwable cause = exception;
+        while ((cause = cause.getCause()) != null) {
+            if (cause instanceof InterruptedException) {
+                return true;
+            }
+        }
+
+        /***
+         * check io exception
+         */
+        cause = exception;
+        String blackListNode = null;
+        if (cause instanceof HyracksDataException) {
+            blackListNode = ((HyracksDataException) cause).getNodeId();
+        }
+        while ((cause = cause.getCause()) != null) {
+            if (cause instanceof IOException) {
+                if (containsIOManager(cause)) {
+                    if (blackListNode != null) {
+                        blackListNodes.add(blackListNode);
+                    }
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
+    /**
+     * Check if the exception traces contains the IOManager, which means there are disk failures
+     * 
+     * @param cause
+     * @return true if IOManager is in the trace; false otherwise.
+     */
+    private static boolean containsIOManager(Throwable cause) {
+        StackTraceElement[] traces = cause.getStackTrace();
+        for (StackTraceElement e : traces) {
+            if (e.getClassName().endsWith("IOManager")) {
+                return true;
+            }
+        }
+        return false;
+    }
+}
diff --git a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/util/PregelixHyracksIntegrationUtil.java b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/util/PregelixHyracksIntegrationUtil.java
index 73b053f..aabd4ba 100644
--- a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/util/PregelixHyracksIntegrationUtil.java
+++ b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/util/PregelixHyracksIntegrationUtil.java
@@ -14,8 +14,11 @@
  */
 package edu.uci.ics.pregelix.core.util;
 
+import java.io.File;
 import java.util.EnumSet;
 
+import org.apache.commons.io.FileUtils;
+
 import edu.uci.ics.hyracks.api.client.HyracksConnection;
 import edu.uci.ics.hyracks.api.client.IHyracksClientConnection;
 import edu.uci.ics.hyracks.api.job.JobFlag;
@@ -46,6 +49,10 @@
     private static IHyracksClientConnection hcc;
 
     public static void init() throws Exception {
+        FileUtils.forceMkdir(new File("dev1"));
+        FileUtils.forceMkdir(new File("dev2"));
+        FileUtils.forceMkdir(new File("dev3"));
+        FileUtils.forceMkdir(new File("dev4"));
         CCConfig ccConfig = new CCConfig();
         ccConfig.clientNetIpAddress = CC_HOST;
         ccConfig.clusterNetIpAddress = CC_HOST;
@@ -54,6 +61,8 @@
         ccConfig.defaultMaxJobAttempts = 0;
         ccConfig.jobHistorySize = 1;
         ccConfig.profileDumpPeriod = -1;
+        ccConfig.heartbeatPeriod = 50;
+        ccConfig.maxHeartbeatLapsePeriods = 15;
 
         // cluster controller
         cc = new ClusterControllerService(ccConfig);
@@ -67,7 +76,7 @@
         ncConfig1.dataIPAddress = "127.0.0.1";
         ncConfig1.datasetIPAddress = "127.0.0.1";
         ncConfig1.nodeId = NC1_ID;
-        ncConfig1.ioDevices="dev1,dev2";
+        ncConfig1.ioDevices = "dev1,dev2";
         ncConfig1.appNCMainClass = NCApplicationEntryPoint.class.getName();
         nc1 = new NodeControllerService(ncConfig1);
         nc1.start();
@@ -80,7 +89,7 @@
         ncConfig2.datasetIPAddress = "127.0.0.1";
         ncConfig2.nodeId = NC2_ID;
         ncConfig2.appNCMainClass = NCApplicationEntryPoint.class.getName();
-        ncConfig2.ioDevices="dev1,dev2";
+        ncConfig2.ioDevices = "dev3,dev4";
         nc2 = new NodeControllerService(ncConfig2);
         nc2.start();
 
@@ -89,6 +98,22 @@
         ClusterConfig.loadClusterConfig(CC_HOST, TEST_HYRACKS_CC_CLIENT_PORT);
     }
 
+    public static void startNC1() throws Exception {
+        nc1.start();
+    }
+
+    public static void shutdownNC1() throws Exception {
+        nc1.stop();
+    }
+
+    public static void shutdownNC2() throws Exception {
+        nc2.stop();
+    }
+
+    public static void shutdownCC() throws Exception {
+        cc.stop();
+    }
+
     public static void deinit() throws Exception {
         nc2.stop();
         nc1.stop();
diff --git a/pregelix/pregelix-core/src/main/resources/scripts/pregelix b/pregelix/pregelix-core/src/main/resources/scripts/pregelix
deleted file mode 100644
index 7232ccc..0000000
--- a/pregelix/pregelix-core/src/main/resources/scripts/pregelix
+++ /dev/null
@@ -1,111 +0,0 @@
-#!/bin/sh
-#
-#------------------------------------------------------------------------
-# Copyright 2009-2013 by The Regents of the University of California
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# you may obtain a copy of the License from
-# 
-#     http://www.apache.org/licenses/LICENSE-2.0
-# 
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-# ------------------------------------------------------------------------
-#
-
-
-# resolve links - $0 may be a softlink
-PRG="$0"
-
-while [ -h "$PRG" ]; do
-  ls=`ls -ld "$PRG"`
-  link=`expr "$ls" : '.*-> \(.*\)$'`
-  if expr "$link" : '/.*' > /dev/null; then
-    PRG="$link"
-  else
-    PRG=`dirname "$PRG"`/"$link"
-  fi
-done
-
-PRGDIR=`dirname "$PRG"`
-BASEDIR=`cd "$PRGDIR/.." >/dev/null; pwd`
-
-
-
-# OS specific support.  $var _must_ be set to either true or false.
-cygwin=false;
-darwin=false;
-case "`uname`" in
-  CYGWIN*) cygwin=true ;;
-  Darwin*) darwin=true
-           if [ -z "$JAVA_VERSION" ] ; then
-             JAVA_VERSION="CurrentJDK"
-           else
-             echo "Using Java version: $JAVA_VERSION"
-           fi
-           if [ -z "$JAVA_HOME" ] ; then
-             JAVA_HOME=/System/Library/Frameworks/JavaVM.framework/Versions/${JAVA_VERSION}/Home
-           fi
-           ;;
-esac
-
-if [ -z "$JAVA_HOME" ] ; then
-  if [ -r /etc/gentoo-release ] ; then
-    JAVA_HOME=`java-config --jre-home`
-  fi
-fi
-
-# For Cygwin, ensure paths are in UNIX format before anything is touched
-if $cygwin ; then
-  [ -n "$JAVA_HOME" ] && JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
-  [ -n "$CLASSPATH" ] && CLASSPATH=`cygpath --path --unix "$CLASSPATH"`
-fi
-
-# If a specific java binary isn't specified search for the standard 'java' binary
-if [ -z "$JAVACMD" ] ; then
-  if [ -n "$JAVA_HOME"  ] ; then
-    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
-      # IBM's JDK on AIX uses strange locations for the executables
-      JAVACMD="$JAVA_HOME/jre/sh/java"
-    else
-      JAVACMD="$JAVA_HOME/bin/java"
-    fi
-  else
-    JAVACMD=`which java`
-  fi
-fi
-
-if [ ! -x "$JAVACMD" ] ; then
-  echo "Error: JAVA_HOME is not defined correctly." 1>&2
-  echo "  We cannot execute $JAVACMD" 1>&2
-  exit 1
-fi
-
-if [ -z "$REPO" ]
-then
-  REPO="$BASEDIR"/lib
-fi
-
-CLASSPATH=$CLASSPATH_PREFIX:"$HADOOP_HOME"/conf:/etc/hadoop/conf:"$BASEDIR"/etc:$1
-
-# For Cygwin, switch paths to Windows format before running java
-if $cygwin; then
-  [ -n "$CLASSPATH" ] && CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
-  [ -n "$JAVA_HOME" ] && JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"`
-  [ -n "$HOME" ] && HOME=`cygpath --path --windows "$HOME"`
-  [ -n "$BASEDIR" ] && BASEDIR=`cygpath --path --windows "$BASEDIR"`
-  [ -n "$REPO" ] && REPO=`cygpath --path --windows "$REPO"`
-fi
-
-exec "$JAVACMD" $JAVA_OPTS  \
-  -classpath "$CLASSPATH" \
-  -Dapp.name="pregelix" \
-  -Dapp.pid="$$" \
-  -Dapp.repo="$REPO" \
-  -Dapp.home="$BASEDIR" \
-  -Dbasedir="$BASEDIR" \
-  org.apache.hadoop.util.RunJar \
-  "$@"
diff --git a/pregelix/pregelix-core/src/main/resources/scripts/pregelix.bat b/pregelix/pregelix-core/src/main/resources/scripts/pregelix.bat
deleted file mode 100644
index fe53029..0000000
--- a/pregelix/pregelix-core/src/main/resources/scripts/pregelix.bat
+++ /dev/null
@@ -1,124 +0,0 @@
-@rem /*
-@rem Copyright 2009-2013 by The Regents of the University of California
-@rem Licensed under the Apache License, Version 2.0 (the "License");
-@rem you may not use this file except in compliance with the License.
-@rem you may obtain a copy of the License from
-@rem 
-@rem     http://www.apache.org/licenses/LICENSE-2.0
-@rem 
-@rem Unless required by applicable law or agreed to in writing, software
-@rem distributed under the License is distributed on an "AS IS" BASIS,
-@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-@rem See the License for the specific language governing permissions and
-@rem limitations under the License.
-@rem */
-@REM ----------------------------------------------------------------------------
-@REM  Copyright 2001-2006 The Apache Software Foundation.
-@REM
-@REM  Licensed under the Apache License, Version 2.0 (the "License");
-@REM  you may not use this file except in compliance with the License.
-@REM  You may obtain a copy of the License at
-@REM
-@REM       http://www.apache.org/licenses/LICENSE-2.0
-@REM
-@REM  Unless required by applicable law or agreed to in writing, software
-@REM  distributed under the License is distributed on an "AS IS" BASIS,
-@REM  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-@REM  See the License for the specific language governing permissions and
-@REM  limitations under the License.
-@REM ----------------------------------------------------------------------------
-@REM
-@REM   Copyright (c) 2001-2006 The Apache Software Foundation.  All rights
-@REM   reserved.
-
-@echo off
-
-set ERROR_CODE=0
-
-:init
-@REM Decide how to startup depending on the version of windows
-
-@REM -- Win98ME
-if NOT "%OS%"=="Windows_NT" goto Win9xArg
-
-@REM set local scope for the variables with windows NT shell
-if "%OS%"=="Windows_NT" @setlocal
-
-@REM -- 4NT shell
-if "%eval[2+2]" == "4" goto 4NTArgs
-
-@REM -- Regular WinNT shell
-set CMD_LINE_ARGS=%*
-goto WinNTGetScriptDir
-
-@REM The 4NT Shell from jp software
-:4NTArgs
-set CMD_LINE_ARGS=%$
-goto WinNTGetScriptDir
-
-:Win9xArg
-@REM Slurp the command line arguments.  This loop allows for an unlimited number
-@REM of arguments (up to the command line limit, anyway).
-set CMD_LINE_ARGS=
-:Win9xApp
-if %1a==a goto Win9xGetScriptDir
-set CMD_LINE_ARGS=%CMD_LINE_ARGS% %1
-shift
-goto Win9xApp
-
-:Win9xGetScriptDir
-set SAVEDIR=%CD%
-%0\
-cd %0\..\.. 
-set BASEDIR=%CD%
-cd %SAVEDIR%
-set SAVE_DIR=
-goto repoSetup
-
-:WinNTGetScriptDir
-set BASEDIR=%~dp0\..
-
-:repoSetup
-
-
-if "%JAVACMD%"=="" set JAVACMD=java
-
-if "%REPO%"=="" set REPO=%BASEDIR%\lib
-
-cp $BASEDIR"\..\a-hadoop-patch.jar "$REPO"\
-
-set CLASSPATH="%BASEDIR%"\etc;"%REPO%"\a-hadoop-patch.jar;"%REPO%"\pregelix-api-0.0.1-SNAPSHOT.jar;"%REPO%"\hyracks-dataflow-common-0.2.2-SNAPSHOT.jar;"%REPO%"\hyracks-api-0.2.2-SNAPSHOT.jar;"%REPO%"\json-20090211.jar;"%REPO%"\httpclient-4.1-alpha2.jar;"%REPO%"\httpcore-4.1-beta1.jar;"%REPO%"\commons-logging-1.1.1.jar;"%REPO%"\commons-codec-1.3.jar;"%REPO%"\args4j-2.0.12.jar;"%REPO%"\hyracks-ipc-0.2.2-SNAPSHOT.jar;"%REPO%"\commons-lang3-3.1.jar;"%REPO%"\hyracks-data-std-0.2.2-SNAPSHOT.jar;"%REPO%"\hadoop-core-0.20.2.jar;"%REPO%"\commons-cli-1.2.jar;"%REPO%"\xmlenc-0.52.jar;"%REPO%"\commons-httpclient-3.0.1.jar;"%REPO%"\commons-net-1.4.1.jar;"%REPO%"\oro-2.0.8.jar;"%REPO%"\jetty-6.1.14.jar;"%REPO%"\jetty-util-6.1.14.jar;"%REPO%"\servlet-api-2.5-6.1.14.jar;"%REPO%"\jasper-runtime-5.5.12.jar;"%REPO%"\jasper-compiler-5.5.12.jar;"%REPO%"\jsp-api-2.1-6.1.14.jar;"%REPO%"\jsp-2.1-6.1.14.jar;"%REPO%"\core-3.1.1.jar;"%REPO%"\ant-1.6.5.jar;"%REPO%"\commons-el-1.0.jar;"%REPO%"\jets3t-0.7.1.jar;"%REPO%"\kfs-0.3.jar;"%REPO%"\hsqldb-1.8.0.10.jar;"%REPO%"\pregelix-dataflow-std-0.0.1-SNAPSHOT.jar;"%REPO%"\pregelix-dataflow-std-base-0.0.1-SNAPSHOT.jar;"%REPO%"\hyracks-dataflow-std-0.2.2-SNAPSHOT.jar;"%REPO%"\hyracks-dataflow-hadoop-0.2.2-SNAPSHOT.jar;"%REPO%"\dcache-client-0.0.1.jar;"%REPO%"\jetty-client-8.0.0.M0.jar;"%REPO%"\jetty-http-8.0.0.RC0.jar;"%REPO%"\jetty-io-8.0.0.RC0.jar;"%REPO%"\jetty-util-8.0.0.RC0.jar;"%REPO%"\hyracks-storage-am-common-0.2.2-SNAPSHOT.jar;"%REPO%"\hyracks-storage-common-0.2.2-SNAPSHOT.jar;"%REPO%"\hyracks-storage-am-btree-0.2.2-SNAPSHOT.jar;"%REPO%"\btreehelper-0.2.2-SNAPSHOT.jar;"%REPO%"\hyracks-control-cc-0.2.2-SNAPSHOT.jar;"%REPO%"\hyracks-control-common-0.2.2-SNAPSHOT.jar;"%REPO%"\commons-io-1.3.1.jar;"%REPO%"\jetty-server-8.0.0.RC0.jar;"%REPO%"\servlet-api-3.0.20100224.jar;"%REPO%"\jetty-continuation-8.0.0.RC0.jar;"%REPO%"\jetty-webapp-8.0.0.RC0.jar;"%REPO%"\jetty-xml-8.0.0.RC0.jar;"%REPO%"\jetty-servlet-8.0.0.RC0.jar;"%REPO%"\jetty-security-8.0.0.RC0.jar;"%REPO%"\wicket-core-1.5.2.jar;"%REPO%"\wicket-util-1.5.2.jar;"%REPO%"\slf4j-api-1.6.1.jar;"%REPO%"\wicket-request-1.5.2.jar;"%REPO%"\slf4j-jcl-1.6.3.jar;"%REPO%"\hyracks-control-nc-0.2.2-SNAPSHOT.jar;"%REPO%"\hyracks-net-0.2.2-SNAPSHOT.jar;"%REPO%"\hyracks-hadoop-compat-0.2.2-SNAPSHOT.jar;"%REPO%"\pregelix-dataflow-0.0.1-SNAPSHOT.jar;"%REPO%"\pregelix-runtime-0.0.1-SNAPSHOT.jar;"%REPO%"\hadoop-test-0.20.2.jar;"%REPO%"\ftplet-api-1.0.0.jar;"%REPO%"\mina-core-2.0.0-M5.jar;"%REPO%"\ftpserver-core-1.0.0.jar;"%REPO%"\ftpserver-deprecated-1.0.0-M2.jar;"%REPO%"\javax.servlet-api-3.0.1.jar;"%REPO%"\pregelix-core-0.0.1-SNAPSHOT.jar
-goto endInit
-
-@REM Reaching here means variables are defined and arguments have been captured
-:endInit
-
-%JAVACMD% %JAVA_OPTS%  -classpath %CLASSPATH_PREFIX%;%CLASSPATH% -Dapp.name="pregelix" -Dapp.repo="%REPO%" -Dapp.home="%BASEDIR%" -Dbasedir="%BASEDIR%" org.apache.hadoop.util.RunJar %CMD_LINE_ARGS%
-if ERRORLEVEL 1 goto error
-goto end
-
-:error
-if "%OS%"=="Windows_NT" @endlocal
-set ERROR_CODE=%ERRORLEVEL%
-
-:end
-@REM set local scope for the variables with windows NT shell
-if "%OS%"=="Windows_NT" goto endNT
-
-@REM For old DOS remove the set variables from ENV - we assume they were not set
-@REM before we started - at least we don't leave any baggage around
-set CMD_LINE_ARGS=
-goto postExec
-
-:endNT
-@REM If error code is set to 1 then the endlocal was done already in :error.
-if %ERROR_CODE% EQU 0 @endlocal
-
-
-:postExec
-
-if "%FORCE_EXIT_ON_ERROR%" == "on" (
-  if %ERROR_CODE% NEQ 0 exit %ERROR_CODE%
-)
-
-exit /B %ERROR_CODE%
\ No newline at end of file
diff --git a/pregelix/pregelix-core/src/main/resources/scripts/pregelixcc b/pregelix/pregelix-core/src/main/resources/scripts/pregelixcc
deleted file mode 100755
index c1ee3f2..0000000
--- a/pregelix/pregelix-core/src/main/resources/scripts/pregelixcc
+++ /dev/null
@@ -1,114 +0,0 @@
-#!/bin/sh
-#
-#------------------------------------------------------------------------
-# Copyright 2009-2013 by The Regents of the University of California
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# you may obtain a copy of the License from
-# 
-#     http://www.apache.org/licenses/LICENSE-2.0
-# 
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-# ------------------------------------------------------------------------
-#
-
-# resolve links - $0 may be a softlink
-PRG="$0"
-
-while [ -h "$PRG" ]; do
-  ls=`ls -ld "$PRG"`
-  link=`expr "$ls" : '.*-> \(.*\)$'`
-  if expr "$link" : '/.*' > /dev/null; then
-    PRG="$link"
-  else
-    PRG=`dirname "$PRG"`/"$link"
-  fi
-done
-
-PRGDIR=`dirname "$PRG"`
-BASEDIR=`cd "$PRGDIR/.." >/dev/null; pwd`
-
-
-
-# OS specific support.  $var _must_ be set to either true or false.
-cygwin=false;
-darwin=false;
-case "`uname`" in
-  CYGWIN*) cygwin=true ;;
-  Darwin*) darwin=true
-           if [ -z "$JAVA_VERSION" ] ; then
-             JAVA_VERSION="CurrentJDK"
-           else
-             echo "Using Java version: $JAVA_VERSION"
-           fi
-           if [ -z "$JAVA_HOME" ] ; then
-             JAVA_HOME=/System/Library/Frameworks/JavaVM.framework/Versions/${JAVA_VERSION}/Home
-           fi
-           ;;
-esac
-
-if [ -z "$JAVA_HOME" ] ; then
-  if [ -r /etc/gentoo-release ] ; then
-    JAVA_HOME=`java-config --jre-home`
-  fi
-fi
-
-# For Cygwin, ensure paths are in UNIX format before anything is touched
-if $cygwin ; then
-  [ -n "$JAVA_HOME" ] && JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
-  [ -n "$CLASSPATH" ] && CLASSPATH=`cygpath --path --unix "$CLASSPATH"`
-fi
-
-# If a specific java binary isn't specified search for the standard 'java' binary
-if [ -z "$JAVACMD" ] ; then
-  if [ -n "$JAVA_HOME"  ] ; then
-    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
-      # IBM's JDK on AIX uses strange locations for the executables
-      JAVACMD="$JAVA_HOME/jre/sh/java"
-    else
-      JAVACMD="$JAVA_HOME/bin/java"
-    fi
-  else
-    JAVACMD=`which java`
-  fi
-fi
-
-if [ ! -x "$JAVACMD" ] ; then
-  echo "Error: JAVA_HOME is not defined correctly." 1>&2
-  echo "  We cannot execute $JAVACMD" 1>&2
-  exit 1
-fi
-
-if [ -z "$REPO" ]
-then
-  REPO="$BASEDIR"/lib
-fi
-
-CLASSPATH=$CLASSPATH_PREFIX:"$HADOOP_HOME"/conf:/etc/hadoop/conf:"$BASEDIR"/etc:$1
-
-for f in ${REPO}/*.jar; do
-  CLASSPATH=${CLASSPATH}:$f;
-done
-
-# For Cygwin, switch paths to Windows format before running java
-if $cygwin; then
-  [ -n "$CLASSPATH" ] && CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
-  [ -n "$JAVA_HOME" ] && JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"`
-  [ -n "$HOME" ] && HOME=`cygpath --path --windows "$HOME"`
-  [ -n "$BASEDIR" ] && BASEDIR=`cygpath --path --windows "$BASEDIR"`
-  [ -n "$REPO" ] && REPO=`cygpath --path --windows "$REPO"`
-fi
-
-exec "$JAVACMD" $JAVA_OPTS  \
-  -classpath "$CLASSPATH" \
-  -Dapp.name="pregelixcc" \
-  -Dapp.pid="$$" \
-  -Dapp.repo="$REPO" \
-  -Dapp.home="$BASEDIR" \
-  -Dbasedir="$BASEDIR" \
-  edu.uci.ics.hyracks.control.cc.CCDriver \
-  "$@"
diff --git a/pregelix/pregelix-core/src/main/resources/scripts/pregelixnc b/pregelix/pregelix-core/src/main/resources/scripts/pregelixnc
deleted file mode 100755
index c01b4b4..0000000
--- a/pregelix/pregelix-core/src/main/resources/scripts/pregelixnc
+++ /dev/null
@@ -1,115 +0,0 @@
-#!/bin/sh
-#
-#------------------------------------------------------------------------
-# Copyright 2009-2013 by The Regents of the University of California
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# you may obtain a copy of the License from
-# 
-#     http://www.apache.org/licenses/LICENSE-2.0
-# 
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-# ------------------------------------------------------------------------
-#
-
-# resolve links - $0 may be a softlink
-PRG="$0"
-
-while [ -h "$PRG" ]; do
-  ls=`ls -ld "$PRG"`
-  link=`expr "$ls" : '.*-> \(.*\)$'`
-  if expr "$link" : '/.*' > /dev/null; then
-    PRG="$link"
-  else
-    PRG=`dirname "$PRG"`/"$link"
-  fi
-done
-
-PRGDIR=`dirname "$PRG"`
-BASEDIR=`cd "$PRGDIR/.." >/dev/null; pwd`
-
-
-
-# OS specific support.  $var _must_ be set to either true or false.
-cygwin=false;
-darwin=false;
-case "`uname`" in
-  CYGWIN*) cygwin=true ;;
-  Darwin*) darwin=true
-           if [ -z "$JAVA_VERSION" ] ; then
-             JAVA_VERSION="CurrentJDK"
-           else
-             echo "Using Java version: $JAVA_VERSION"
-           fi
-           if [ -z "$JAVA_HOME" ] ; then
-             JAVA_HOME=/System/Library/Frameworks/JavaVM.framework/Versions/${JAVA_VERSION}/Home
-           fi
-           ;;
-esac
-
-if [ -z "$JAVA_HOME" ] ; then
-  if [ -r /etc/gentoo-release ] ; then
-    JAVA_HOME=`java-config --jre-home`
-  fi
-fi
-
-# For Cygwin, ensure paths are in UNIX format before anything is touched
-if $cygwin ; then
-  [ -n "$JAVA_HOME" ] && JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
-  [ -n "$CLASSPATH" ] && CLASSPATH=`cygpath --path --unix "$CLASSPATH"`
-fi
-
-# If a specific java binary isn't specified search for the standard 'java' binary
-if [ -z "$JAVACMD" ] ; then
-  if [ -n "$JAVA_HOME"  ] ; then
-    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
-      # IBM's JDK on AIX uses strange locations for the executables
-      JAVACMD="$JAVA_HOME/jre/sh/java"
-    else
-      JAVACMD="$JAVA_HOME/bin/java"
-    fi
-  else
-    JAVACMD=`which java`
-  fi
-fi
-
-if [ ! -x "$JAVACMD" ] ; then
-  echo "Error: JAVA_HOME is not defined correctly." 1>&2
-  echo "  We cannot execute $JAVACMD" 1>&2
-  exit 1
-fi
-
-if [ -z "$REPO" ]
-then
-  REPO="$BASEDIR"/lib
-fi
-
-CLASSPATH=$CLASSPATH_PREFIX:"$HADOOP_HOME"/conf:/etc/hadoop/conf:"$BASEDIR"/etc:$1
-
-for f in ${REPO}/*.jar; do
-  CLASSPATH=${CLASSPATH}:$f;
-done
-
-
-# For Cygwin, switch paths to Windows format before running java
-if $cygwin; then
-  [ -n "$CLASSPATH" ] && CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
-  [ -n "$JAVA_HOME" ] && JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"`
-  [ -n "$HOME" ] && HOME=`cygpath --path --windows "$HOME"`2
-  [ -n "$BASEDIR" ] && BASEDIR=`cygpath --path --windows "$BASEDIR"`
-  [ -n "$REPO" ] && REPO=`cygpath --path --windows "$REPO"`
-fi
-
-exec "$JAVACMD" $JAVA_OPTS  \
-  -classpath "$CLASSPATH" \
-  -Dapp.name="pregelixnc" \
-  -Dapp.pid="$$" \
-  -Dapp.repo="$REPO" \
-  -Dapp.home="$BASEDIR" \
-  -Dbasedir="$BASEDIR" \
-  edu.uci.ics.hyracks.control.nc.NCDriver \
-  -app-nc-main-class edu.uci.ics.pregelix.runtime.bootstrap.NCApplicationEntryPoint "$@"
diff --git a/pregelix/pregelix-core/src/main/resources/scripts/startcc.sh b/pregelix/pregelix-core/src/main/resources/scripts/startcc.sh
index 2a6cab2..d7a0ead 100644
--- a/pregelix/pregelix-core/src/main/resources/scripts/startcc.sh
+++ b/pregelix/pregelix-core/src/main/resources/scripts/startcc.sh
@@ -58,8 +58,8 @@
 
 if [ -f "conf/topology.xml"  ]; then
 #Launch hyracks cc script with topology
-${PREGELIX_HOME}/bin/pregelixcc -client-net-ip-address $CCHOST -cluster-net-ip-address $CCHOST -client-net-port $CC_CLIENTPORT -cluster-net-port $CC_CLUSTERPORT -max-heartbeat-lapse-periods 999999 -default-max-job-attempts 0 -job-history-size 0 -cluster-topology "conf/topology.xml" &> $CCLOGS_DIR/cc.log &
+${PREGELIX_HOME}/bin/pregelixcc -client-net-ip-address $CCHOST -cluster-net-ip-address $CCHOST -client-net-port $CC_CLIENTPORT -cluster-net-port $CC_CLUSTERPORT -heartbeat-period 5000 -max-heartbeat-lapse-periods 4 -default-max-job-attempts 0 -job-history-size 0 -cluster-topology "conf/topology.xml" &> $CCLOGS_DIR/cc.log &
 else
 #Launch hyracks cc script without toplogy
-${PREGELIX_HOME}/bin/pregelixcc -client-net-ip-address $CCHOST -cluster-net-ip-address $CCHOST -client-net-port $CC_CLIENTPORT -cluster-net-port $CC_CLUSTERPORT -max-heartbeat-lapse-periods 999999 -default-max-job-attempts 0 -job-history-size 0 &> $CCLOGS_DIR/cc.log &
+${PREGELIX_HOME}/bin/pregelixcc -client-net-ip-address $CCHOST -cluster-net-ip-address $CCHOST -client-net-port $CC_CLIENTPORT -cluster-net-port $CC_CLUSTERPORT -heartbeat-period 5000 -max-heartbeat-lapse-periods 4 -default-max-job-attempts 0 -job-history-size 0 &> $CCLOGS_DIR/cc.log &
 fi
diff --git a/pregelix/pregelix-dataflow-std-base/pom.xml b/pregelix/pregelix-dataflow-std-base/pom.xml
index 35a6c91..d4c0ee6 100644
--- a/pregelix/pregelix-dataflow-std-base/pom.xml
+++ b/pregelix/pregelix-dataflow-std-base/pom.xml
@@ -21,7 +21,7 @@
 	<parent>
     		<groupId>edu.uci.ics.hyracks</groupId>
     		<artifactId>pregelix</artifactId>
-    		<version>0.2.7-SNAPSHOT</version>
+    		<version>0.2.10-SNAPSHOT</version>
   	</parent>
 
 
@@ -87,15 +87,15 @@
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
-			<artifactId>pregelix-api</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<artifactId>hyracks-dataflow-common</artifactId>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-api</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
diff --git a/pregelix/pregelix-dataflow-std-base/src/main/java/edu/uci/ics/pregelix/dataflow/std/base/IAggregateFunction.java b/pregelix/pregelix-dataflow-std-base/src/main/java/edu/uci/ics/pregelix/dataflow/std/base/IAggregateFunction.java
index 97db63f..c544b31 100644
--- a/pregelix/pregelix-dataflow-std-base/src/main/java/edu/uci/ics/pregelix/dataflow/std/base/IAggregateFunction.java
+++ b/pregelix/pregelix-dataflow-std-base/src/main/java/edu/uci/ics/pregelix/dataflow/std/base/IAggregateFunction.java
@@ -24,4 +24,10 @@
     public void step(IFrameTupleReference tuple) throws HyracksDataException;
 
     public void finish() throws HyracksDataException;
+
+    public void initAll() throws HyracksDataException;
+
+    public void finishAll() throws HyracksDataException;
+
+    public int estimateStep(IFrameTupleReference tuple) throws HyracksDataException;
 }
diff --git a/pregelix/pregelix-dataflow-std-base/src/main/java/edu/uci/ics/pregelix/dataflow/std/base/IAggregateFunctionFactory.java b/pregelix/pregelix-dataflow-std-base/src/main/java/edu/uci/ics/pregelix/dataflow/std/base/IAggregateFunctionFactory.java
index 58795d1..d5364da 100644
--- a/pregelix/pregelix-dataflow-std-base/src/main/java/edu/uci/ics/pregelix/dataflow/std/base/IAggregateFunctionFactory.java
+++ b/pregelix/pregelix-dataflow-std-base/src/main/java/edu/uci/ics/pregelix/dataflow/std/base/IAggregateFunctionFactory.java
@@ -16,11 +16,12 @@
 
 import java.io.Serializable;
 
+import edu.uci.ics.hyracks.api.comm.IFrameWriter;
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 import edu.uci.ics.hyracks.data.std.api.IDataOutputProvider;
 
 public interface IAggregateFunctionFactory extends Serializable {
-	public IAggregateFunction createAggregateFunction(IHyracksTaskContext ctx,
-			IDataOutputProvider provider) throws HyracksException;
+    public IAggregateFunction createAggregateFunction(IHyracksTaskContext ctx, IDataOutputProvider provider,
+            IFrameWriter writer) throws HyracksException;
 }
\ No newline at end of file
diff --git a/pregelix/pregelix-dataflow-std/pom.xml b/pregelix/pregelix-dataflow-std/pom.xml
index 3604e57..9ec8e1d 100644
--- a/pregelix/pregelix-dataflow-std/pom.xml
+++ b/pregelix/pregelix-dataflow-std/pom.xml
@@ -21,7 +21,7 @@
 	<parent>
 		<groupId>edu.uci.ics.hyracks</groupId>
 		<artifactId>pregelix</artifactId>
-		<version>0.2.7-SNAPSHOT</version>
+		<version>0.2.10-SNAPSHOT</version>
 	</parent>
 
 
@@ -88,84 +88,84 @@
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>pregelix-dataflow-std-base</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-dataflow-std</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-api</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-dataflow-common</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-data-std</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-hdfs-core</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-storage-am-common</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-storage-am-btree</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-storage-am-lsm-btree</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-control-cc</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-control-nc</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-ipc</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
diff --git a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/group/ClusteredGroupOperatorDescriptor.java b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/group/ClusteredGroupOperatorDescriptor.java
new file mode 100644
index 0000000..bb41953
--- /dev/null
+++ b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/group/ClusteredGroupOperatorDescriptor.java
@@ -0,0 +1,50 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.dataflow.group;
+
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
+import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
+import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
+import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.job.IOperatorDescriptorRegistry;
+import edu.uci.ics.hyracks.dataflow.std.base.AbstractSingleActivityOperatorDescriptor;
+
+public class ClusteredGroupOperatorDescriptor extends AbstractSingleActivityOperatorDescriptor {
+    private final int[] groupFields;
+    private final IBinaryComparatorFactory[] comparatorFactories;
+    private final IClusteredAggregatorDescriptorFactory aggregatorFactory;
+
+    private static final long serialVersionUID = 1L;
+
+    public ClusteredGroupOperatorDescriptor(IOperatorDescriptorRegistry spec, int[] groupFields,
+            IBinaryComparatorFactory[] comparatorFactories, IClusteredAggregatorDescriptorFactory aggregatorFactory,
+            RecordDescriptor recordDescriptor) {
+        super(spec, 1, 1);
+        this.groupFields = groupFields;
+        this.comparatorFactories = comparatorFactories;
+        this.aggregatorFactory = aggregatorFactory;
+        recordDescriptors[0] = recordDescriptor;
+    }
+
+    @Override
+    public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx,
+            final IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions)
+            throws HyracksDataException {
+        return new ClusteredGroupOperatorNodePushable(ctx, groupFields, comparatorFactories, aggregatorFactory,
+                recordDescProvider.getInputRecordDescriptor(getActivityId(), 0), recordDescriptors[0]);
+    }
+}
\ No newline at end of file
diff --git a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/group/ClusteredGroupOperatorNodePushable.java b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/group/ClusteredGroupOperatorNodePushable.java
new file mode 100644
index 0000000..a95a46e
--- /dev/null
+++ b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/group/ClusteredGroupOperatorNodePushable.java
@@ -0,0 +1,79 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.dataflow.group;
+
+import java.nio.ByteBuffer;
+
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparator;
+import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
+import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAccessor;
+import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAppender;
+import edu.uci.ics.hyracks.dataflow.std.base.AbstractUnaryInputUnaryOutputOperatorNodePushable;
+
+class ClusteredGroupOperatorNodePushable extends AbstractUnaryInputUnaryOutputOperatorNodePushable {
+    private final IHyracksTaskContext ctx;
+    private final int[] groupFields;
+    private final IBinaryComparatorFactory[] comparatorFactories;
+    private final IClusteredAggregatorDescriptorFactory aggregatorFactory;
+    private final RecordDescriptor inRecordDescriptor;
+    private final RecordDescriptor outRecordDescriptor;
+    private ClusteredGroupWriter pgw;
+
+    ClusteredGroupOperatorNodePushable(IHyracksTaskContext ctx, int[] groupFields,
+            IBinaryComparatorFactory[] comparatorFactories, IClusteredAggregatorDescriptorFactory aggregatorFactory,
+            RecordDescriptor inRecordDescriptor, RecordDescriptor outRecordDescriptor) {
+        this.ctx = ctx;
+        this.groupFields = groupFields;
+        this.comparatorFactories = comparatorFactories;
+        this.aggregatorFactory = aggregatorFactory;
+        this.inRecordDescriptor = inRecordDescriptor;
+        this.outRecordDescriptor = outRecordDescriptor;
+    }
+
+    @Override
+    public void open() throws HyracksDataException {
+        final IBinaryComparator[] comparators = new IBinaryComparator[comparatorFactories.length];
+        for (int i = 0; i < comparatorFactories.length; ++i) {
+            comparators[i] = comparatorFactories[i].createBinaryComparator();
+        }
+        final ByteBuffer copyFrame = ctx.allocateFrame();
+        final FrameTupleAccessor copyFrameAccessor = new FrameTupleAccessor(ctx.getFrameSize(), inRecordDescriptor);
+        copyFrameAccessor.reset(copyFrame);
+        ByteBuffer outFrame = ctx.allocateFrame();
+        final FrameTupleAppender appender = new FrameTupleAppender(ctx.getFrameSize());
+        appender.reset(outFrame, true);
+        pgw = new ClusteredGroupWriter(ctx, groupFields, comparators, aggregatorFactory, inRecordDescriptor,
+                outRecordDescriptor, writer);
+        pgw.open();
+    }
+
+    @Override
+    public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
+        pgw.nextFrame(buffer);
+    }
+
+    @Override
+    public void fail() throws HyracksDataException {
+        pgw.fail();
+    }
+
+    @Override
+    public void close() throws HyracksDataException {
+        pgw.close();
+    }
+}
\ No newline at end of file
diff --git a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/group/ClusteredGroupWriter.java b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/group/ClusteredGroupWriter.java
new file mode 100644
index 0000000..4b4a1c3
--- /dev/null
+++ b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/group/ClusteredGroupWriter.java
@@ -0,0 +1,165 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.dataflow.group;
+
+import java.nio.ByteBuffer;
+
+import edu.uci.ics.hyracks.api.comm.IFrameWriter;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparator;
+import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
+import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAccessor;
+import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAppender;
+import edu.uci.ics.hyracks.dataflow.common.comm.util.FrameUtils;
+import edu.uci.ics.hyracks.dataflow.std.group.AggregateState;
+import edu.uci.ics.hyracks.dataflow.std.group.IAggregatorDescriptor;
+
+public class ClusteredGroupWriter implements IFrameWriter {
+    private final int[] groupFields;
+    private final IBinaryComparator[] comparators;
+    private final IAggregatorDescriptor aggregator;
+    private final AggregateState aggregateState;
+    private final IFrameWriter writer;
+    private final ByteBuffer copyFrame;
+    private final FrameTupleAccessor inFrameAccessor;
+    private final FrameTupleAccessor copyFrameAccessor;
+
+    private final ByteBuffer outFrame;
+    private final FrameTupleAppender appender;
+    private final ArrayTupleBuilder tupleBuilder;
+
+    private boolean first;
+
+    public ClusteredGroupWriter(IHyracksTaskContext ctx, int[] groupFields, IBinaryComparator[] comparators,
+            IClusteredAggregatorDescriptorFactory aggregatorFactory, RecordDescriptor inRecordDesc,
+            RecordDescriptor outRecordDesc, IFrameWriter writer) throws HyracksDataException {
+        this.groupFields = groupFields;
+        this.comparators = comparators;
+        this.writer = writer;
+        copyFrame = ctx.allocateFrame();
+        inFrameAccessor = new FrameTupleAccessor(ctx.getFrameSize(), inRecordDesc);
+        copyFrameAccessor = new FrameTupleAccessor(ctx.getFrameSize(), inRecordDesc);
+        copyFrameAccessor.reset(copyFrame);
+
+        outFrame = ctx.allocateFrame();
+        appender = new FrameTupleAppender(ctx.getFrameSize());
+        appender.reset(outFrame, true);
+
+        tupleBuilder = new ArrayTupleBuilder(outRecordDesc.getFields().length);
+        this.aggregator = aggregatorFactory.createAggregator(ctx, inRecordDesc, outRecordDesc, groupFields, groupFields, writer, outFrame, appender);
+        this.aggregateState = aggregator.createAggregateStates();
+    }
+
+    @Override
+    public void open() throws HyracksDataException {
+        writer.open();
+        first = true;
+    }
+
+    @Override
+    public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
+        inFrameAccessor.reset(buffer);
+        int nTuples = inFrameAccessor.getTupleCount();
+        for (int i = 0; i < nTuples; ++i) {
+            if (first) {
+
+                tupleBuilder.reset();
+                for (int j = 0; j < groupFields.length; j++) {
+                    tupleBuilder.addField(inFrameAccessor, i, groupFields[j]);
+                }
+                aggregator.init(tupleBuilder, inFrameAccessor, i, aggregateState);
+
+                first = false;
+
+            } else {
+                if (i == 0) {
+                    switchGroupIfRequired(copyFrameAccessor, copyFrameAccessor.getTupleCount() - 1, inFrameAccessor, i);
+                } else {
+                    switchGroupIfRequired(inFrameAccessor, i - 1, inFrameAccessor, i);
+                }
+
+            }
+        }
+        FrameUtils.copy(buffer, copyFrame);
+    }
+
+    private void switchGroupIfRequired(FrameTupleAccessor prevTupleAccessor, int prevTupleIndex,
+            FrameTupleAccessor currTupleAccessor, int currTupleIndex) throws HyracksDataException {
+        if (!sameGroup(prevTupleAccessor, prevTupleIndex, currTupleAccessor, currTupleIndex)) {
+            writeOutput(prevTupleAccessor, prevTupleIndex);
+
+            tupleBuilder.reset();
+            for (int j = 0; j < groupFields.length; j++) {
+                tupleBuilder.addField(currTupleAccessor, currTupleIndex, groupFields[j]);
+            }
+            aggregator.init(tupleBuilder, currTupleAccessor, currTupleIndex, aggregateState);
+        } else {
+            aggregator.aggregate(currTupleAccessor, currTupleIndex, null, 0, aggregateState);
+        }
+    }
+
+    private void writeOutput(final FrameTupleAccessor lastTupleAccessor, int lastTupleIndex)
+            throws HyracksDataException {
+        tupleBuilder.reset();
+        for (int j = 0; j < groupFields.length; j++) {
+            tupleBuilder.addField(lastTupleAccessor, lastTupleIndex, groupFields[j]);
+        }
+        aggregator.outputFinalResult(tupleBuilder, lastTupleAccessor, lastTupleIndex, aggregateState);
+        if (!appender.appendSkipEmptyField(tupleBuilder.getFieldEndOffsets(), tupleBuilder.getByteArray(), 0,
+                tupleBuilder.getSize())) {
+            FrameUtils.flushFrame(outFrame, writer);
+            appender.reset(outFrame, true);
+            if (!appender.appendSkipEmptyField(tupleBuilder.getFieldEndOffsets(), tupleBuilder.getByteArray(), 0,
+                    tupleBuilder.getSize())) {
+                throw new HyracksDataException("The output of size " + tupleBuilder.getSize()
+                        + " cannot be fit into a frame of size " + outFrame.array().length);
+            }
+        }
+
+    }
+
+    private boolean sameGroup(FrameTupleAccessor a1, int t1Idx, FrameTupleAccessor a2, int t2Idx) {
+        for (int i = 0; i < comparators.length; ++i) {
+            int fIdx = groupFields[i];
+            int s1 = a1.getTupleStartOffset(t1Idx) + a1.getFieldSlotsLength() + a1.getFieldStartOffset(t1Idx, fIdx);
+            int l1 = a1.getFieldLength(t1Idx, fIdx);
+            int s2 = a2.getTupleStartOffset(t2Idx) + a2.getFieldSlotsLength() + a2.getFieldStartOffset(t2Idx, fIdx);
+            int l2 = a2.getFieldLength(t2Idx, fIdx);
+            if (comparators[i].compare(a1.getBuffer().array(), s1, l1, a2.getBuffer().array(), s2, l2) != 0) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    @Override
+    public void fail() throws HyracksDataException {
+        writer.fail();
+    }
+
+    @Override
+    public void close() throws HyracksDataException {
+        if (!first) {
+            writeOutput(copyFrameAccessor, copyFrameAccessor.getTupleCount() - 1);
+            if (appender.getTupleCount() > 0) {
+                FrameUtils.flushFrame(outFrame, writer);
+            }
+        }
+        aggregateState.close();
+        writer.close();
+    }
+}
\ No newline at end of file
diff --git a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/group/IClusteredAggregatorDescriptorFactory.java b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/group/IClusteredAggregatorDescriptorFactory.java
new file mode 100644
index 0000000..3256f08
--- /dev/null
+++ b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/group/IClusteredAggregatorDescriptorFactory.java
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.dataflow.group;
+
+import java.io.Serializable;
+import java.nio.ByteBuffer;
+
+import edu.uci.ics.hyracks.api.comm.IFrameWriter;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAppender;
+import edu.uci.ics.hyracks.dataflow.std.group.IAggregatorDescriptor;
+
+/**
+ *
+ */
+public interface IClusteredAggregatorDescriptorFactory extends Serializable {
+
+    IAggregatorDescriptor createAggregator(IHyracksTaskContext ctx, RecordDescriptor inRecordDescriptor,
+            RecordDescriptor outRecordDescriptor, int[] keyFields, final int[] keyFieldsInPartialResults,
+            IFrameWriter resultWriter, ByteBuffer outputFrame, FrameTupleAppender appender) throws HyracksDataException;
+
+}
diff --git a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/IndexNestedLoopJoinFunctionUpdateOperatorNodePushable.java b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/IndexNestedLoopJoinFunctionUpdateOperatorNodePushable.java
index 5156dbf..b22e468 100644
--- a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/IndexNestedLoopJoinFunctionUpdateOperatorNodePushable.java
+++ b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/IndexNestedLoopJoinFunctionUpdateOperatorNodePushable.java
@@ -157,16 +157,34 @@
             ITupleReference tupleRef = cursor.getTuple();
 
             /**
+             * merge with updated tuple
+             */
+            ITupleReference indexEntryTuple = tupleRef;
+            ITupleReference cachedUpdatedLastTuple = updateBuffer.getLastTuple();
+            if (cachedUpdatedLastTuple != null) {
+                if (compare(cachedUpdatedLastTuple, tupleRef) == 0) {
+                    indexEntryTuple = cachedUpdatedLastTuple;
+                }
+            }
+
+            /**
              * call the update function
              */
-            functionProxy.functionCall(leftAccessor, tIndex, tupleRef, cloneUpdateTb);
+            functionProxy.functionCall(leftAccessor, tIndex, indexEntryTuple, cloneUpdateTb);
 
-            //doing copy update
-            CopyUpdateUtil.copyUpdate(tempTupleReference, tupleRef, updateBuffer, cloneUpdateTb, indexAccessor, cursor,
-                    rangePred);
+            /**
+             * doing copy update
+             */
+            CopyUpdateUtil.copyUpdate(tempTupleReference, indexEntryTuple, updateBuffer, cloneUpdateTb, indexAccessor,
+                    cursor, rangePred);
         }
     }
 
+    /** compare tuples */
+    private int compare(ITupleReference left, ITupleReference right) throws Exception {
+        return lowKeySearchCmp.compare(left, right);
+    }
+
     @Override
     public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
         accessor.reset(buffer);
@@ -212,8 +230,16 @@
 
     @Override
     public void fail() throws HyracksDataException {
-        for (IFrameWriter writer : writers)
+        try {
+            cursor.close();
+        } catch (Exception e) {
+            throw new HyracksDataException(e);
+        } finally {
+            treeIndexOpHelper.close();
+        }
+        for (IFrameWriter writer : writers) {
             writer.fail();
+        }
     }
 
     @Override
diff --git a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/IndexNestedLoopRightOuterJoinFunctionUpdateOperatorNodePushable.java b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/IndexNestedLoopRightOuterJoinFunctionUpdateOperatorNodePushable.java
index 4ca7533..0ecfd03 100644
--- a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/IndexNestedLoopRightOuterJoinFunctionUpdateOperatorNodePushable.java
+++ b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/IndexNestedLoopRightOuterJoinFunctionUpdateOperatorNodePushable.java
@@ -195,8 +195,10 @@
                 // TODO: currently use low key only, check what they mean
                 int cmp = compare(lowKey, currentTopTuple);
                 if (cmp <= 0) {
-                    if (cmp == 0)
+                    if (cmp == 0) {
                         outputMatch(i);
+                        currentTopTuple = cursor.getTuple();
+                    }
                     i++;
                 } else {
                     moveTreeCursor();
@@ -252,8 +254,16 @@
 
     @Override
     public void fail() throws HyracksDataException {
-        for (IFrameWriter writer : writers)
+        try {
+            cursor.close();
+        } catch (Exception e) {
+            throw new HyracksDataException(e);
+        } finally {
+            treeIndexOpHelper.close();
+        }
+        for (IFrameWriter writer : writers) {
             writer.fail();
+        }
     }
 
     /** compare tuples */
@@ -262,16 +272,28 @@
     }
 
     //for the join match casesos
-    private void writeResults(IFrameTupleAccessor leftAccessor, int tIndex, ITupleReference frameTuple)
+    private void writeResults(IFrameTupleAccessor leftAccessor, int tIndex, ITupleReference indexTuple)
             throws Exception {
         /**
+         * merge with the cached tuple, if any
+         */
+        ITupleReference indexEntryTuple = indexTuple;
+        ITupleReference cachedUpdatedLastTuple = updateBuffer.getLastTuple();
+        if (cachedUpdatedLastTuple != null) {
+            if (compare(cachedUpdatedLastTuple, indexTuple) == 0) {
+                indexEntryTuple = cachedUpdatedLastTuple;
+            }
+        }
+        /**
          * function call
          */
-        functionProxy.functionCall(leftAccessor, tIndex, frameTuple, cloneUpdateTb);
+        functionProxy.functionCall(leftAccessor, tIndex, indexEntryTuple, cloneUpdateTb);
 
-        //doing clone update
-        CopyUpdateUtil.copyUpdate(tempTupleReference, frameTuple, updateBuffer, cloneUpdateTb, indexAccessor, cursor,
-                rangePred);
+        /**
+         * doing clone update
+         */
+        CopyUpdateUtil.copyUpdate(tempTupleReference, indexEntryTuple, updateBuffer, cloneUpdateTb, indexAccessor,
+                cursor, rangePred);
     }
 
     /** write result for outer case */
@@ -290,4 +312,4 @@
     public void setOutputFrameWriter(int index, IFrameWriter writer, RecordDescriptor recordDesc) {
         writers[index] = writer;
     }
-}
\ No newline at end of file
+}
diff --git a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/IndexNestedLoopRightOuterJoinOperatorNodePushable.java b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/IndexNestedLoopRightOuterJoinOperatorNodePushable.java
index dd6ee3c..e64e9cc 100644
--- a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/IndexNestedLoopRightOuterJoinOperatorNodePushable.java
+++ b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/IndexNestedLoopRightOuterJoinOperatorNodePushable.java
@@ -245,6 +245,13 @@
 
     @Override
     public void fail() throws HyracksDataException {
+        try {
+            cursor.close();
+        } catch (Exception e) {
+            throw new HyracksDataException(e);
+        } finally {
+            treeIndexOpHelper.close();
+        }
         writer.fail();
     }
 
diff --git a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/IndexNestedLoopSetUnionFunctionUpdateOperatorNodePushable.java b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/IndexNestedLoopSetUnionFunctionUpdateOperatorNodePushable.java
index 3cebfb8..a9c787f 100644
--- a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/IndexNestedLoopSetUnionFunctionUpdateOperatorNodePushable.java
+++ b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/IndexNestedLoopSetUnionFunctionUpdateOperatorNodePushable.java
@@ -219,8 +219,16 @@
 
     @Override
     public void fail() throws HyracksDataException {
-        for (IFrameWriter writer : writers)
+        try {
+            cursor.close();
+        } catch (Exception e) {
+            throw new HyracksDataException(e);
+        } finally {
+            treeIndexOpHelper.close();
+        }
+        for (IFrameWriter writer : writers) {
             writer.fail();
+        }
     }
 
     /** compare tuples */
diff --git a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/IndexNestedLoopSetUnionOperatorNodePushable.java b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/IndexNestedLoopSetUnionOperatorNodePushable.java
index bbe2764..86a211f 100644
--- a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/IndexNestedLoopSetUnionOperatorNodePushable.java
+++ b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/IndexNestedLoopSetUnionOperatorNodePushable.java
@@ -205,6 +205,13 @@
 
     @Override
     public void fail() throws HyracksDataException {
+        try {
+            cursor.close();
+        } catch (Exception e) {
+            throw new HyracksDataException(e);
+        } finally {
+            treeIndexOpHelper.close();
+        }
         writer.fail();
     }
 
diff --git a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/TreeIndexBulkReLoadOperatorNodePushable.java b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/TreeIndexBulkReLoadOperatorNodePushable.java
index c4890e1..c985f64 100644
--- a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/TreeIndexBulkReLoadOperatorNodePushable.java
+++ b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/TreeIndexBulkReLoadOperatorNodePushable.java
@@ -100,6 +100,11 @@
 
     @Override
     public void fail() throws HyracksDataException {
-
+        try {
+            bulkLoader.end();
+        } catch (IndexException e) {
+            treeIndexOpHelper.close();
+            throw new HyracksDataException(e);
+        } 
     }
 }
\ No newline at end of file
diff --git a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/TreeSearchFunctionUpdateOperatorNodePushable.java b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/TreeSearchFunctionUpdateOperatorNodePushable.java
index bd85e3e..de87909 100644
--- a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/TreeSearchFunctionUpdateOperatorNodePushable.java
+++ b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/TreeSearchFunctionUpdateOperatorNodePushable.java
@@ -224,8 +224,16 @@
 
     @Override
     public void fail() throws HyracksDataException {
-        for (IFrameWriter writer : writers)
+        try {
+            cursor.close();
+        } catch (Exception e) {
+            throw new HyracksDataException(e);
+        } finally {
+            treeIndexHelper.close();
+        }
+        for (IFrameWriter writer : writers) {
             writer.fail();
+        }
     }
 
     @Override
diff --git a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/CopyUpdateUtil.java b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/CopyUpdateUtil.java
index 8709301..392f728 100644
--- a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/CopyUpdateUtil.java
+++ b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/CopyUpdateUtil.java
@@ -34,7 +34,7 @@
             int srcLen = fieldEndOffsets[1] - fieldEndOffsets[0]; // the updated vertex size
             int frSize = frameTuple.getFieldLength(1); // the vertex binary size in the leaf page
             if (srcLen <= frSize) {
-                //doing in-place update if possible, save the "real update" overhead
+                //doing in-place update if the vertex size is not larger than the original size, save the "real update" overhead
                 System.arraycopy(cloneUpdateTb.getByteArray(), srcStart, frameTuple.getFieldData(1),
                         frameTuple.getFieldStart(1), srcLen);
                 cloneUpdateTb.reset();
diff --git a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/ResetableByteArrayInputStream.java b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/ResetableByteArrayInputStream.java
index b697466..5be9ffc 100644
--- a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/ResetableByteArrayInputStream.java
+++ b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/ResetableByteArrayInputStream.java
@@ -15,11 +15,8 @@
 package edu.uci.ics.pregelix.dataflow.util;
 
 import java.io.InputStream;
-import java.util.logging.Level;
-import java.util.logging.Logger;
 
 public class ResetableByteArrayInputStream extends InputStream {
-    private static final Logger LOGGER = Logger.getLogger(ResetableByteArrayInputStream.class.getName());
 
     private byte[] data;
     private int position;
@@ -36,19 +33,12 @@
     public int read() {
         int remaining = data.length - position;
         int value = remaining > 0 ? (data[position++] & 0xff) : -1;
-        if (LOGGER.isLoggable(Level.FINEST)) {
-            LOGGER.finest("read(): value: " + value + " remaining: " + remaining + " position: " + position);
-        }
         return value;
     }
 
     @Override
     public int read(byte[] bytes, int offset, int length) {
         int remaining = data.length - position;
-        if (LOGGER.isLoggable(Level.FINEST)) {
-            LOGGER.finest("read(bytes[], int, int): remaining: " + remaining + " offset: " + offset + " length: "
-                    + length + " position: " + position);
-        }
         if (remaining == 0) {
             return -1;
         }
@@ -57,4 +47,9 @@
         position += l;
         return l;
     }
+
+    @Override
+    public int available() {
+        return data.length - position;
+    }
 }
\ No newline at end of file
diff --git a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/TupleDeserializer.java b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/TupleDeserializer.java
index 150bd8b..2fa1a4b 100644
--- a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/TupleDeserializer.java
+++ b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/TupleDeserializer.java
@@ -17,19 +17,15 @@
 
 import java.io.DataInputStream;
 import java.io.IOException;
-import java.util.logging.Level;
-import java.util.logging.Logger;
 
 import edu.uci.ics.hyracks.api.comm.IFrameTupleAccessor;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
-import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameConstants;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
 
 public class TupleDeserializer {
-    private static final Logger LOGGER = Logger.getLogger(TupleDeserializer.class.getName());
-
+    private static String ERROR_MSG = "Out-of-bound read in your Writable implementations of types for vertex id, vertex value, edge value or message --- check your readFields and write implmenetation";
     private Object[] record;
     private RecordDescriptor recordDescriptor;
     private ResetableByteArrayInputStream bbis;
@@ -43,132 +39,120 @@
     }
 
     public Object[] deserializeRecord(ITupleReference tupleRef) throws HyracksDataException {
-        for (int i = 0; i < tupleRef.getFieldCount(); ++i) {
-            byte[] data = tupleRef.getFieldData(i);
-            int offset = tupleRef.getFieldStart(i);
-            bbis.setByteArray(data, offset);
+        try {
+            for (int i = 0; i < tupleRef.getFieldCount(); ++i) {
+                byte[] data = tupleRef.getFieldData(i);
+                int offset = tupleRef.getFieldStart(i);
+                int len = tupleRef.getFieldLength(i);
+                bbis.setByteArray(data, offset);
 
-            Object instance = recordDescriptor.getFields()[i].deserialize(di);
-            if (LOGGER.isLoggable(Level.FINEST)) {
-                LOGGER.finest(i + " " + instance);
-            }
-            record[i] = instance;
-            if (FrameConstants.DEBUG_FRAME_IO) {
-                try {
-                    if (di.readInt() != FrameConstants.FRAME_FIELD_MAGIC) {
-                        throw new HyracksDataException("Field magic mismatch");
-                    }
-                } catch (IOException e) {
-                    e.printStackTrace();
+                int availableBefore = bbis.available();
+                Object instance = recordDescriptor.getFields()[i].deserialize(di);
+                int availableAfter = bbis.available();
+                if (availableBefore - availableAfter > len) {
+                    throw new IllegalStateException(ERROR_MSG);
                 }
+
+                record[i] = instance;
             }
+            return record;
+        } catch (IOException e) {
+            throw new HyracksDataException(e);
         }
-        return record;
     }
 
     public Object[] deserializeRecord(IFrameTupleAccessor left, int tIndex, ITupleReference right)
             throws HyracksDataException {
-        byte[] data = left.getBuffer().array();
-        int tStart = left.getTupleStartOffset(tIndex) + left.getFieldSlotsLength();
-        int leftFieldCount = left.getFieldCount();
-        int fStart = tStart;
-        for (int i = 0; i < leftFieldCount; ++i) {
-            /**
-             * reset the input
-             */
-            fStart = tStart + left.getFieldStartOffset(tIndex, i);
-            bbis.setByteArray(data, fStart);
+        try {
+            /** skip vertex id field in deserialization */
+            byte[] data = left.getBuffer().array();
+            int tStart = left.getTupleStartOffset(tIndex) + left.getFieldSlotsLength();
+            int leftFieldCount = left.getFieldCount();
+            int fStart = tStart;
+            for (int i = 1; i < leftFieldCount; ++i) {
+                /**
+                 * reset the input
+                 */
+                fStart = tStart + left.getFieldStartOffset(tIndex, i);
+                int fieldLength = left.getFieldLength(tIndex, i);
+                bbis.setByteArray(data, fStart);
 
-            /**
-             * do deserialization
-             */
-            Object instance = recordDescriptor.getFields()[i].deserialize(di);
-            if (LOGGER.isLoggable(Level.FINEST)) {
-                LOGGER.finest(i + " " + instance);
-            }
-            record[i] = instance;
-            if (FrameConstants.DEBUG_FRAME_IO) {
-                try {
-                    if (di.readInt() != FrameConstants.FRAME_FIELD_MAGIC) {
-                        throw new HyracksDataException("Field magic mismatch");
-                    }
-                } catch (IOException e) {
-                    e.printStackTrace();
-                }
-            }
-        }
-        for (int i = leftFieldCount; i < record.length; ++i) {
-            byte[] rightData = right.getFieldData(i - leftFieldCount);
-            int rightOffset = right.getFieldStart(i - leftFieldCount);
-            bbis.setByteArray(rightData, rightOffset);
+                /**
+                 * do deserialization
+                 */
+                int availableBefore = bbis.available();
+                Object instance = recordDescriptor.getFields()[i].deserialize(di);
+                int availableAfter = bbis.available();
+                if (availableBefore - availableAfter > fieldLength) {
+                    throw new IllegalStateException(ERROR_MSG);
 
-            Object instance = recordDescriptor.getFields()[i].deserialize(di);
-            if (LOGGER.isLoggable(Level.FINEST)) {
-                LOGGER.finest(i + " " + instance);
-            }
-            record[i] = instance;
-            if (FrameConstants.DEBUG_FRAME_IO) {
-                try {
-                    if (di.readInt() != FrameConstants.FRAME_FIELD_MAGIC) {
-                        throw new HyracksDataException("Field magic mismatch");
-                    }
-                } catch (IOException e) {
-                    e.printStackTrace();
                 }
+                record[i] = instance;
             }
+            /** skip vertex id field in deserialization */
+            for (int i = leftFieldCount + 1; i < record.length; ++i) {
+                byte[] rightData = right.getFieldData(i - leftFieldCount);
+                int rightOffset = right.getFieldStart(i - leftFieldCount);
+                int len = right.getFieldLength(i - leftFieldCount);
+                bbis.setByteArray(rightData, rightOffset);
+
+                int availableBefore = bbis.available();
+                Object instance = recordDescriptor.getFields()[i].deserialize(di);
+                int availableAfter = bbis.available();
+                if (availableBefore - availableAfter > len) {
+                    throw new IllegalStateException(ERROR_MSG);
+                }
+                record[i] = instance;
+            }
+            return record;
+        } catch (IOException e) {
+            throw new HyracksDataException(e);
         }
-        return record;
     }
 
     public Object[] deserializeRecord(ArrayTupleBuilder tb, ITupleReference right) throws HyracksDataException {
-        byte[] data = tb.getByteArray();
-        int[] offset = tb.getFieldEndOffsets();
-        int start = 0;
-        for (int i = 0; i < offset.length; ++i) {
-            /**
-             * reset the input
-             */
-            bbis.setByteArray(data, start);
-            start = offset[i];
+        try {
+            byte[] data = tb.getByteArray();
+            int[] offset = tb.getFieldEndOffsets();
+            int start = 0;
+            /** skip vertex id fields in deserialization */
+            for (int i = 1; i < offset.length; ++i) {
+                /**
+                 * reset the input
+                 */
+                start = offset[i - 1];
+                bbis.setByteArray(data, start);
+                int fieldLength = i == 0 ? offset[0] : offset[i] - offset[i - 1];
 
-            /**
-             * do deserialization
-             */
-            Object instance = recordDescriptor.getFields()[i].deserialize(di);
-            if (LOGGER.isLoggable(Level.FINEST)) {
-                LOGGER.finest(i + " " + instance);
-            }
-            record[i] = instance;
-            if (FrameConstants.DEBUG_FRAME_IO) {
-                try {
-                    if (di.readInt() != FrameConstants.FRAME_FIELD_MAGIC) {
-                        throw new HyracksDataException("Field magic mismatch");
-                    }
-                } catch (IOException e) {
-                    e.printStackTrace();
+                /**
+                 * do deserialization
+                 */
+                int availableBefore = bbis.available();
+                Object instance = recordDescriptor.getFields()[i].deserialize(di);
+                int availableAfter = bbis.available();
+                if (availableBefore - availableAfter > fieldLength) {
+                    throw new IllegalStateException(ERROR_MSG);
                 }
+                record[i] = instance;
             }
-        }
-        for (int i = offset.length; i < record.length; ++i) {
-            byte[] rightData = right.getFieldData(i - offset.length);
-            int rightOffset = right.getFieldStart(i - offset.length);
-            bbis.setByteArray(rightData, rightOffset);
+            /** skip vertex id fields in deserialization */
+            for (int i = offset.length + 1; i < record.length; ++i) {
+                byte[] rightData = right.getFieldData(i - offset.length);
+                int rightOffset = right.getFieldStart(i - offset.length);
+                bbis.setByteArray(rightData, rightOffset);
+                int fieldLength = right.getFieldLength(i - offset.length);
 
-            Object instance = recordDescriptor.getFields()[i].deserialize(di);
-            if (LOGGER.isLoggable(Level.FINEST)) {
-                LOGGER.finest(i + " " + instance);
-            }
-            record[i] = instance;
-            if (FrameConstants.DEBUG_FRAME_IO) {
-                try {
-                    if (di.readInt() != FrameConstants.FRAME_FIELD_MAGIC) {
-                        throw new HyracksDataException("Field magic mismatch");
-                    }
-                } catch (IOException e) {
-                    e.printStackTrace();
+                int availableBefore = bbis.available();
+                Object instance = recordDescriptor.getFields()[i].deserialize(di);
+                int availableAfter = bbis.available();
+                if (availableBefore - availableAfter > fieldLength) {
+                    throw new IllegalStateException(ERROR_MSG);
                 }
+                record[i] = instance;
             }
+            return record;
+        } catch (IOException e) {
+            throw new HyracksDataException(e);
         }
-        return record;
     }
 }
diff --git a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/UpdateBuffer.java b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/UpdateBuffer.java
index b2be366..4421695 100644
--- a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/UpdateBuffer.java
+++ b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/UpdateBuffer.java
@@ -25,8 +25,10 @@
 import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAppender;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.FrameTupleReference;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.am.common.exceptions.TreeIndexNonExistentKeyException;
 
 /**
  * The buffer to hold updates.
@@ -41,6 +43,7 @@
     private final FrameTupleAppender appender;
     private final IHyracksTaskContext ctx;
     private final FrameTupleReference tuple = new FrameTupleReference();
+    private final FrameTupleReference lastTuple = new FrameTupleReference();
     private final int frameSize;
     private IFrameTupleAccessor fta;
 
@@ -94,7 +97,12 @@
             fta.reset(buffer);
             for (int j = 0; j < fta.getTupleCount(); j++) {
                 tuple.reset(fta, j);
-                bta.update(tuple);
+                try {
+                    bta.update(tuple);
+                } catch (TreeIndexNonExistentKeyException e) {
+                    // ignore non-existent key exception
+                    bta.insert(tuple);
+                }
             }
         }
 
@@ -104,6 +112,21 @@
         appender.reset(buffer, true);
     }
 
+    /**
+     * return the last updated
+     * 
+     * @throws HyracksDataException
+     */
+    public ITupleReference getLastTuple() throws HyracksDataException {
+        fta.reset(buffers.get(currentInUse));
+        int tupleIndex = fta.getTupleCount() - 1;
+        if (tupleIndex < 0) {
+            return null;
+        }
+        lastTuple.reset(fta, tupleIndex);
+        return lastTuple;
+    }
+
     private void allocate(int index) throws HyracksDataException {
         if (index >= buffers.size()) {
             buffers.add(ctx.allocateFrame());
diff --git a/pregelix/pregelix-dataflow/pom.xml b/pregelix/pregelix-dataflow/pom.xml
index 2828451..1df75ae 100644
--- a/pregelix/pregelix-dataflow/pom.xml
+++ b/pregelix/pregelix-dataflow/pom.xml
@@ -7,8 +7,7 @@
 	WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. ! See the 
 	License for the specific language governing permissions and ! limitations 
 	under the License. ! -->
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<artifactId>pregelix-dataflow</artifactId>
 	<packaging>jar</packaging>
@@ -17,7 +16,7 @@
 	<parent>
 		<groupId>edu.uci.ics.hyracks</groupId>
 		<artifactId>pregelix</artifactId>
-		<version>0.2.7-SNAPSHOT</version>
+		<version>0.2.10-SNAPSHOT</version>
 	</parent>
 
 
@@ -84,75 +83,75 @@
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>pregelix-api</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>pregelix-dataflow-std-base</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-api</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-dataflow-common</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-data-std</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-storage-am-common</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-storage-am-btree</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-storage-am-lsm-common</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-control-cc</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-control-nc</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-ipc</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
diff --git a/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/ClearStateOperatorDescriptor.java b/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/ClearStateOperatorDescriptor.java
new file mode 100644
index 0000000..d86557b
--- /dev/null
+++ b/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/ClearStateOperatorDescriptor.java
@@ -0,0 +1,82 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.dataflow;
+
+import edu.uci.ics.hyracks.api.comm.IFrameWriter;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
+import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
+import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.job.JobSpecification;
+import edu.uci.ics.hyracks.dataflow.std.base.AbstractSingleActivityOperatorDescriptor;
+import edu.uci.ics.pregelix.dataflow.context.RuntimeContext;
+
+/**
+ * Clear the state of the RuntimeContext in one slave
+ * 
+ * @author yingyib
+ */
+public class ClearStateOperatorDescriptor extends AbstractSingleActivityOperatorDescriptor {
+    private static final long serialVersionUID = 1L;
+    private String jobId;
+
+    public ClearStateOperatorDescriptor(JobSpecification spec, String jobId) {
+        super(spec, 0, 0);
+        this.jobId = jobId;
+    }
+
+    @Override
+    public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx,
+            IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) throws HyracksDataException {
+        return new IOperatorNodePushable() {
+
+            @Override
+            public void initialize() throws HyracksDataException {
+                RuntimeContext context = (RuntimeContext) ctx.getJobletContext().getApplicationContext()
+                        .getApplicationObject();
+                context.clearState(jobId);
+            }
+
+            @Override
+            public void deinitialize() throws HyracksDataException {
+
+            }
+
+            @Override
+            public int getInputArity() {
+                return 0;
+            }
+
+            @Override
+            public void setOutputFrameWriter(int index, IFrameWriter writer, RecordDescriptor recordDesc)
+                    throws HyracksDataException {
+
+            }
+
+            @Override
+            public IFrameWriter getInputFrameWriter(int index) {
+                return null;
+            }
+
+            @Override
+            public String getDisplayName() {
+                return "Clear State Operator";
+            }
+
+        };
+    }
+
+}
diff --git a/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/FinalAggregateOperatorDescriptor.java b/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/FinalAggregateOperatorDescriptor.java
index 3fed609..c0be9dd 100644
--- a/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/FinalAggregateOperatorDescriptor.java
+++ b/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/FinalAggregateOperatorDescriptor.java
@@ -17,9 +17,13 @@
 
 import java.io.DataInput;
 import java.io.DataInputStream;
+import java.io.IOException;
 import java.nio.ByteBuffer;
 
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.io.Writable;
 
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
@@ -32,6 +36,7 @@
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractSingleActivityOperatorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractUnaryInputSinkOperatorNodePushable;
 import edu.uci.ics.pregelix.api.graph.GlobalAggregator;
+import edu.uci.ics.pregelix.api.graph.Vertex;
 import edu.uci.ics.pregelix.api.util.BspUtils;
 import edu.uci.ics.pregelix.dataflow.base.IConfigurationFactory;
 import edu.uci.ics.pregelix.dataflow.std.base.IRecordDescriptorFactory;
@@ -93,10 +98,28 @@
 
             }
 
+            @SuppressWarnings("unchecked")
             @Override
             public void close() throws HyracksDataException {
-                Writable finalAggregateValue = aggregator.finishFinal();
-                IterationUtils.writeGlobalAggregateValue(conf, jobId, finalAggregateValue);
+                try {
+                    // iterate over hdfs spilled aggregates
+                    FileSystem dfs = FileSystem.get(conf);
+                    String spillingDir = BspUtils.getGlobalAggregateSpillingDirName(conf, Vertex.getSuperstep());
+                    FileStatus[] files = dfs.listStatus(new Path(spillingDir));
+                    if (files != null) {
+                        // goes into this branch only when there are spilled files
+                        for (int i = 0; i < files.length; i++) {
+                            FileStatus file = files[i];
+                            DataInput dis = dfs.open(file.getPath());
+                            partialAggregateValue.readFields(dis);
+                            aggregator.step(partialAggregateValue);
+                        }
+                    }
+                    Writable finalAggregateValue = aggregator.finishFinal();
+                    IterationUtils.writeGlobalAggregateValue(conf, jobId, finalAggregateValue);
+                } catch (IOException e) {
+                    throw new HyracksDataException(e);
+                }
             }
 
         };
diff --git a/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/HDFSFileWriteOperatorDescriptor.java b/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/HDFSFileWriteOperatorDescriptor.java
index b74a5de..a1177c8 100644
--- a/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/HDFSFileWriteOperatorDescriptor.java
+++ b/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/HDFSFileWriteOperatorDescriptor.java
@@ -19,42 +19,45 @@
 import java.io.IOException;
 import java.nio.ByteBuffer;
 
-import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileStatus;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.fs.PathFilter;
-import org.apache.hadoop.mapreduce.JobContext;
+import org.apache.hadoop.mapreduce.Job;
+import org.apache.hadoop.mapreduce.OutputFormat;
+import org.apache.hadoop.mapreduce.RecordWriter;
 import org.apache.hadoop.mapreduce.TaskAttemptContext;
 import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
+import org.apache.hadoop.util.ReflectionUtils;
 
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 import edu.uci.ics.hyracks.api.job.JobSpecification;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameDeserializer;
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractSingleActivityOperatorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractUnaryInputSinkOperatorNodePushable;
 import edu.uci.ics.hyracks.hdfs.ContextFactory;
-import edu.uci.ics.pregelix.api.graph.Vertex;
-import edu.uci.ics.pregelix.api.io.VertexOutputFormat;
-import edu.uci.ics.pregelix.api.io.VertexWriter;
-import edu.uci.ics.pregelix.api.util.BspUtils;
-import edu.uci.ics.pregelix.dataflow.base.IConfigurationFactory;
+import edu.uci.ics.hyracks.hdfs2.dataflow.ConfFactory;
 import edu.uci.ics.pregelix.dataflow.std.base.IRecordDescriptorFactory;
 
 public class HDFSFileWriteOperatorDescriptor extends AbstractSingleActivityOperatorDescriptor {
     private static final long serialVersionUID = 1L;
-    private final IConfigurationFactory confFactory;
+    private final ConfFactory confFactory;
     private final IRecordDescriptorFactory inputRdFactory;
 
-    public HDFSFileWriteOperatorDescriptor(JobSpecification spec, IConfigurationFactory confFactory,
-            IRecordDescriptorFactory inputRdFactory) {
+    public HDFSFileWriteOperatorDescriptor(JobSpecification spec, Job conf, IRecordDescriptorFactory inputRdFactory)
+            throws HyracksException {
         super(spec, 1, 0);
-        this.confFactory = confFactory;
-        this.inputRdFactory = inputRdFactory;
+        try {
+            this.confFactory = new ConfFactory(conf);
+            this.inputRdFactory = inputRdFactory;
+        } catch (Exception e) {
+            throw new HyracksException(e);
+        }
     }
 
     @SuppressWarnings("rawtypes")
@@ -65,12 +68,12 @@
         return new AbstractUnaryInputSinkOperatorNodePushable() {
             private RecordDescriptor rd0;
             private FrameDeserializer frameDeserializer;
-            private Configuration conf;
-            private VertexWriter vertexWriter;
+            private Job job;
+            private RecordWriter recordWriter;
             private TaskAttemptContext context;
+            private ContextFactory ctxFactory = new ContextFactory();
             private String TEMP_DIR = "_temporary";
             private ClassLoader ctxCL;
-            private ContextFactory ctxFactory = new ContextFactory();
 
             @Override
             public void open() throws HyracksDataException {
@@ -79,16 +82,16 @@
                 frameDeserializer = new FrameDeserializer(ctx.getFrameSize(), rd0);
                 ctxCL = Thread.currentThread().getContextClassLoader();
                 Thread.currentThread().setContextClassLoader(this.getClass().getClassLoader());
-                conf = confFactory.createConfiguration(ctx);
-
-                VertexOutputFormat outputFormat = BspUtils.createVertexOutputFormat(conf);
-                context = ctxFactory.createContext(conf, partition);
-                context.getConfiguration().setClassLoader(ctx.getJobletContext().getClassLoader());
+                job = confFactory.getConf();
                 try {
-                    vertexWriter = outputFormat.createVertexWriter(context);
+                    OutputFormat outputFormat = ReflectionUtils.newInstance(job.getOutputFormatClass(),
+                            job.getConfiguration());
+                    context = ctxFactory.createContext(job.getConfiguration(), partition);
+                    context.getConfiguration().setClassLoader(ctx.getJobletContext().getClassLoader());
+                    recordWriter = outputFormat.getRecordWriter(context);
                 } catch (InterruptedException e) {
                     throw new HyracksDataException(e);
-                } catch (IOException e) {
+                } catch (Exception e) {
                     throw new HyracksDataException(e);
                 }
             }
@@ -100,8 +103,9 @@
                 try {
                     while (!frameDeserializer.done()) {
                         Object[] tuple = frameDeserializer.deserializeRecord();
-                        Vertex value = (Vertex) tuple[1];
-                        vertexWriter.writeVertex(value);
+                        Object key = tuple[0];
+                        Object value = tuple[1];
+                        recordWriter.write(key, value);
                     }
                 } catch (InterruptedException e) {
                     throw new HyracksDataException(e);
@@ -118,7 +122,7 @@
             @Override
             public void close() throws HyracksDataException {
                 try {
-                    vertexWriter.close(context);
+                    recordWriter.close(context);
                     moveFilesToFinalPath();
                 } catch (InterruptedException e) {
                     throw new HyracksDataException(e);
@@ -129,9 +133,8 @@
 
             private void moveFilesToFinalPath() throws HyracksDataException {
                 try {
-                    JobContext job = ctxFactory.createJobContext(conf);
                     Path outputPath = FileOutputFormat.getOutputPath(job);
-                    FileSystem dfs = FileSystem.get(conf);
+                    FileSystem dfs = FileSystem.get(job.getConfiguration());
                     Path filePath = new Path(outputPath, "part-" + new Integer(partition).toString());
                     FileStatus[] results = findPartitionPaths(outputPath, dfs);
                     if (results.length >= 1) {
@@ -161,14 +164,15 @@
                 FileStatus[] tempPaths = dfs.listStatus(outputPath, new PathFilter() {
                     @Override
                     public boolean accept(Path dir) {
-                        return dir.getName().endsWith(TEMP_DIR);
+                        return dir.getName().endsWith(TEMP_DIR) && dir.getName().indexOf(".crc") < 0;
                     }
                 });
                 Path tempDir = tempPaths[0].getPath();
                 FileStatus[] results = dfs.listStatus(tempDir, new PathFilter() {
                     @Override
                     public boolean accept(Path dir) {
-                        return dir.getName().indexOf(context.getTaskAttemptID().toString()) >= 0;
+                        return dir.getName().indexOf(context.getTaskAttemptID().toString()) >= 0
+                                && dir.getName().indexOf(".crc") < 0;
                     }
                 });
                 return results;
diff --git a/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/KeyValueParserFactory.java b/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/KeyValueParserFactory.java
new file mode 100644
index 0000000..a4a53e1
--- /dev/null
+++ b/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/KeyValueParserFactory.java
@@ -0,0 +1,79 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.dataflow;
+
+import java.io.DataOutput;
+import java.nio.ByteBuffer;
+
+import org.apache.hadoop.io.Writable;
+
+import edu.uci.ics.hyracks.api.comm.IFrameWriter;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
+import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAppender;
+import edu.uci.ics.hyracks.dataflow.common.comm.util.FrameUtils;
+import edu.uci.ics.hyracks.hdfs.api.IKeyValueParser;
+import edu.uci.ics.hyracks.hdfs.api.IKeyValueParserFactory;
+
+/**
+ * @author yingyib
+ */
+public class KeyValueParserFactory<K extends Writable, V extends Writable> implements IKeyValueParserFactory<K, V> {
+    private static final long serialVersionUID = 1L;
+
+    @Override
+    public IKeyValueParser<K, V> createKeyValueParser(IHyracksTaskContext ctx) throws HyracksDataException {
+        final ArrayTupleBuilder tb = new ArrayTupleBuilder(2);
+        final DataOutput dos = tb.getDataOutput();
+        final ByteBuffer buffer = ctx.allocateFrame();
+        final FrameTupleAppender appender = new FrameTupleAppender(ctx.getFrameSize());
+        appender.reset(buffer, true);
+
+        return new IKeyValueParser<K, V>() {
+
+            @Override
+            public void open(IFrameWriter writer) throws HyracksDataException {
+
+            }
+
+            @Override
+            public void parse(K key, V value, IFrameWriter writer, String fileString) throws HyracksDataException {
+                try {
+                    tb.reset();
+                    key.write(dos);
+                    tb.addFieldEndOffset();
+                    value.write(dos);
+                    tb.addFieldEndOffset();
+                    if (!appender.append(tb.getFieldEndOffsets(), tb.getByteArray(), 0, tb.getSize())) {
+                        FrameUtils.flushFrame(buffer, writer);
+                        appender.reset(buffer, true);
+                        if (!appender.append(tb.getFieldEndOffsets(), tb.getByteArray(), 0, tb.getSize())) {
+                            throw new HyracksDataException("tuple cannot be appended into the frame");
+                        }
+                    }
+                } catch (Exception e) {
+                    throw new HyracksDataException(e);
+                }
+            }
+
+            @Override
+            public void close(IFrameWriter writer) throws HyracksDataException {
+                FrameUtils.flushFrame(buffer, writer);
+            }
+
+        };
+    }
+}
diff --git a/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/KeyValueWriterFactory.java b/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/KeyValueWriterFactory.java
new file mode 100644
index 0000000..fd407be
--- /dev/null
+++ b/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/KeyValueWriterFactory.java
@@ -0,0 +1,106 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.dataflow;
+
+import java.io.DataInput;
+import java.io.DataInputStream;
+import java.io.DataOutput;
+
+import org.apache.hadoop.io.Writable;
+import org.apache.hadoop.mapreduce.Job;
+import org.apache.hadoop.mapreduce.RecordWriter;
+import org.apache.hadoop.mapreduce.TaskAttemptContext;
+import org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat;
+
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
+import edu.uci.ics.hyracks.dataflow.common.util.ReflectionUtils;
+import edu.uci.ics.hyracks.hdfs.ContextFactory;
+import edu.uci.ics.hyracks.hdfs.api.ITupleWriter;
+import edu.uci.ics.hyracks.hdfs.api.ITupleWriterFactory;
+import edu.uci.ics.hyracks.hdfs2.dataflow.ConfFactory;
+import edu.uci.ics.pregelix.api.util.ResetableByteArrayInputStream;
+
+/**
+ * @author yingyib
+ */
+@SuppressWarnings("rawtypes")
+public class KeyValueWriterFactory implements ITupleWriterFactory {
+    private static final long serialVersionUID = 1L;
+    private ConfFactory confFactory;
+
+    public KeyValueWriterFactory(ConfFactory confFactory) {
+        this.confFactory = confFactory;
+    }
+
+    @Override
+    public ITupleWriter getTupleWriter(IHyracksTaskContext ctx, final int partition, final int nPartition)
+            throws HyracksDataException {
+        return new ITupleWriter() {
+            private SequenceFileOutputFormat sequenceOutputFormat = new SequenceFileOutputFormat();
+            private Writable key;
+            private Writable value;
+            private ResetableByteArrayInputStream bis = new ResetableByteArrayInputStream();
+            private DataInput dis = new DataInputStream(bis);
+            private RecordWriter recordWriter;
+            private ContextFactory ctxFactory = new ContextFactory();
+            private TaskAttemptContext context;
+
+            @Override
+            public void open(DataOutput output) throws HyracksDataException {
+                try {
+                    Job job = confFactory.getConf();
+                    context = ctxFactory.createContext(job.getConfiguration(), partition);
+                    recordWriter = sequenceOutputFormat.getRecordWriter(context);
+                    Class<?> keyClass = context.getOutputKeyClass();
+                    Class<?> valClass = context.getOutputValueClass();
+                    key = (Writable) ReflectionUtils.createInstance(keyClass);
+                    value = (Writable) ReflectionUtils.createInstance(valClass);
+                } catch (Exception e) {
+                    throw new HyracksDataException(e);
+                }
+            }
+
+            @SuppressWarnings("unchecked")
+            @Override
+            public void write(DataOutput output, ITupleReference tuple) throws HyracksDataException {
+                try {
+                    byte[] data = tuple.getFieldData(0);
+                    int fieldStart = tuple.getFieldStart(0);
+                    bis.setByteArray(data, fieldStart);
+                    key.readFields(dis);
+                    data = tuple.getFieldData(1);
+                    fieldStart = tuple.getFieldStart(1);
+                    bis.setByteArray(data, fieldStart);
+                    value.readFields(dis);
+                    recordWriter.write(key, value);
+                } catch (Exception e) {
+                    throw new HyracksDataException(e);
+                }
+            }
+
+            @Override
+            public void close(DataOutput output) throws HyracksDataException {
+                try {
+                    recordWriter.close(context);
+                } catch (Exception e) {
+                    throw new HyracksDataException(e);
+                }
+            }
+
+        };
+    }
+}
diff --git a/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/MaterializingReadOperatorDescriptor.java b/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/MaterializingReadOperatorDescriptor.java
index ca8f190..b44b643 100644
--- a/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/MaterializingReadOperatorDescriptor.java
+++ b/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/MaterializingReadOperatorDescriptor.java
@@ -30,9 +30,12 @@
 
 public class MaterializingReadOperatorDescriptor extends AbstractSingleActivityOperatorDescriptor {
     private static final long serialVersionUID = 1L;
+    private final boolean removeIterationState;
 
-    public MaterializingReadOperatorDescriptor(JobSpecification spec, RecordDescriptor recordDescriptor) {
+    public MaterializingReadOperatorDescriptor(JobSpecification spec, RecordDescriptor recordDescriptor,
+            boolean removeIterationState) {
         super(spec, 1, 1);
+        this.removeIterationState = removeIterationState;
         recordDescriptors[0] = recordDescriptor;
     }
 
@@ -73,7 +76,7 @@
 
             @Override
             public void fail() throws HyracksDataException {
-
+                writer.fail();
             }
 
             @Override
@@ -81,7 +84,9 @@
                 /**
                  * remove last iteration's state
                  */
-                IterationUtils.removeIterationState(ctx, partition);
+                if (removeIterationState) {
+                    IterationUtils.removeIterationState(ctx, partition);
+                }
                 writer.close();
                 complete = true;
             }
diff --git a/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/MaterializingWriteOperatorDescriptor.java b/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/MaterializingWriteOperatorDescriptor.java
index 48ed806..00dcbd1 100644
--- a/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/MaterializingWriteOperatorDescriptor.java
+++ b/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/MaterializingWriteOperatorDescriptor.java
@@ -68,6 +68,8 @@
 
                 @Override
                 public void open() throws HyracksDataException {
+                    /** remove last iteration's state */
+                    IterationUtils.removeIterationState(ctx, partition);
                     state = new MaterializerTaskState(ctx.getJobletContext().getJobId(), new TaskId(getActivityId(),
                             partition));
                     INCApplicationContext appContext = ctx.getJobletContext().getApplicationContext();
diff --git a/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/VertexFileWriteOperatorDescriptor.java b/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/VertexFileWriteOperatorDescriptor.java
new file mode 100644
index 0000000..f3ec40e
--- /dev/null
+++ b/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/VertexFileWriteOperatorDescriptor.java
@@ -0,0 +1,192 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.dataflow;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.fs.PathFilter;
+import org.apache.hadoop.mapreduce.JobContext;
+import org.apache.hadoop.mapreduce.TaskAttemptContext;
+import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
+
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
+import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
+import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.job.JobSpecification;
+import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameDeserializer;
+import edu.uci.ics.hyracks.dataflow.std.base.AbstractSingleActivityOperatorDescriptor;
+import edu.uci.ics.hyracks.dataflow.std.base.AbstractUnaryInputSinkOperatorNodePushable;
+import edu.uci.ics.hyracks.hdfs.ContextFactory;
+import edu.uci.ics.pregelix.api.graph.Vertex;
+import edu.uci.ics.pregelix.api.io.VertexOutputFormat;
+import edu.uci.ics.pregelix.api.io.VertexWriter;
+import edu.uci.ics.pregelix.api.util.BspUtils;
+import edu.uci.ics.pregelix.dataflow.base.IConfigurationFactory;
+import edu.uci.ics.pregelix.dataflow.std.base.IRecordDescriptorFactory;
+
+public class VertexFileWriteOperatorDescriptor extends AbstractSingleActivityOperatorDescriptor {
+    private static final long serialVersionUID = 1L;
+    private final IConfigurationFactory confFactory;
+    private final IRecordDescriptorFactory inputRdFactory;
+
+    public VertexFileWriteOperatorDescriptor(JobSpecification spec, IConfigurationFactory confFactory,
+            IRecordDescriptorFactory inputRdFactory) {
+        super(spec, 1, 0);
+        this.confFactory = confFactory;
+        this.inputRdFactory = inputRdFactory;
+    }
+
+    @SuppressWarnings("rawtypes")
+    @Override
+    public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx,
+            final IRecordDescriptorProvider recordDescProvider, final int partition, int nPartitions)
+            throws HyracksDataException {
+        return new AbstractUnaryInputSinkOperatorNodePushable() {
+            private RecordDescriptor rd0;
+            private FrameDeserializer frameDeserializer;
+            private Configuration conf;
+            private VertexWriter vertexWriter;
+            private TaskAttemptContext context;
+            private String TEMP_DIR = "_temporary";
+            private ClassLoader ctxCL;
+            private ContextFactory ctxFactory = new ContextFactory();
+
+            @Override
+            public void open() throws HyracksDataException {
+                rd0 = inputRdFactory == null ? recordDescProvider.getInputRecordDescriptor(getActivityId(), 0)
+                        : inputRdFactory.createRecordDescriptor(ctx);
+                frameDeserializer = new FrameDeserializer(ctx.getFrameSize(), rd0);
+                ctxCL = Thread.currentThread().getContextClassLoader();
+                Thread.currentThread().setContextClassLoader(this.getClass().getClassLoader());
+                conf = confFactory.createConfiguration(ctx);
+
+                VertexOutputFormat outputFormat = BspUtils.createVertexOutputFormat(conf);
+                context = ctxFactory.createContext(conf, partition);
+                context.getConfiguration().setClassLoader(ctx.getJobletContext().getClassLoader());
+                try {
+                    vertexWriter = outputFormat.createVertexWriter(context);
+                } catch (InterruptedException e) {
+                    throw new HyracksDataException(e);
+                } catch (IOException e) {
+                    throw new HyracksDataException(e);
+                }
+            }
+
+            @SuppressWarnings("unchecked")
+            @Override
+            public void nextFrame(ByteBuffer frame) throws HyracksDataException {
+                frameDeserializer.reset(frame);
+                try {
+                    while (!frameDeserializer.done()) {
+                        Object[] tuple = frameDeserializer.deserializeRecord();
+                        Vertex value = (Vertex) tuple[1];
+                        vertexWriter.writeVertex(value);
+                    }
+                } catch (InterruptedException e) {
+                    throw new HyracksDataException(e);
+                } catch (IOException e) {
+                    throw new HyracksDataException(e);
+                }
+            }
+
+            @Override
+            public void fail() throws HyracksDataException {
+                Thread.currentThread().setContextClassLoader(ctxCL);
+            }
+
+            @Override
+            public void close() throws HyracksDataException {
+                try {
+                    vertexWriter.close(context);
+                    moveFilesToFinalPath();
+                } catch (InterruptedException e) {
+                    throw new HyracksDataException(e);
+                } catch (IOException e) {
+                    throw new HyracksDataException(e);
+                }
+            }
+
+            private void moveFilesToFinalPath() throws HyracksDataException {
+                try {
+                    JobContext job = ctxFactory.createJobContext(conf);
+                    Path outputPath = FileOutputFormat.getOutputPath(job);
+                    FileSystem dfs = FileSystem.get(conf);
+                    Path filePath = new Path(outputPath, "part-" + new Integer(partition).toString());
+                    FileStatus[] results = findPartitionPaths(outputPath, dfs);
+                    if (results.length >= 1) {
+                        /**
+                         * for Hadoop-0.20.2
+                         */
+                        renameFile(dfs, filePath, results);
+                    } else {
+                        /**
+                         * for Hadoop-0.23.1
+                         */
+                        int jobId = job.getJobID().getId();
+                        outputPath = new Path(outputPath.toString() + File.separator + TEMP_DIR + File.separator
+                                + jobId);
+                        results = findPartitionPaths(outputPath, dfs);
+                        renameFile(dfs, filePath, results);
+                    }
+                } catch (IOException e) {
+                    throw new HyracksDataException(e);
+                } finally {
+                    Thread.currentThread().setContextClassLoader(ctxCL);
+                }
+            }
+
+            private FileStatus[] findPartitionPaths(Path outputPath, FileSystem dfs) throws FileNotFoundException,
+                    IOException {
+                FileStatus[] tempPaths = dfs.listStatus(outputPath, new PathFilter() {
+                    @Override
+                    public boolean accept(Path dir) {
+                        return dir.getName().endsWith(TEMP_DIR) && dir.getName().indexOf(".crc") < 0;
+                    }
+                });
+                Path tempDir = tempPaths[0].getPath();
+                FileStatus[] results = dfs.listStatus(tempDir, new PathFilter() {
+                    @Override
+                    public boolean accept(Path dir) {
+                        return dir.getName().indexOf(context.getTaskAttemptID().toString()) >= 0
+                                && dir.getName().indexOf(".crc") < 0;
+                    }
+                });
+                return results;
+            }
+
+            private void renameFile(FileSystem dfs, Path filePath, FileStatus[] results) throws IOException,
+                    HyracksDataException, FileNotFoundException {
+                Path srcDir = results[0].getPath();
+                if (!dfs.exists(srcDir))
+                    throw new HyracksDataException("file " + srcDir.toString() + " does not exist!");
+
+                FileStatus[] srcFiles = dfs.listStatus(srcDir);
+                Path srcFile = srcFiles[0].getPath();
+                dfs.delete(filePath, true);
+                dfs.rename(srcFile, filePath);
+            }
+
+        };
+    }
+}
diff --git a/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/context/RuntimeContext.java b/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/context/RuntimeContext.java
index 24a0a9e..f3f7513 100644
--- a/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/context/RuntimeContext.java
+++ b/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/context/RuntimeContext.java
@@ -54,13 +54,14 @@
     private final ILocalResourceRepository localResourceRepository;
     private final ResourceIdFactory resourceIdFactory;
     private final IBufferCache bufferCache;
-    private final IVirtualBufferCache vBufferCache;
+    private final List<IVirtualBufferCache> vbcs;
     private final IFileMapManager fileMapManager;
-    private final Map<StateKey, IStateObject> appStateMap = new ConcurrentHashMap<StateKey, IStateObject>();
-    private final Map<String, Long> giraphJobIdToSuperStep = new ConcurrentHashMap<String, Long>();
-    private final Map<String, Boolean> giraphJobIdToMove = new ConcurrentHashMap<String, Boolean>();
     private final IOManager ioManager;
     private final Map<Long, List<FileReference>> iterationToFiles = new ConcurrentHashMap<Long, List<FileReference>>();
+    private final Map<StateKey, IStateObject> appStateMap = new ConcurrentHashMap<StateKey, IStateObject>();
+    private final Map<String, Long> jobIdToSuperStep = new ConcurrentHashMap<String, Long>();
+    private final Map<String, Boolean> jobIdToMove = new ConcurrentHashMap<String, Boolean>();
+
     private final ThreadFactory threadFactory = new ThreadFactory() {
         public Thread newThread(Runnable r) {
             return new Thread(r);
@@ -79,9 +80,11 @@
         bufferCache = new BufferCache(appCtx.getRootContext().getIOManager(), allocator, prs,
                 new PreDelayPageCleanerPolicy(Long.MAX_VALUE), fileMapManager, pageSize, numPages, 1000000,
                 threadFactory);
-        int numPagesInMemComponents = numPages / 4;
-        vBufferCache = new MultitenantVirtualBufferCache(new VirtualBufferCache(new HeapBufferAllocator(), pageSize,
-                numPagesInMemComponents));
+        int numPagesInMemComponents = numPages / 8;
+        vbcs = new ArrayList<IVirtualBufferCache>();
+        IVirtualBufferCache vBufferCache = new MultitenantVirtualBufferCache(new VirtualBufferCache(
+                new HeapBufferAllocator(), pageSize, numPagesInMemComponents));
+        vbcs.add(vBufferCache);
         ioManager = (IOManager) appCtx.getRootContext().getIOManager();
         lcManager = new NoBudgetIndexLifecycleManager();
         localResourceRepository = new TransientLocalResourceRepository();
@@ -100,6 +103,18 @@
         System.gc();
     }
 
+    public void clearState(String jobId) throws HyracksDataException {
+        for (Entry<Long, List<FileReference>> entry : iterationToFiles.entrySet())
+            for (FileReference fileRef : entry.getValue())
+                fileRef.delete();
+
+        iterationToFiles.clear();
+        appStateMap.clear();
+        jobIdToMove.remove(jobId);
+        jobIdToSuperStep.remove(jobId);
+        System.gc();
+    }
+
     public ILocalResourceRepository getLocalResourceRepository() {
         return localResourceRepository;
     }
@@ -116,8 +131,8 @@
         return bufferCache;
     }
 
-    public IVirtualBufferCache getVirtualBufferCache() {
-        return vBufferCache;
+    public List<IVirtualBufferCache> getVirtualBufferCaches() {
+        return vbcs;
     }
 
     public IFileMapProvider getFileMapManager() {
@@ -132,32 +147,69 @@
         return (RuntimeContext) ctx.getJobletContext().getApplicationContext().getApplicationObject();
     }
 
-    public synchronized void setVertexProperties(String giraphJobId, long numVertices, long numEdges) {
-        Boolean toMove = giraphJobIdToMove.get(giraphJobId);
+    public synchronized void setVertexProperties(String jobId, long numVertices, long numEdges, long currentIteration) {
+        Boolean toMove = jobIdToMove.get(jobId);
         if (toMove == null || toMove == true) {
-            if (giraphJobIdToSuperStep.get(giraphJobId) == null) {
-                giraphJobIdToSuperStep.put(giraphJobId, 0L);
+            if (jobIdToSuperStep.get(jobId) == null) {
+                if (currentIteration <= 0) {
+                    jobIdToSuperStep.put(jobId, 0L);
+                } else {
+                    jobIdToSuperStep.put(jobId, currentIteration);
+                }
             }
 
-            long superStep = giraphJobIdToSuperStep.get(giraphJobId);
+            long superStep = jobIdToSuperStep.get(jobId);
             List<FileReference> files = iterationToFiles.remove(superStep - 1);
             if (files != null) {
                 for (FileReference fileRef : files)
                     fileRef.delete();
             }
 
-            Vertex.setSuperstep(++superStep);
+            if (currentIteration > 0) {
+                Vertex.setSuperstep(currentIteration);
+            } else {
+                Vertex.setSuperstep(++superStep);
+            }
             Vertex.setNumVertices(numVertices);
             Vertex.setNumEdges(numEdges);
-            giraphJobIdToSuperStep.put(giraphJobId, superStep);
-            giraphJobIdToMove.put(giraphJobId, false);
+            jobIdToSuperStep.put(jobId, superStep);
+            jobIdToMove.put(jobId, false);
             LOGGER.info("start iteration " + Vertex.getSuperstep());
         }
         System.gc();
     }
 
-    public synchronized void endSuperStep(String giraphJobId) {
-        giraphJobIdToMove.put(giraphJobId, true);
+    public synchronized void recoverVertexProperties(String jobId, long numVertices, long numEdges,
+            long currentIteration) {
+        if (jobIdToSuperStep.get(jobId) == null) {
+            if (currentIteration <= 0) {
+                jobIdToSuperStep.put(jobId, 0L);
+            } else {
+                jobIdToSuperStep.put(jobId, currentIteration);
+            }
+        }
+
+        long superStep = jobIdToSuperStep.get(jobId);
+        List<FileReference> files = iterationToFiles.remove(superStep - 1);
+        if (files != null) {
+            for (FileReference fileRef : files)
+                fileRef.delete();
+        }
+
+        if (currentIteration > 0) {
+            Vertex.setSuperstep(currentIteration);
+        } else {
+            Vertex.setSuperstep(++superStep);
+        }
+        Vertex.setNumVertices(numVertices);
+        Vertex.setNumEdges(numEdges);
+        jobIdToSuperStep.put(jobId, superStep);
+        jobIdToMove.put(jobId, true);
+        LOGGER.info("recovered iteration " + Vertex.getSuperstep());
+    }
+
+    public synchronized void endSuperStep(String pregelixJobId) {
+        jobIdToMove.put(pregelixJobId, true);
         LOGGER.info("end iteration " + Vertex.getSuperstep());
     }
 
diff --git a/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/util/IterationUtils.java b/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/util/IterationUtils.java
index 1d7c979..02097bf 100644
--- a/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/util/IterationUtils.java
+++ b/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/util/IterationUtils.java
@@ -31,6 +31,7 @@
 import edu.uci.ics.hyracks.api.job.JobId;
 import edu.uci.ics.pregelix.api.job.PregelixJob;
 import edu.uci.ics.pregelix.api.util.BspUtils;
+import edu.uci.ics.pregelix.api.util.JobStateUtils;
 import edu.uci.ics.pregelix.dataflow.context.RuntimeContext;
 import edu.uci.ics.pregelix.dataflow.context.StateKey;
 
@@ -51,6 +52,11 @@
         RuntimeContext context = (RuntimeContext) appContext.getApplicationObject();
         Map<StateKey, IStateObject> map = context.getAppStateStore();
         IStateObject state = map.get(new StateKey(lastId, partition));
+        while (state == null) {
+            /** in case the last job is a checkpointing job */
+            lastId = new JobId(lastId.getId() - 1);
+            state = map.get(new StateKey(lastId, partition));
+        }
         return state;
     }
 
@@ -69,11 +75,19 @@
         context.endSuperStep(giraphJobId);
     }
 
-    public static void setProperties(String giraphJobId, IHyracksTaskContext ctx, Configuration conf) {
+    public static void setProperties(String jobId, IHyracksTaskContext ctx, Configuration conf, long currentIteration) {
         INCApplicationContext appContext = ctx.getJobletContext().getApplicationContext();
         RuntimeContext context = (RuntimeContext) appContext.getApplicationObject();
-        context.setVertexProperties(giraphJobId, conf.getLong(PregelixJob.NUM_VERTICE, -1),
-                conf.getLong(PregelixJob.NUM_EDGES, -1));
+        context.setVertexProperties(jobId, conf.getLong(PregelixJob.NUM_VERTICE, -1),
+                conf.getLong(PregelixJob.NUM_EDGES, -1), currentIteration);
+    }
+
+    public static void recoverProperties(String jobId, IHyracksTaskContext ctx, Configuration conf,
+            long currentIteration) {
+        INCApplicationContext appContext = ctx.getJobletContext().getApplicationContext();
+        RuntimeContext context = (RuntimeContext) appContext.getApplicationObject();
+        context.recoverVertexProperties(jobId, conf.getLong(PregelixJob.NUM_VERTICE, -1),
+                conf.getLong(PregelixJob.NUM_EDGES, -1), currentIteration);
     }
 
     public static void writeTerminationState(Configuration conf, String jobId, boolean terminate)
@@ -91,22 +105,6 @@
         }
     }
 
-    public static void writeForceTerminationState(Configuration conf, String jobId) throws HyracksDataException {
-        try {
-            FileSystem dfs = FileSystem.get(conf);
-            String pathStr = IterationUtils.TMP_DIR + jobId + "fterm";
-            Path path = new Path(pathStr);
-            if (!dfs.exists(path)) {
-                FSDataOutputStream output = dfs.create(path, true);
-                output.writeBoolean(true);
-                output.flush();
-                output.close();
-            }
-        } catch (IOException e) {
-            throw new HyracksDataException(e);
-        }
-    }
-
     public static void writeGlobalAggregateValue(Configuration conf, String jobId, Writable agg)
             throws HyracksDataException {
         try {
@@ -136,19 +134,12 @@
         }
     }
 
+    public static void writeForceTerminationState(Configuration conf, String jobId) throws HyracksDataException {
+        JobStateUtils.writeForceTerminationState(conf, jobId);
+    }
+
     public static boolean readForceTerminationState(Configuration conf, String jobId) throws HyracksDataException {
-        try {
-            FileSystem dfs = FileSystem.get(conf);
-            String pathStr = IterationUtils.TMP_DIR + jobId + "fterm";
-            Path path = new Path(pathStr);
-            if (dfs.exists(path)) {
-                return true;
-            } else {
-                return false;
-            }
-        } catch (IOException e) {
-            throw new HyracksDataException(e);
-        }
+        return JobStateUtils.readForceTerminationState(conf, jobId);
     }
 
     public static Writable readGlobalAggregateValue(Configuration conf, String jobId) throws HyracksDataException {
diff --git a/pregelix/pregelix-dist/pom.xml b/pregelix/pregelix-dist/pom.xml
index a868ff2..cec6efe 100644
--- a/pregelix/pregelix-dist/pom.xml
+++ b/pregelix/pregelix-dist/pom.xml
@@ -1,24 +1,19 @@
 <?xml version="1.0"?>
-<!--
- ! Copyright 2009-2013 by The Regents of the University of California
- ! Licensed under the Apache License, Version 2.0 (the "License");
- ! you may not use this file except in compliance with the License.
- ! you may obtain a copy of the License from
- ! 
- !     http://www.apache.org/licenses/LICENSE-2.0
- ! 
- ! Unless required by applicable law or agreed to in writing, software
- ! distributed under the License is distributed on an "AS IS" BASIS,
- ! WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- ! See the License for the specific language governing permissions and
- ! limitations under the License.
- !-->
+<!-- ! Copyright 2009-2013 by The Regents of the University of California 
+	! Licensed under the Apache License, Version 2.0 (the "License"); ! you may 
+	not use this file except in compliance with the License. ! you may obtain 
+	a copy of the License from ! ! http://www.apache.org/licenses/LICENSE-2.0 
+	! ! Unless required by applicable law or agreed to in writing, software ! 
+	distributed under the License is distributed on an "AS IS" BASIS, ! WITHOUT 
+	WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. ! See the 
+	License for the specific language governing permissions and ! limitations 
+	under the License. ! -->
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>edu.uci.ics.hyracks</groupId>
 		<artifactId>pregelix</artifactId>
-		<version>0.2.7-SNAPSHOT</version>
+		<version>0.2.10-SNAPSHOT</version>
 	</parent>
 	<artifactId>pregelix-dist</artifactId>
 	<name>pregelix-dist</name>
@@ -38,35 +33,40 @@
 				</configuration>
 			</plugin>
 			<plugin>
-                                <artifactId>maven-assembly-plugin</artifactId>
-                                <version>2.2-beta-5</version>
-                                <executions>
-                                        <execution>
-                                                <configuration>
-                                                        <descriptors>
-                                                                <descriptor>src/main/assembly/binary-assembly.xml</descriptor>
-                                                        </descriptors>
-                                                </configuration>
-                                                <phase>package</phase>
-                                                <goals>
-                                                        <goal>attached</goal>
-                                                </goals>
-                                        </execution>
-                                </executions>
-                        </plugin>
+				<artifactId>maven-assembly-plugin</artifactId>
+				<version>2.2-beta-5</version>
+				<executions>
+					<execution>
+						<configuration>
+							<descriptors>
+								<descriptor>src/main/assembly/binary-assembly.xml</descriptor>
+							</descriptors>
+						</configuration>
+						<phase>package</phase>
+						<goals>
+							<goal>attached</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
 		</plugins>
 	</build>
 	<dependencies>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>pregelix-core</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>pregelix-example</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 		</dependency>
+		<dependency>
+                        <groupId>edu.uci.ics.hyracks</groupId>
+                        <artifactId>pregelix-benchmark</artifactId>
+                        <version>0.2.10-SNAPSHOT</version>
+                </dependency>
 	</dependencies>
 </project>
diff --git a/pregelix/pregelix-dist/src/main/assembly/binary-assembly.xml b/pregelix/pregelix-dist/src/main/assembly/binary-assembly.xml
index ab46338..a0fc2ab 100644
--- a/pregelix/pregelix-dist/src/main/assembly/binary-assembly.xml
+++ b/pregelix/pregelix-dist/src/main/assembly/binary-assembly.xml
@@ -1,17 +1,12 @@
-<!--
- ! Copyright 2009-2013 by The Regents of the University of California
- ! Licensed under the Apache License, Version 2.0 (the "License");
- ! you may not use this file except in compliance with the License.
- ! you may obtain a copy of the License from
- ! 
- !     http://www.apache.org/licenses/LICENSE-2.0
- ! 
- ! Unless required by applicable law or agreed to in writing, software
- ! distributed under the License is distributed on an "AS IS" BASIS,
- ! WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- ! See the License for the specific language governing permissions and
- ! limitations under the License.
- !-->
+<!-- ! Copyright 2009-2013 by The Regents of the University of California 
+	! Licensed under the Apache License, Version 2.0 (the "License"); ! you may 
+	not use this file except in compliance with the License. ! you may obtain 
+	a copy of the License from ! ! http://www.apache.org/licenses/LICENSE-2.0 
+	! ! Unless required by applicable law or agreed to in writing, software ! 
+	distributed under the License is distributed on an "AS IS" BASIS, ! WITHOUT 
+	WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. ! See the 
+	License for the specific language governing permissions and ! limitations 
+	under the License. ! -->
 <assembly>
 	<id>binary-assembly</id>
 	<formats>
@@ -31,25 +26,25 @@
 			<fileMode>0755</fileMode>
 		</fileSet>
 		<fileSet>
-                        <directory>../pregelix-core/target/appassembler/lib</directory>
-                        <outputDirectory>lib</outputDirectory>
-                         <includes>
-                                <include>*.jar</include>
-                        </includes>
-                        <fileMode>0755</fileMode>
-                </fileSet>
-		<fileSet>
-                        <directory>../pregelix-example/target</directory>
-                        <outputDirectory>examples</outputDirectory>
-                         <includes>
-        			<include>*with-dependencies.jar</include>
-      			</includes>
+			<directory>../pregelix-core/target/appassembler/lib</directory>
+			<outputDirectory>lib</outputDirectory>
+			<includes>
+				<include>*.jar</include>
+			</includes>
 			<fileMode>0755</fileMode>
-                </fileSet>
+		</fileSet>
 		<fileSet>
-                        <directory>../pregelix-example/data</directory>
-                        <outputDirectory>data</outputDirectory>
-                        <fileMode>0755</fileMode>
-                </fileSet>
+			<directory>../pregelix-example/target</directory>
+			<outputDirectory>examples</outputDirectory>
+			<includes>
+				<include>*with-dependencies.jar</include>
+			</includes>
+			<fileMode>0755</fileMode>
+		</fileSet>
+		<fileSet>
+			<directory>../pregelix-example/data</directory>
+			<outputDirectory>data</outputDirectory>
+			<fileMode>0755</fileMode>
+		</fileSet>
 	</fileSets>
 </assembly>
diff --git a/pregelix/pregelix-dist/src/main/resources/scripts/copylog.sh b/pregelix/pregelix-dist/src/main/resources/scripts/copylog.sh
new file mode 100644
index 0000000..7767b2d
--- /dev/null
+++ b/pregelix/pregelix-dist/src/main/resources/scripts/copylog.sh
@@ -0,0 +1,7 @@
+. conf/cluster.properties
+
+NODEID=`hostname | cut -d '.' -f 1`
+#echo $NODEID
+
+#echo "rsync ${NCLOGS_DIR}/${NODEID}.log ${1}:${2}"
+rsync ${NCLOGS_DIR}/${NODEID}.log ${1}:${2}
diff --git a/pregelix/pregelix-dist/src/main/resources/scripts/dumpAll.sh b/pregelix/pregelix-dist/src/main/resources/scripts/dumpAll.sh
new file mode 100644
index 0000000..e7d45e8
--- /dev/null
+++ b/pregelix/pregelix-dist/src/main/resources/scripts/dumpAll.sh
@@ -0,0 +1,12 @@
+. conf/cluster.properties
+PREGELIX_PATH=`pwd`
+LOG_PATH=$PREGELIX_PATH/logs/
+rm -rf $LOG_PATH
+mkdir $LOG_PATH
+ccname=`hostname`
+
+for i in `cat conf/slaves`
+do
+   ssh $i "cd ${PREGELIX_PATH}; bin/dumptrace.sh; bin/copylog.sh ${ccname} ${LOG_PATH}"
+done
+
diff --git a/pregelix/pregelix-dist/src/main/resources/scripts/dumptrace.sh b/pregelix/pregelix-dist/src/main/resources/scripts/dumptrace.sh
new file mode 100644
index 0000000..9fe55f0
--- /dev/null
+++ b/pregelix/pregelix-dist/src/main/resources/scripts/dumptrace.sh
@@ -0,0 +1,15 @@
+echo `hostname`
+#Kill process
+PID=`ps -ef|grep ${USER}|grep java|grep 'Dapp.name=pregelixnc'|awk '{print $2}'`
+
+if [ "$PID" == "" ]; then
+  PID=`ps -ef|grep ${USER}|grep java|grep 'hyracks'|awk '{print $2}'`
+fi
+
+if [ "$PID" == "" ]; then
+  USERID=`id | sed 's/^uid=//;s/(.*$//'`
+  PID=`ps -ef|grep ${USERID}|grep java|grep 'Dapp.name=pregelixnc'|awk '{print $2}'`
+fi
+
+echo $PID
+kill -QUIT $PID
diff --git a/pregelix/pregelix-dist/src/main/resources/scripts/startcc.sh b/pregelix/pregelix-dist/src/main/resources/scripts/startcc.sh
index 2a6cab2..d7a0ead 100644
--- a/pregelix/pregelix-dist/src/main/resources/scripts/startcc.sh
+++ b/pregelix/pregelix-dist/src/main/resources/scripts/startcc.sh
@@ -58,8 +58,8 @@
 
 if [ -f "conf/topology.xml"  ]; then
 #Launch hyracks cc script with topology
-${PREGELIX_HOME}/bin/pregelixcc -client-net-ip-address $CCHOST -cluster-net-ip-address $CCHOST -client-net-port $CC_CLIENTPORT -cluster-net-port $CC_CLUSTERPORT -max-heartbeat-lapse-periods 999999 -default-max-job-attempts 0 -job-history-size 0 -cluster-topology "conf/topology.xml" &> $CCLOGS_DIR/cc.log &
+${PREGELIX_HOME}/bin/pregelixcc -client-net-ip-address $CCHOST -cluster-net-ip-address $CCHOST -client-net-port $CC_CLIENTPORT -cluster-net-port $CC_CLUSTERPORT -heartbeat-period 5000 -max-heartbeat-lapse-periods 4 -default-max-job-attempts 0 -job-history-size 0 -cluster-topology "conf/topology.xml" &> $CCLOGS_DIR/cc.log &
 else
 #Launch hyracks cc script without toplogy
-${PREGELIX_HOME}/bin/pregelixcc -client-net-ip-address $CCHOST -cluster-net-ip-address $CCHOST -client-net-port $CC_CLIENTPORT -cluster-net-port $CC_CLUSTERPORT -max-heartbeat-lapse-periods 999999 -default-max-job-attempts 0 -job-history-size 0 &> $CCLOGS_DIR/cc.log &
+${PREGELIX_HOME}/bin/pregelixcc -client-net-ip-address $CCHOST -cluster-net-ip-address $CCHOST -client-net-port $CC_CLIENTPORT -cluster-net-port $CC_CLUSTERPORT -heartbeat-period 5000 -max-heartbeat-lapse-periods 4 -default-max-job-attempts 0 -job-history-size 0 &> $CCLOGS_DIR/cc.log &
 fi
diff --git a/pregelix/pregelix-example/pom.xml b/pregelix/pregelix-example/pom.xml
index c2538b1..9994c0e 100644
--- a/pregelix/pregelix-example/pom.xml
+++ b/pregelix/pregelix-example/pom.xml
@@ -21,7 +21,7 @@
 	<parent>
 		<groupId>edu.uci.ics.hyracks</groupId>
 		<artifactId>pregelix</artifactId>
-		<version>0.2.7-SNAPSHOT</version>
+		<version>0.2.10-SNAPSHOT</version>
 	</parent>
 
 	<build>
@@ -94,7 +94,7 @@
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-clean-plugin</artifactId>
-				<version>2.4.1</version>
+				<version>2.5</version>
 				<configuration>
 					<filesets>
 						<fileset>
@@ -107,6 +107,7 @@
 								<include>expect*</include>
 								<include>ClusterController*</include>
 								<include>edu.uci.*</include>
+								<include>dev*</include>
 							</includes>
 						</fileset>
 					</filesets>
@@ -119,7 +120,7 @@
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>pregelix-core</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
diff --git a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/ConnectedComponentsVertex.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/ConnectedComponentsVertex.java
index 07d2d57..a280c45 100644
--- a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/ConnectedComponentsVertex.java
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/ConnectedComponentsVertex.java
@@ -139,6 +139,7 @@
         job.setVertexOutputFormatClass(SimpleConnectedComponentsVertexOutputFormat.class);
         job.setMessageCombinerClass(ConnectedComponentsVertex.SimpleMinCombiner.class);
         job.setNoramlizedKeyComputerClass(VLongNormalizedKeyComputer.class);
+        job.setDynamicVertexValueSize(true);
         Client.run(args, job);
     }
 
diff --git a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/EarlyTerminationVertex.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/EarlyTerminationVertex.java
new file mode 100644
index 0000000..e369d29
--- /dev/null
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/EarlyTerminationVertex.java
@@ -0,0 +1,106 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.pregelix.example;
+
+import java.io.IOException;
+import java.util.Iterator;
+
+import org.apache.hadoop.io.Text;
+import org.apache.hadoop.mapreduce.RecordWriter;
+import org.apache.hadoop.mapreduce.TaskAttemptContext;
+
+import edu.uci.ics.pregelix.api.graph.Vertex;
+import edu.uci.ics.pregelix.api.io.VertexWriter;
+import edu.uci.ics.pregelix.api.io.text.TextVertexOutputFormat;
+import edu.uci.ics.pregelix.api.io.text.TextVertexOutputFormat.TextVertexWriter;
+import edu.uci.ics.pregelix.api.job.PregelixJob;
+import edu.uci.ics.pregelix.example.client.Client;
+import edu.uci.ics.pregelix.example.data.VLongNormalizedKeyComputer;
+import edu.uci.ics.pregelix.example.inputformat.TextPageRankInputFormat;
+import edu.uci.ics.pregelix.example.io.VLongWritable;
+
+/**
+ * Demonstrates the basic Pregel PageRank implementation.
+ */
+public class EarlyTerminationVertex extends Vertex<VLongWritable, VLongWritable, VLongWritable, VLongWritable> {
+    private VLongWritable tempValue = new VLongWritable();
+
+    @Override
+    public void compute(Iterator<VLongWritable> msgIterator) {
+        if (getSuperstep() == 1) {
+            if (getVertexId().get() % 4 == 2) {
+                terminatePartition();
+            } else {
+                tempValue.set(1);
+                setVertexValue(tempValue);
+            }
+        }
+        if (getSuperstep() == 2) {
+            if (getVertexId().get() % 4 == 3) {
+                terminatePartition();
+            } else {
+                tempValue.set(2);
+                setVertexValue(tempValue);
+                voteToHalt();
+            }
+        }
+    }
+
+    @Override
+    public String toString() {
+        return getVertexId() + " " + getVertexValue();
+    }
+
+    /**
+     * Simple VertexWriter that support
+     */
+    public static class SimpleEarlyTerminattionVertexWriter extends
+            TextVertexWriter<VLongWritable, VLongWritable, VLongWritable> {
+        public SimpleEarlyTerminattionVertexWriter(RecordWriter<Text, Text> lineRecordWriter) {
+            super(lineRecordWriter);
+        }
+
+        @Override
+        public void writeVertex(Vertex<VLongWritable, VLongWritable, VLongWritable, ?> vertex) throws IOException,
+                InterruptedException {
+            getRecordWriter().write(new Text(vertex.getVertexId().toString()),
+                    new Text(vertex.getVertexValue().toString()));
+        }
+    }
+
+    public static class SimpleEarlyTerminattionVertexOutputFormat extends
+            TextVertexOutputFormat<VLongWritable, VLongWritable, VLongWritable> {
+
+        @Override
+        public VertexWriter<VLongWritable, VLongWritable, VLongWritable> createVertexWriter(TaskAttemptContext context)
+                throws IOException, InterruptedException {
+            RecordWriter<Text, Text> recordWriter = textOutputFormat.getRecordWriter(context);
+            return new SimpleEarlyTerminattionVertexWriter(recordWriter);
+        }
+
+    }
+
+    public static void main(String[] args) throws Exception {
+        PregelixJob job = new PregelixJob(EarlyTerminationVertex.class.getSimpleName());
+        job.setVertexClass(EarlyTerminationVertex.class);
+        job.setVertexInputFormatClass(TextPageRankInputFormat.class);
+        job.setVertexOutputFormatClass(SimpleEarlyTerminattionVertexOutputFormat.class);
+        job.setNoramlizedKeyComputerClass(VLongNormalizedKeyComputer.class);
+        job.setDynamicVertexValueSize(true);
+        Client.run(args, job);
+    }
+
+}
diff --git a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/GraphMutationVertex.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/GraphMutationVertex.java
index 7cf8408..7fae776 100644
--- a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/GraphMutationVertex.java
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/GraphMutationVertex.java
@@ -18,7 +18,6 @@
 import java.io.IOException;
 import java.util.Iterator;
 
-import org.apache.hadoop.io.DoubleWritable;
 import org.apache.hadoop.io.FloatWritable;
 import org.apache.hadoop.io.Text;
 import org.apache.hadoop.mapreduce.RecordWriter;
@@ -32,6 +31,7 @@
 import edu.uci.ics.pregelix.example.client.Client;
 import edu.uci.ics.pregelix.example.data.VLongNormalizedKeyComputer;
 import edu.uci.ics.pregelix.example.inputformat.TextPageRankInputFormat;
+import edu.uci.ics.pregelix.example.io.DoubleWritable;
 import edu.uci.ics.pregelix.example.io.VLongWritable;
 
 /**
diff --git a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/MessageOverflowFixedsizeVertex.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/MessageOverflowFixedsizeVertex.java
new file mode 100644
index 0000000..6c3c752
--- /dev/null
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/MessageOverflowFixedsizeVertex.java
@@ -0,0 +1,113 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.pregelix.example;
+
+import java.io.IOException;
+import java.util.Iterator;
+import java.util.Random;
+
+import org.apache.hadoop.io.Text;
+import org.apache.hadoop.mapreduce.RecordWriter;
+import org.apache.hadoop.mapreduce.TaskAttemptContext;
+
+import edu.uci.ics.pregelix.api.graph.Vertex;
+import edu.uci.ics.pregelix.api.io.VertexWriter;
+import edu.uci.ics.pregelix.api.io.text.TextVertexOutputFormat;
+import edu.uci.ics.pregelix.api.io.text.TextVertexOutputFormat.TextVertexWriter;
+import edu.uci.ics.pregelix.api.job.PregelixJob;
+import edu.uci.ics.pregelix.example.client.Client;
+import edu.uci.ics.pregelix.example.data.VLongNormalizedKeyComputer;
+import edu.uci.ics.pregelix.example.inputformat.TextPageRankInputFormat;
+import edu.uci.ics.pregelix.example.io.LongWritable;
+import edu.uci.ics.pregelix.example.io.VLongWritable;
+
+/**
+ * Demonstrates the basic Pregel PageRank implementation.
+ */
+public class MessageOverflowFixedsizeVertex extends Vertex<VLongWritable, LongWritable, VLongWritable, LongWritable> {
+
+    private LongWritable outputMsg = new LongWritable(1);
+    private Random rand = new Random(System.currentTimeMillis());
+    private LongWritable tmpVertexValue = new LongWritable(0);
+    private int numOfMsgClones = 10000;
+
+    @Override
+    public void compute(Iterator<LongWritable> msgIterator) {
+        if (getSuperstep() == 1) {
+            for (int i = 0; i < numOfMsgClones; i++) {
+                outputMsg.set(Math.abs(rand.nextLong()));
+                sendMsgToAllEdges(outputMsg);
+            }
+            tmpVertexValue.set(0);
+            setVertexValue(tmpVertexValue);
+        }
+        if (getSuperstep() == 2) {
+            long numOfMsg = getVertexValue().get();
+            while (msgIterator.hasNext()) {
+                msgIterator.next();
+                numOfMsg++;
+            }
+            tmpVertexValue.set(numOfMsg);
+            setVertexValue(tmpVertexValue);
+            voteToHalt();
+        }
+    }
+
+    @Override
+    public String toString() {
+        return getVertexId() + " " + getVertexValue();
+    }
+
+    /**
+     * Simple VertexWriter that support
+     */
+    public static class SimpleMessageOverflowVertexWriter extends
+            TextVertexWriter<VLongWritable, LongWritable, VLongWritable> {
+        public SimpleMessageOverflowVertexWriter(RecordWriter<Text, Text> lineRecordWriter) {
+            super(lineRecordWriter);
+        }
+
+        @Override
+        public void writeVertex(Vertex<VLongWritable, LongWritable, VLongWritable, ?> vertex) throws IOException,
+                InterruptedException {
+            getRecordWriter().write(new Text(vertex.getVertexId().toString()),
+                    new Text(vertex.getVertexValue().toString()));
+        }
+    }
+
+    public static class SimpleMessageOverflowVertexOutputFormat extends
+            TextVertexOutputFormat<VLongWritable, LongWritable, VLongWritable> {
+
+        @Override
+        public VertexWriter<VLongWritable, LongWritable, VLongWritable> createVertexWriter(TaskAttemptContext context)
+                throws IOException, InterruptedException {
+            RecordWriter<Text, Text> recordWriter = textOutputFormat.getRecordWriter(context);
+            return new SimpleMessageOverflowVertexWriter(recordWriter);
+        }
+
+    }
+
+    public static void main(String[] args) throws Exception {
+        PregelixJob job = new PregelixJob(MessageOverflowFixedsizeVertex.class.getSimpleName());
+        job.setVertexClass(MessageOverflowFixedsizeVertex.class);
+        job.setVertexInputFormatClass(TextPageRankInputFormat.class);
+        job.setVertexOutputFormatClass(SimpleMessageOverflowVertexOutputFormat.class);
+        job.setNoramlizedKeyComputerClass(VLongNormalizedKeyComputer.class);
+        job.setDynamicVertexValueSize(true);
+        Client.run(args, job);
+    }
+
+}
diff --git a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/MessageOverflowVertex.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/MessageOverflowVertex.java
new file mode 100644
index 0000000..d0221bf
--- /dev/null
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/MessageOverflowVertex.java
@@ -0,0 +1,125 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.pregelix.example;
+
+import java.io.IOException;
+import java.util.Iterator;
+import java.util.Random;
+
+import org.apache.hadoop.io.Text;
+import org.apache.hadoop.mapreduce.RecordWriter;
+import org.apache.hadoop.mapreduce.TaskAttemptContext;
+
+import edu.uci.ics.pregelix.api.graph.Vertex;
+import edu.uci.ics.pregelix.api.io.VertexWriter;
+import edu.uci.ics.pregelix.api.io.text.TextVertexOutputFormat;
+import edu.uci.ics.pregelix.api.io.text.TextVertexOutputFormat.TextVertexWriter;
+import edu.uci.ics.pregelix.api.job.PregelixJob;
+import edu.uci.ics.pregelix.example.client.Client;
+import edu.uci.ics.pregelix.example.data.VLongNormalizedKeyComputer;
+import edu.uci.ics.pregelix.example.inputformat.TextPageRankInputFormat;
+import edu.uci.ics.pregelix.example.io.VLongWritable;
+
+/**
+ * Demonstrates the basic Pregel PageRank implementation.
+ */
+public class MessageOverflowVertex extends Vertex<VLongWritable, VLongWritable, VLongWritable, VLongWritable> {
+
+    private VLongWritable outputMsg = new VLongWritable(1);
+    private Random rand = new Random(System.currentTimeMillis());
+    private VLongWritable tmpVertexValue = new VLongWritable(0);
+    private int numOfMsgClones = 10000;
+    private int numIncomingMsgs = 0;
+
+    @Override
+    public void open() {
+        if (getSuperstep() == 2) {
+            numIncomingMsgs = 0;
+        }
+    }
+
+    @Override
+    public void compute(Iterator<VLongWritable> msgIterator) {
+        if (getSuperstep() == 1) {
+            for (int i = 0; i < numOfMsgClones; i++) {
+                outputMsg.set(Math.abs(rand.nextLong()));
+                sendMsgToAllEdges(outputMsg);
+            }
+            tmpVertexValue.set(0);
+            setVertexValue(tmpVertexValue);
+        }
+        if (getSuperstep() == 2) {
+            while (msgIterator.hasNext()) {
+                msgIterator.next();
+                numIncomingMsgs++;
+            }
+        }
+    }
+
+    @Override
+    public void close() {
+        if (getSuperstep() == 2) {
+            tmpVertexValue.set(numIncomingMsgs);
+            setVertexValue(tmpVertexValue);
+            voteToHalt();
+        }
+    }
+
+    @Override
+    public String toString() {
+        return getVertexId() + " " + getVertexValue();
+    }
+
+    /**
+     * Simple VertexWriter that support
+     */
+    public static class SimpleMessageOverflowVertexWriter extends
+            TextVertexWriter<VLongWritable, VLongWritable, VLongWritable> {
+        public SimpleMessageOverflowVertexWriter(RecordWriter<Text, Text> lineRecordWriter) {
+            super(lineRecordWriter);
+        }
+
+        @Override
+        public void writeVertex(Vertex<VLongWritable, VLongWritable, VLongWritable, ?> vertex) throws IOException,
+                InterruptedException {
+            getRecordWriter().write(new Text(vertex.getVertexId().toString()),
+                    new Text(vertex.getVertexValue().toString()));
+        }
+    }
+
+    public static class SimpleMessageOverflowVertexOutputFormat extends
+            TextVertexOutputFormat<VLongWritable, VLongWritable, VLongWritable> {
+
+        @Override
+        public VertexWriter<VLongWritable, VLongWritable, VLongWritable> createVertexWriter(TaskAttemptContext context)
+                throws IOException, InterruptedException {
+            RecordWriter<Text, Text> recordWriter = textOutputFormat.getRecordWriter(context);
+            return new SimpleMessageOverflowVertexWriter(recordWriter);
+        }
+
+    }
+
+    public static void main(String[] args) throws Exception {
+        PregelixJob job = new PregelixJob(MessageOverflowVertex.class.getSimpleName());
+        job.setVertexClass(MessageOverflowVertex.class);
+        job.setVertexInputFormatClass(TextPageRankInputFormat.class);
+        job.setVertexOutputFormatClass(SimpleMessageOverflowVertexOutputFormat.class);
+        job.setNoramlizedKeyComputerClass(VLongNormalizedKeyComputer.class);
+        job.setDynamicVertexValueSize(true);
+        Client.run(args, job);
+    }
+
+}
diff --git a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/PageRankVertex.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/PageRankVertex.java
index 8664667..a866c1c 100644
--- a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/PageRankVertex.java
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/PageRankVertex.java
@@ -21,7 +21,6 @@
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
-import org.apache.hadoop.io.DoubleWritable;
 import org.apache.hadoop.io.FloatWritable;
 import org.apache.hadoop.io.Text;
 import org.apache.hadoop.mapreduce.InputSplit;
@@ -45,6 +44,7 @@
 import edu.uci.ics.pregelix.example.client.Client;
 import edu.uci.ics.pregelix.example.data.VLongNormalizedKeyComputer;
 import edu.uci.ics.pregelix.example.inputformat.TextPageRankInputFormat;
+import edu.uci.ics.pregelix.example.io.DoubleWritable;
 import edu.uci.ics.pregelix.example.io.VLongWritable;
 
 /**
diff --git a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/ReachabilityVertex.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/ReachabilityVertex.java
index 6a42636..1bb33b8 100644
--- a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/ReachabilityVertex.java
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/ReachabilityVertex.java
@@ -22,7 +22,6 @@
 import org.apache.hadoop.fs.FSDataOutputStream;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
-import org.apache.hadoop.io.ByteWritable;
 import org.apache.hadoop.io.FloatWritable;
 import org.apache.hadoop.io.Text;
 import org.apache.hadoop.mapreduce.RecordWriter;
@@ -42,6 +41,7 @@
 import edu.uci.ics.pregelix.example.client.Client;
 import edu.uci.ics.pregelix.example.data.VLongNormalizedKeyComputer;
 import edu.uci.ics.pregelix.example.inputformat.TextReachibilityVertexInputFormat;
+import edu.uci.ics.pregelix.example.io.ByteWritable;
 import edu.uci.ics.pregelix.example.io.VLongWritable;
 
 /**
@@ -116,7 +116,7 @@
     }
 
     @Override
-    public void compute(Iterator<ByteWritable> msgIterator) {
+    public void compute(Iterator<ByteWritable> msgIterator) throws Exception {
         if (sourceId < 0) {
             sourceId = getContext().getConfiguration().getLong(SOURCE_ID, SOURCE_ID_DEFAULT);
         }
@@ -171,13 +171,20 @@
         return getVertexId() + " " + getVertexValue();
     }
 
-    private void signalTerminate() {
-        Configuration conf = getContext().getConfiguration();
-        try {
-            IterationUtils.writeForceTerminationState(conf, BspUtils.getJobId(conf));
-            writeReachibilityResult(conf, true);
-        } catch (Exception e) {
-            throw new IllegalStateException(e);
+    private void signalTerminate() throws Exception {
+        writeReachibilityResult(getContext().getConfiguration(), true);
+        terminateJob();
+    }
+
+    private void writeReachibilityResult(Configuration conf, boolean terminate) throws IOException {
+        FileSystem dfs = FileSystem.get(conf);
+        String pathStr = IterationUtils.TMP_DIR + BspUtils.getJobId(conf) + "reachibility";
+        Path path = new Path(pathStr);
+        if (!dfs.exists(path)) {
+            FSDataOutputStream output = dfs.create(path, true);
+            output.writeBoolean(terminate);
+            output.flush();
+            output.close();
         }
     }
 
@@ -187,22 +194,6 @@
         }
     }
 
-    private void writeReachibilityResult(Configuration conf, boolean terminate) {
-        try {
-            FileSystem dfs = FileSystem.get(conf);
-            String pathStr = IterationUtils.TMP_DIR + BspUtils.getJobId(conf) + "reachibility";
-            Path path = new Path(pathStr);
-            if (!dfs.exists(path)) {
-                FSDataOutputStream output = dfs.create(path, true);
-                output.writeBoolean(terminate);
-                output.flush();
-                output.close();
-            }
-        } catch (IOException e) {
-            throw new IllegalStateException(e);
-        }
-    }
-
     private static boolean readReachibilityResult(Configuration conf) {
         try {
             FileSystem dfs = FileSystem.get(conf);
diff --git a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/ShortestPathsVertex.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/ShortestPathsVertex.java
index 41c26b1..648f168 100644
--- a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/ShortestPathsVertex.java
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/ShortestPathsVertex.java
@@ -19,7 +19,6 @@
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
-import org.apache.hadoop.io.DoubleWritable;
 import org.apache.hadoop.io.FloatWritable;
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
@@ -32,6 +31,7 @@
 import edu.uci.ics.pregelix.example.client.Client;
 import edu.uci.ics.pregelix.example.data.VLongNormalizedKeyComputer;
 import edu.uci.ics.pregelix.example.inputformat.TextShortestPathsInputFormat;
+import edu.uci.ics.pregelix.example.io.DoubleWritable;
 import edu.uci.ics.pregelix.example.io.VLongWritable;
 
 /**
@@ -127,7 +127,7 @@
         }
         voteToHalt();
     }
-    
+
     @Override
     public String toString() {
         return getVertexId() + " " + getVertexValue();
diff --git a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/client/Client.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/client/Client.java
index 6cb1f4a..393c8c9 100644
--- a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/client/Client.java
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/client/Client.java
@@ -16,6 +16,7 @@
 package edu.uci.ics.pregelix.example.client;
 
 import java.io.IOException;
+import java.util.List;
 
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
@@ -44,7 +45,7 @@
         public String ipAddress;
 
         @Option(name = "-port", usage = "port of cluster controller", required = false)
-        public int port;
+        public int port = 3099;
 
         @Option(name = "-plan", usage = "query plan choice", required = false)
         public Plan planChoice = Plan.OUTER_JOIN;
@@ -66,6 +67,9 @@
 
         @Option(name = "-runtime-profiling", usage = "whether to do runtime profifling", required = false)
         public String profiling = "false";
+
+        @Option(name = "-ckp-interval", usage = "checkpointing interval -- for fault-tolerance", required = false)
+        public int ckpInterval = -1;
     }
 
     public static void run(String[] args, PregelixJob job) throws Exception {
@@ -74,6 +78,13 @@
         driver.runJob(job, options.planChoice, options.ipAddress, options.port, Boolean.parseBoolean(options.profiling));
     }
 
+    public static void run(String[] args, List<PregelixJob> jobs) throws Exception {
+        Options options = prepareJobs(args, jobs);
+        Driver driver = new Driver(Client.class);
+        driver.runJobs(jobs, options.planChoice, options.ipAddress, options.port,
+                Boolean.parseBoolean(options.profiling));
+    }
+
     private static Options prepareJob(String[] args, PregelixJob job) throws CmdLineException, IOException {
         Options options = new Options();
         CmdLineParser parser = new CmdLineParser(options);
@@ -82,8 +93,34 @@
         String[] inputs = options.inputPaths.split(";");
         FileInputFormat.setInputPaths(job, inputs[0]);
         for (int i = 1; i < inputs.length; i++)
-            FileInputFormat.addInputPaths(job, inputs[0]);
+            FileInputFormat.addInputPaths(job, inputs[i]);
         FileOutputFormat.setOutputPath(job, new Path(options.outputPath));
+        setJobSpecificSettings(job, options);
+        return options;
+    }
+
+    private static Options prepareJobs(String[] args, List<PregelixJob> jobs) throws CmdLineException, IOException {
+        Options options = new Options();
+        CmdLineParser parser = new CmdLineParser(options);
+        parser.parseArgument(args);
+
+        for (int j = 0; j < jobs.size(); j++) {
+            PregelixJob job = jobs.get(j);
+            String[] inputs = options.inputPaths.split(";");
+            if (j == 0) {
+                FileInputFormat.setInputPaths(job, inputs[0]);
+                for (int i = 1; i < inputs.length; i++)
+                    FileInputFormat.addInputPaths(job, inputs[i]);
+            }
+            if (j == jobs.size() - 1) {
+                FileOutputFormat.setOutputPath(job, new Path(options.outputPath));
+            }
+            setJobSpecificSettings(job, options);
+        }
+        return options;
+    }
+
+    private static void setJobSpecificSettings(PregelixJob job, Options options) {
         job.getConfiguration().setLong(PregelixJob.NUM_VERTICE, options.numVertices);
         job.getConfiguration().setLong(PregelixJob.NUM_EDGES, options.numEdges);
         job.getConfiguration().setLong(ShortestPathsVertex.SOURCE_ID, options.sourceId);
@@ -91,7 +128,7 @@
         job.getConfiguration().setLong(ReachabilityVertex.DEST_ID, options.destId);
         if (options.numIteration > 0)
             job.getConfiguration().setLong(PageRankVertex.ITERATIONS, options.numIteration);
-        return options;
+        job.setCheckpointingInterval(options.ckpInterval);
     }
 
 }
diff --git a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/data/VLongNormalizedKeyComputer.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/data/VLongNormalizedKeyComputer.java
index 7d824ea..44d23a4 100644
--- a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/data/VLongNormalizedKeyComputer.java
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/data/VLongNormalizedKeyComputer.java
@@ -15,7 +15,7 @@
 package edu.uci.ics.pregelix.example.data;
 
 import edu.uci.ics.pregelix.api.graph.NormalizedKeyComputer;
-import edu.uci.ics.pregelix.api.util.SerDeUtils;
+import edu.uci.ics.pregelix.example.utils.SerDeUtils;
 
 /**
  * @author yingyib
@@ -28,32 +28,36 @@
 
     @Override
     public int getNormalizedKey(byte[] bytes, int start, int length) {
-        long value = SerDeUtils.readVLong(bytes, start, length);
-        int highValue = (int) (value >> 32);
-        if (highValue > 0) {
-            /**
-             * larger than Integer.MAX
-             */
-            int highNmk = getKey(highValue);
-            highNmk >>= 2;
-            highNmk |= POSTIVE_LONG_MASK;
-            return highNmk;
-        } else if (highValue == 0) {
-            /**
-             * smaller than Integer.MAX but >=0
-             */
-            int lowNmk = (int) value;
-            lowNmk >>= 2;
-            lowNmk |= NON_NEGATIVE_INT_MASK;
-            return lowNmk;
-        } else {
-            /**
-             * less than 0; TODO: have not optimized for that
-             */
-            int highNmk = getKey(highValue);
-            highNmk >>= 2;
-            highNmk |= NEGATIVE_LONG_MASK;
-            return highNmk;
+        try {
+            long value = SerDeUtils.readVLong(bytes, start, length);
+            int highValue = (int) (value >> 32);
+            if (highValue > 0) {
+                /**
+                 * larger than Integer.MAX
+                 */
+                int highNmk = getKey(highValue);
+                highNmk >>= 2;
+                highNmk |= POSTIVE_LONG_MASK;
+                return highNmk;
+            } else if (highValue == 0) {
+                /**
+                 * smaller than Integer.MAX but >=0
+                 */
+                int lowNmk = (int) value;
+                lowNmk >>= 2;
+                lowNmk |= NON_NEGATIVE_INT_MASK;
+                return lowNmk;
+            } else {
+                /**
+                 * less than 0; TODO: have not optimized for that
+                 */
+                int highNmk = getKey(highValue);
+                highNmk >>= 2;
+                highNmk |= NEGATIVE_LONG_MASK;
+                return highNmk;
+            }
+        } catch (Exception e) {
+            throw new IllegalStateException(e);
         }
     }
 
diff --git a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/inputformat/TextPageRankInputFormat.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/inputformat/TextPageRankInputFormat.java
index f46d9c3..67681d3 100644
--- a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/inputformat/TextPageRankInputFormat.java
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/inputformat/TextPageRankInputFormat.java
@@ -18,7 +18,6 @@
 import java.util.ArrayList;
 import java.util.List;
 
-import org.apache.hadoop.io.DoubleWritable;
 import org.apache.hadoop.io.FloatWritable;
 import org.apache.hadoop.io.LongWritable;
 import org.apache.hadoop.io.Text;
@@ -31,6 +30,7 @@
 import edu.uci.ics.pregelix.api.io.text.TextVertexInputFormat;
 import edu.uci.ics.pregelix.api.io.text.TextVertexInputFormat.TextVertexReader;
 import edu.uci.ics.pregelix.api.util.BspUtils;
+import edu.uci.ics.pregelix.example.io.DoubleWritable;
 import edu.uci.ics.pregelix.example.io.VLongWritable;
 
 public class TextPageRankInputFormat extends
diff --git a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/inputformat/TextShortestPathsInputFormat.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/inputformat/TextShortestPathsInputFormat.java
index 013a063..3ea4a9f 100644
--- a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/inputformat/TextShortestPathsInputFormat.java
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/inputformat/TextShortestPathsInputFormat.java
@@ -18,7 +18,6 @@
 import java.util.ArrayList;
 import java.util.List;
 
-import org.apache.hadoop.io.DoubleWritable;
 import org.apache.hadoop.io.FloatWritable;
 import org.apache.hadoop.io.LongWritable;
 import org.apache.hadoop.io.Text;
@@ -31,6 +30,7 @@
 import edu.uci.ics.pregelix.api.io.text.TextVertexInputFormat;
 import edu.uci.ics.pregelix.api.io.text.TextVertexInputFormat.TextVertexReader;
 import edu.uci.ics.pregelix.api.util.BspUtils;
+import edu.uci.ics.pregelix.example.io.DoubleWritable;
 import edu.uci.ics.pregelix.example.io.VLongWritable;
 
 public class TextShortestPathsInputFormat extends
diff --git a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/BooleanWritable.java
similarity index 61%
copy from hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
copy to pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/BooleanWritable.java
index cde5022..c943288 100644
--- a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/BooleanWritable.java
@@ -12,17 +12,25 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+package edu.uci.ics.pregelix.example.io;
 
-package edu.uci.ics.hyracks.storage.am.btree.exceptions;
+import edu.uci.ics.pregelix.api.io.WritableSizable;
 
-public class BTreeDuplicateKeyException extends BTreeException {
-    private static final long serialVersionUID = 1L;
+/**
+ * Writable for Boolean values.
+ */
+public class BooleanWritable extends org.apache.hadoop.io.BooleanWritable implements WritableSizable {
 
-    public BTreeDuplicateKeyException(Exception e) {
-        super(e);
+    public BooleanWritable(boolean value) {
+        super(value);
     }
 
-    public BTreeDuplicateKeyException(String message) {
-        super(message);
+    public BooleanWritable() {
+        super();
     }
+
+    public int sizeInBytes() {
+        return 1;
+    }
+
 }
diff --git a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/ByteWritable.java
similarity index 62%
copy from hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
copy to pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/ByteWritable.java
index cde5022..2a1fd22 100644
--- a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/ByteWritable.java
@@ -12,17 +12,24 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+package edu.uci.ics.pregelix.example.io;
 
-package edu.uci.ics.hyracks.storage.am.btree.exceptions;
+import edu.uci.ics.pregelix.api.io.WritableSizable;
 
-public class BTreeDuplicateKeyException extends BTreeException {
-    private static final long serialVersionUID = 1L;
+/**
+ * Writable for Byte values.
+ */
+public class ByteWritable extends org.apache.hadoop.io.ByteWritable implements WritableSizable {
 
-    public BTreeDuplicateKeyException(Exception e) {
-        super(e);
+    public ByteWritable(byte value) {
+        super(value);
     }
 
-    public BTreeDuplicateKeyException(String message) {
-        super(message);
+    public ByteWritable() {
+        super();
+    }
+
+    public int sizeInBytes() {
+        return 1;
     }
 }
diff --git a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/BytesWritable.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/BytesWritable.java
new file mode 100644
index 0000000..04a5549
--- /dev/null
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/BytesWritable.java
@@ -0,0 +1,37 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.example.io;
+
+import edu.uci.ics.pregelix.api.io.WritableSizable;
+
+/**
+ * Writable for Bytes values.
+ */
+public class BytesWritable extends org.apache.hadoop.io.BytesWritable implements WritableSizable {
+
+    public BytesWritable(byte[] value) {
+        super(value);
+    }
+
+    public BytesWritable() {
+        super();
+    }
+
+    @Override
+    public int sizeInBytes() {
+        return getLength() + 4; // add the integer size slot
+    }
+
+}
diff --git a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/DoubleWritable.java
similarity index 61%
copy from hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
copy to pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/DoubleWritable.java
index cde5022..ebc7fe4 100644
--- a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/DoubleWritable.java
@@ -13,16 +13,25 @@
  * limitations under the License.
  */
 
-package edu.uci.ics.hyracks.storage.am.btree.exceptions;
+package edu.uci.ics.pregelix.example.io;
 
-public class BTreeDuplicateKeyException extends BTreeException {
-    private static final long serialVersionUID = 1L;
+import edu.uci.ics.pregelix.api.io.WritableSizable;
 
-    public BTreeDuplicateKeyException(Exception e) {
-        super(e);
+/**
+ * Writable for Double values.
+ */
+public class DoubleWritable extends org.apache.hadoop.io.DoubleWritable implements WritableSizable {
+
+    public DoubleWritable(double value) {
+        super(value);
     }
 
-    public BTreeDuplicateKeyException(String message) {
-        super(message);
+    public DoubleWritable() {
+        super();
     }
+
+    public int sizeInBytes() {
+        return 8;
+    }
+
 }
diff --git a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/FloatWritable.java
similarity index 61%
copy from hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
copy to pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/FloatWritable.java
index cde5022..6772b0a 100644
--- a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/FloatWritable.java
@@ -13,16 +13,22 @@
  * limitations under the License.
  */
 
-package edu.uci.ics.hyracks.storage.am.btree.exceptions;
+package edu.uci.ics.pregelix.example.io;
 
-public class BTreeDuplicateKeyException extends BTreeException {
-    private static final long serialVersionUID = 1L;
+import edu.uci.ics.pregelix.api.io.WritableSizable;
 
-    public BTreeDuplicateKeyException(Exception e) {
-        super(e);
+/** A WritableComparable for floats. */
+public class FloatWritable extends org.apache.hadoop.io.FloatWritable implements WritableSizable {
+
+    public FloatWritable(float value) {
+        super(value);
     }
 
-    public BTreeDuplicateKeyException(String message) {
-        super(message);
+    public FloatWritable() {
+        super();
+    }
+
+    public int sizeInBytes() {
+        return 4;
     }
 }
diff --git a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/IntWritable.java
similarity index 62%
copy from hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
copy to pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/IntWritable.java
index cde5022..4944232 100644
--- a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/IntWritable.java
@@ -13,16 +13,23 @@
  * limitations under the License.
  */
 
-package edu.uci.ics.hyracks.storage.am.btree.exceptions;
+package edu.uci.ics.pregelix.example.io;
 
-public class BTreeDuplicateKeyException extends BTreeException {
-    private static final long serialVersionUID = 1L;
+import edu.uci.ics.pregelix.api.io.WritableSizable;
 
-    public BTreeDuplicateKeyException(Exception e) {
-        super(e);
+/** A WritableComparable for ints. */
+public class IntWritable extends org.apache.hadoop.io.IntWritable implements WritableSizable {
+
+    public IntWritable(int value) {
+        super(value);
     }
 
-    public BTreeDuplicateKeyException(String message) {
-        super(message);
+    public IntWritable() {
+        super();
     }
+
+    public int sizeInBytes() {
+        return 4;
+    }
+
 }
diff --git a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/LongWritable.java
similarity index 62%
copy from hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
copy to pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/LongWritable.java
index cde5022..3ecab79 100644
--- a/hyracks/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/exceptions/BTreeDuplicateKeyException.java
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/LongWritable.java
@@ -13,16 +13,23 @@
  * limitations under the License.
  */
 
-package edu.uci.ics.hyracks.storage.am.btree.exceptions;
+package edu.uci.ics.pregelix.example.io;
 
-public class BTreeDuplicateKeyException extends BTreeException {
-    private static final long serialVersionUID = 1L;
+import edu.uci.ics.pregelix.api.io.WritableSizable;
 
-    public BTreeDuplicateKeyException(Exception e) {
-        super(e);
+/** A WritableComparable for longs. */
+public class LongWritable extends org.apache.hadoop.io.LongWritable implements WritableSizable {
+
+    public LongWritable(long value) {
+        super(value);
     }
 
-    public BTreeDuplicateKeyException(String message) {
-        super(message);
+    public LongWritable() {
+        super();
     }
+
+    public int sizeInBytes() {
+        return 8;
+    }
+
 }
diff --git a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/NullWritable.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/NullWritable.java
new file mode 100644
index 0000000..a2f184a
--- /dev/null
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/NullWritable.java
@@ -0,0 +1,89 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.pregelix.example.io;
+
+import java.io.DataInput;
+import java.io.DataOutput;
+import java.io.IOException;
+
+import org.apache.hadoop.io.WritableComparable;
+import org.apache.hadoop.io.WritableComparator;
+
+import edu.uci.ics.pregelix.api.io.WritableSizable;
+
+/** Singleton Writable with no data. */
+@SuppressWarnings("rawtypes")
+public class NullWritable implements WritableComparable, WritableSizable {
+
+    private static final NullWritable THIS = new NullWritable();
+
+    private NullWritable() {
+    } // no public ctor
+
+    /** Returns the single instance of this class. */
+    public static NullWritable get() {
+        return THIS;
+    }
+
+    public String toString() {
+        return "(null)";
+    }
+
+    public int sizeInBytes() {
+        return 0;
+    }
+
+    public int hashCode() {
+        return 0;
+    }
+
+    public int compareTo(Object other) {
+        if (!(other instanceof NullWritable)) {
+            throw new ClassCastException("can't compare " + other.getClass().getName() + " to NullWritable");
+        }
+        return 0;
+    }
+
+    public boolean equals(Object other) {
+        return other instanceof NullWritable;
+    }
+
+    public void readFields(DataInput in) throws IOException {
+    }
+
+    public void write(DataOutput out) throws IOException {
+    }
+
+    /** A Comparator &quot;optimized&quot; for NullWritable. */
+    public static class Comparator extends WritableComparator {
+        public Comparator() {
+            super(NullWritable.class);
+        }
+
+        /**
+         * Compare the buffers in serialized form.
+         */
+        public int compare(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2) {
+            assert 0 == l1;
+            assert 0 == l2;
+            return 0;
+        }
+    }
+
+    static { // register this comparator
+        WritableComparator.define(NullWritable.class, new Comparator());
+    }
+}
diff --git a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/VIntWritable.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/VIntWritable.java
new file mode 100644
index 0000000..94df74f
--- /dev/null
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/VIntWritable.java
@@ -0,0 +1,89 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.pregelix.example.io;
+
+import java.io.DataInput;
+import java.io.DataOutput;
+import java.io.IOException;
+
+import org.apache.hadoop.io.WritableComparable;
+import org.apache.hadoop.io.WritableUtils;
+
+import edu.uci.ics.pregelix.api.io.WritableSizable;
+
+/**
+ * A WritableComparable for integer values stored in variable-length format.
+ * Such values take between one and five bytes. Smaller values take fewer bytes.
+ * 
+ * @see org.apache.hadoop.io.WritableUtils#readVInt(DataInput)
+ */
+@SuppressWarnings("rawtypes")
+public class VIntWritable implements WritableComparable, WritableSizable {
+    private int value;
+
+    public VIntWritable() {
+    }
+
+    public VIntWritable(int value) {
+        set(value);
+    }
+
+    public int sizeInBytes() {
+        return 5;
+    }
+
+    /** Set the value of this VIntWritable. */
+    public void set(int value) {
+        this.value = value;
+    }
+
+    /** Return the value of this VIntWritable. */
+    public int get() {
+        return value;
+    }
+
+    public void readFields(DataInput in) throws IOException {
+        value = WritableUtils.readVInt(in);
+    }
+
+    public void write(DataOutput out) throws IOException {
+        WritableUtils.writeVInt(out, value);
+    }
+
+    /** Returns true iff <code>o</code> is a VIntWritable with the same value. */
+    public boolean equals(Object o) {
+        if (!(o instanceof VIntWritable))
+            return false;
+        VIntWritable other = (VIntWritable) o;
+        return this.value == other.value;
+    }
+
+    public int hashCode() {
+        return value;
+    }
+
+    /** Compares two VIntWritables. */
+    public int compareTo(Object o) {
+        int thisValue = this.value;
+        int thatValue = ((VIntWritable) o).value;
+        return (thisValue < thatValue ? -1 : (thisValue == thatValue ? 0 : 1));
+    }
+
+    public String toString() {
+        return Integer.toString(value);
+    }
+
+}
diff --git a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/VLongWritable.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/VLongWritable.java
index e12d930..ffbbff4 100644
--- a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/VLongWritable.java
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/io/VLongWritable.java
@@ -16,23 +16,21 @@
 package edu.uci.ics.pregelix.example.io;
 
 import java.io.DataInput;
-import java.io.DataOutput;
-import java.io.IOException;
 
 import org.apache.hadoop.io.WritableComparable;
 import org.apache.hadoop.io.WritableComparator;
 
-import edu.uci.ics.pregelix.api.util.SerDeUtils;
+import edu.uci.ics.pregelix.api.io.WritableSizable;
+import edu.uci.ics.pregelix.example.utils.SerDeUtils;
 
 /**
  * A WritableComparable for longs in a variable-length format. Such values take
- * between one and five bytes. Smaller values take fewer bytes.
+ * between one and nine bytes. Smaller values take fewer bytes.
  * 
  * @see org.apache.hadoop.io.WritableUtils#readVLong(DataInput)
  */
 @SuppressWarnings("rawtypes")
-public class VLongWritable implements WritableComparable {
-    private long value;
+public class VLongWritable extends org.apache.hadoop.io.VLongWritable implements WritableSizable {
 
     public VLongWritable() {
     }
@@ -41,57 +39,43 @@
         set(value);
     }
 
-    /** Set the value of this LongWritable. */
-    public void set(long value) {
-        this.value = value;
-    }
+    public int sizeInBytes() {
+        long i = get();
+        if (i >= -112 && i <= 127) {
+            return 1;
+        }
 
-    /** Return the value of this LongWritable. */
-    public long get() {
-        return value;
-    }
+        int len = -112;
+        if (i < 0) {
+            i ^= -1L; // take one's complement'
+            len = -120;
+        }
 
-    public void readFields(DataInput in) throws IOException {
-        value = SerDeUtils.readVLong(in);
-    }
+        long tmp = i;
+        while (tmp != 0) {
+            tmp = tmp >> 8;
+            len--;
+        }
 
-    public void write(DataOutput out) throws IOException {
-        SerDeUtils.writeVLong(out, value);
-    }
-
-    /** Returns true iff <code>o</code> is a VLongWritable with the same value. */
-    public boolean equals(Object o) {
-        if (!(o instanceof VLongWritable))
-            return false;
-        VLongWritable other = (VLongWritable) o;
-        return this.value == other.value;
-    }
-
-    public int hashCode() {
-        return (int) value;
-    }
-
-    /** Compares two VLongWritables. */
-    public int compareTo(Object o) {
-        long thisValue = this.value;
-        long thatValue = ((VLongWritable) o).value;
-        return (thisValue < thatValue ? -1 : (thisValue == thatValue ? 0 : 1));
-    }
-
-    public String toString() {
-        return Long.toString(value);
+        len = (len < -120) ? -(len + 120) : -(len + 112);
+        return len + 1;
     }
 
     /** A Comparator optimized for LongWritable. */
     public static class Comparator extends WritableComparator {
+
         public Comparator() {
             super(VLongWritable.class);
         }
 
         public int compare(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2) {
-            long thisValue = SerDeUtils.readVLong(b1, s1, l1);
-            long thatValue = SerDeUtils.readVLong(b2, s2, l2);
-            return (thisValue < thatValue ? -1 : (thisValue == thatValue ? 0 : 1));
+            try {
+                long thisValue = SerDeUtils.readVLong(b1, s1, l1);
+                long thatValue = SerDeUtils.readVLong(b2, s2, l2);
+                return (thisValue < thatValue ? -1 : (thisValue == thatValue ? 0 : 1));
+            } catch (Exception e) {
+                throw new IllegalStateException(e);
+            }
         }
     }
 
diff --git a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/maximalclique/AdjacencyListWritable.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/maximalclique/AdjacencyListWritable.java
index 0a58c00..dd86a45 100644
--- a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/maximalclique/AdjacencyListWritable.java
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/maximalclique/AdjacencyListWritable.java
@@ -23,14 +23,13 @@
 import java.util.Set;
 import java.util.TreeSet;
 
-import org.apache.hadoop.io.Writable;
-
+import edu.uci.ics.pregelix.api.io.WritableSizable;
 import edu.uci.ics.pregelix.example.io.VLongWritable;
 
 /**
  * The adjacency list contains <src, list-of-neighbors>
  */
-public class AdjacencyListWritable implements Writable {
+public class AdjacencyListWritable implements WritableSizable {
 
     private VLongWritable sourceVertex = new VLongWritable();
     private Set<VLongWritable> destinationVertexes = new TreeSet<VLongWritable>();
@@ -96,4 +95,13 @@
         return destinationVertexes.contains(v);
     }
 
+    @Override
+    public int sizeInBytes() {
+        int size = 4; // the size of list bytes
+        for (VLongWritable dest : destinationVertexes) {
+            size += dest.sizeInBytes();
+        }
+        return size;
+    }
+
 }
diff --git a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/utils/SerDeUtils.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/utils/SerDeUtils.java
new file mode 100644
index 0000000..2800187
--- /dev/null
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/utils/SerDeUtils.java
@@ -0,0 +1,56 @@
+package edu.uci.ics.pregelix.example.utils;
+
+import java.io.IOException;
+
+public class SerDeUtils {
+
+    /**
+     * Reads a zero-compressed encoded long from input stream and returns it.
+     * 
+     * @param stream
+     *            Binary input stream
+     * @throws java.io.IOException
+     * @return deserialized long from stream.
+     */
+    public static long readVLong(byte[] data, int start, int length) throws IOException {
+        byte firstByte = data[start];
+        int len = decodeVIntSize(firstByte);
+        if (len == 1) {
+            return firstByte;
+        }
+        long i = 0;
+        for (int idx = 0; idx < len - 1; idx++) {
+            i = i << 8;
+            i = i | (data[++start] & 0xFF);
+        }
+        return (isNegativeVInt(firstByte) ? (i ^ -1L) : i);
+    }
+
+    /**
+     * Parse the first byte of a vint/vlong to determine the number of bytes
+     * 
+     * @param value
+     *            the first byte of the vint/vlong
+     * @return the total number of bytes (1 to 9)
+     */
+    public static int decodeVIntSize(byte value) {
+        if (value >= -112) {
+            return 1;
+        } else if (value < -120) {
+            return -119 - value;
+        }
+        return -111 - value;
+    }
+
+    /**
+     * Given the first byte of a vint/vlong, determine the sign
+     * 
+     * @param value
+     *            the first byte
+     * @return is the value negative
+     */
+    public static boolean isNegativeVInt(byte value) {
+        return value < -120 || (value >= -112 && value < 0);
+    }
+
+}
diff --git a/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/FailureRecoveryConnectedComponentsTest.java b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/FailureRecoveryConnectedComponentsTest.java
new file mode 100644
index 0000000..efc7bcc
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/FailureRecoveryConnectedComponentsTest.java
@@ -0,0 +1,91 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.example;
+
+import java.io.File;
+
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
+import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
+import org.junit.Test;
+
+import edu.uci.ics.pregelix.api.graph.Vertex;
+import edu.uci.ics.pregelix.api.job.PregelixJob;
+import edu.uci.ics.pregelix.api.util.ConservativeCheckpointHook;
+import edu.uci.ics.pregelix.api.util.DefaultVertexPartitioner;
+import edu.uci.ics.pregelix.core.driver.Driver;
+import edu.uci.ics.pregelix.core.util.PregelixHyracksIntegrationUtil;
+import edu.uci.ics.pregelix.example.ConnectedComponentsVertex.SimpleConnectedComponentsVertexOutputFormat;
+import edu.uci.ics.pregelix.example.data.VLongNormalizedKeyComputer;
+import edu.uci.ics.pregelix.example.inputformat.TextConnectedComponentsInputFormat;
+import edu.uci.ics.pregelix.example.util.TestCluster;
+import edu.uci.ics.pregelix.example.util.TestUtils;
+
+/**
+ * @author yingyib
+ */
+public class FailureRecoveryConnectedComponentsTest {
+    private static String INPUTPATH = "data/webmapcomplex";
+    private static String OUTPUTPAH = "actual/result";
+    private static String EXPECTEDPATH = "src/test/resources/expected/ConnectedComponentsRealComplex2";
+
+    @Test
+    public void test() throws Exception {
+        TestCluster testCluster = new TestCluster();
+        try {
+            PregelixJob job = new PregelixJob(ConnectedComponentsVertex.class.getName());
+            job.setVertexClass(ConnectedComponentsVertex.class);
+            job.setVertexClass(ConnectedComponentsVertex.class);
+            job.setVertexInputFormatClass(TextConnectedComponentsInputFormat.class);
+            job.setVertexOutputFormatClass(SimpleConnectedComponentsVertexOutputFormat.class);
+            job.setMessageCombinerClass(ConnectedComponentsVertex.SimpleMinCombiner.class);
+            job.setNoramlizedKeyComputerClass(VLongNormalizedKeyComputer.class);
+            job.setVertexPartitionerClass(DefaultVertexPartitioner.class);
+            job.setDynamicVertexValueSize(true);
+            FileInputFormat.setInputPaths(job, INPUTPATH);
+            FileOutputFormat.setOutputPath(job, new Path(OUTPUTPAH));
+            job.getConfiguration().setLong(PregelixJob.NUM_VERTICE, 23);
+            job.setCheckpointHook(ConservativeCheckpointHook.class);
+
+            testCluster.setUp();
+            Driver driver = new Driver(PageRankVertex.class);
+            Thread thread = new Thread(new Runnable() {
+
+                @Override
+                public void run() {
+                    try {
+                        synchronized (this) {
+                            while (Vertex.getSuperstep() <= 5) {
+                                this.wait(200);
+                            }
+                            PregelixHyracksIntegrationUtil.shutdownNC1();
+                        }
+                    } catch (Exception e) {
+                        throw new IllegalStateException(e);
+                    }
+                }
+            });
+            thread.start();
+            driver.runJob(job, "127.0.0.1", PregelixHyracksIntegrationUtil.TEST_HYRACKS_CC_CLIENT_PORT);
+
+            TestUtils.compareWithResultDir(new File(EXPECTEDPATH), new File(OUTPUTPAH));
+        } catch (Exception e) {
+            PregelixHyracksIntegrationUtil.shutdownNC2();
+            testCluster.cleanupHDFS();
+            throw e;
+        }
+    }
+
+}
diff --git a/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/FailureRecoveryInnerJoinTest.java b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/FailureRecoveryInnerJoinTest.java
new file mode 100644
index 0000000..ff1e29f
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/FailureRecoveryInnerJoinTest.java
@@ -0,0 +1,90 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.example;
+
+import java.io.File;
+
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
+import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
+import org.junit.Test;
+
+import edu.uci.ics.pregelix.api.graph.Vertex;
+import edu.uci.ics.pregelix.api.job.PregelixJob;
+import edu.uci.ics.pregelix.api.util.ConservativeCheckpointHook;
+import edu.uci.ics.pregelix.core.base.IDriver.Plan;
+import edu.uci.ics.pregelix.core.driver.Driver;
+import edu.uci.ics.pregelix.core.util.PregelixHyracksIntegrationUtil;
+import edu.uci.ics.pregelix.example.PageRankVertex.SimplePageRankVertexOutputFormat;
+import edu.uci.ics.pregelix.example.data.VLongNormalizedKeyComputer;
+import edu.uci.ics.pregelix.example.inputformat.TextPageRankInputFormat;
+import edu.uci.ics.pregelix.example.util.TestCluster;
+import edu.uci.ics.pregelix.example.util.TestUtils;
+
+/**
+ * @author yingyib
+ */
+public class FailureRecoveryInnerJoinTest {
+    private static String INPUTPATH = "data/webmap";
+    private static String OUTPUTPAH = "actual/result";
+    private static String EXPECTEDPATH = "src/test/resources/expected/PageRankReal2";
+
+    @Test
+    public void test() throws Exception {
+        TestCluster testCluster = new TestCluster();
+
+        try {
+            PregelixJob job = new PregelixJob(PageRankVertex.class.getName());
+            job.setVertexClass(PageRankVertex.class);
+            job.setVertexInputFormatClass(TextPageRankInputFormat.class);
+            job.setVertexOutputFormatClass(SimplePageRankVertexOutputFormat.class);
+            job.setMessageCombinerClass(PageRankVertex.SimpleSumCombiner.class);
+            job.setNoramlizedKeyComputerClass(VLongNormalizedKeyComputer.class);
+            FileInputFormat.setInputPaths(job, INPUTPATH);
+            FileOutputFormat.setOutputPath(job, new Path(OUTPUTPAH));
+            job.getConfiguration().setLong(PregelixJob.NUM_VERTICE, 20);
+            job.setCheckpointHook(ConservativeCheckpointHook.class);
+
+            testCluster.setUp();
+            Driver driver = new Driver(PageRankVertex.class);
+            Thread thread = new Thread(new Runnable() {
+
+                @Override
+                public void run() {
+                    try {
+                        synchronized (this) {
+                            while (Vertex.getSuperstep() <= 5) {
+                                this.wait(200);
+                            }
+                            PregelixHyracksIntegrationUtil.shutdownNC1();
+                        }
+                    } catch (Exception e) {
+                        throw new IllegalStateException(e);
+                    }
+                }
+            });
+            thread.start();
+            driver.runJob(job, Plan.INNER_JOIN, "127.0.0.1",
+                    PregelixHyracksIntegrationUtil.TEST_HYRACKS_CC_CLIENT_PORT, false);
+
+            TestUtils.compareWithResultDir(new File(EXPECTEDPATH), new File(OUTPUTPAH));
+        } catch (Exception e) {
+            PregelixHyracksIntegrationUtil.shutdownNC2();
+            testCluster.cleanupHDFS();
+            throw e;
+        }
+    }
+
+}
diff --git a/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/FailureRecoveryTest.java b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/FailureRecoveryTest.java
new file mode 100644
index 0000000..3fdaf15
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/FailureRecoveryTest.java
@@ -0,0 +1,88 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.example;
+
+import java.io.File;
+
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
+import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
+import org.junit.Test;
+
+import edu.uci.ics.pregelix.api.graph.Vertex;
+import edu.uci.ics.pregelix.api.job.PregelixJob;
+import edu.uci.ics.pregelix.api.util.ConservativeCheckpointHook;
+import edu.uci.ics.pregelix.core.driver.Driver;
+import edu.uci.ics.pregelix.core.util.PregelixHyracksIntegrationUtil;
+import edu.uci.ics.pregelix.example.PageRankVertex.SimplePageRankVertexOutputFormat;
+import edu.uci.ics.pregelix.example.data.VLongNormalizedKeyComputer;
+import edu.uci.ics.pregelix.example.inputformat.TextPageRankInputFormat;
+import edu.uci.ics.pregelix.example.util.TestCluster;
+import edu.uci.ics.pregelix.example.util.TestUtils;
+
+/**
+ * @author yingyib
+ */
+public class FailureRecoveryTest {
+    private static String INPUTPATH = "data/webmap";
+    private static String OUTPUTPAH = "actual/result";
+    private static String EXPECTEDPATH = "src/test/resources/expected/PageRankReal2";
+
+    @Test
+    public void test() throws Exception {
+        TestCluster testCluster = new TestCluster();
+
+        try {
+            PregelixJob job = new PregelixJob(PageRankVertex.class.getName());
+            job.setVertexClass(PageRankVertex.class);
+            job.setVertexInputFormatClass(TextPageRankInputFormat.class);
+            job.setVertexOutputFormatClass(SimplePageRankVertexOutputFormat.class);
+            job.setMessageCombinerClass(PageRankVertex.SimpleSumCombiner.class);
+            job.setNoramlizedKeyComputerClass(VLongNormalizedKeyComputer.class);
+            FileInputFormat.setInputPaths(job, INPUTPATH);
+            FileOutputFormat.setOutputPath(job, new Path(OUTPUTPAH));
+            job.getConfiguration().setLong(PregelixJob.NUM_VERTICE, 20);
+            job.setCheckpointHook(ConservativeCheckpointHook.class);
+
+            testCluster.setUp();
+            Driver driver = new Driver(PageRankVertex.class);
+            Thread thread = new Thread(new Runnable() {
+
+                @Override
+                public void run() {
+                    try {
+                        synchronized (this) {
+                            while (Vertex.getSuperstep() <= 5) {
+                                this.wait(200);
+                            }
+                            PregelixHyracksIntegrationUtil.shutdownNC1();
+                        }
+                    } catch (Exception e) {
+                        throw new IllegalStateException(e);
+                    }
+                }
+            });
+            thread.start();
+            driver.runJob(job, "127.0.0.1", PregelixHyracksIntegrationUtil.TEST_HYRACKS_CC_CLIENT_PORT);
+
+            TestUtils.compareWithResultDir(new File(EXPECTEDPATH), new File(OUTPUTPAH));
+        } catch (Exception e) {
+            PregelixHyracksIntegrationUtil.shutdownNC2();
+            testCluster.cleanupHDFS();
+            throw e;
+        }
+    }
+
+}
diff --git a/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/FailureRecoveryWithoutCheckpointTest.java b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/FailureRecoveryWithoutCheckpointTest.java
new file mode 100644
index 0000000..e006ccd
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/FailureRecoveryWithoutCheckpointTest.java
@@ -0,0 +1,86 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.example;
+
+import java.io.File;
+
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
+import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
+import org.junit.Test;
+
+import edu.uci.ics.pregelix.api.graph.Vertex;
+import edu.uci.ics.pregelix.api.job.PregelixJob;
+import edu.uci.ics.pregelix.core.driver.Driver;
+import edu.uci.ics.pregelix.core.util.PregelixHyracksIntegrationUtil;
+import edu.uci.ics.pregelix.example.PageRankVertex.SimplePageRankVertexOutputFormat;
+import edu.uci.ics.pregelix.example.data.VLongNormalizedKeyComputer;
+import edu.uci.ics.pregelix.example.inputformat.TextPageRankInputFormat;
+import edu.uci.ics.pregelix.example.util.TestCluster;
+import edu.uci.ics.pregelix.example.util.TestUtils;
+
+/**
+ * @author yingyib
+ */
+public class FailureRecoveryWithoutCheckpointTest {
+    private static String INPUTPATH = "data/webmap";
+    private static String OUTPUTPAH = "actual/result";
+    private static String EXPECTEDPATH = "src/test/resources/expected/PageRankReal2";
+
+    @Test
+    public void test() throws Exception {
+        TestCluster testCluster = new TestCluster();
+
+        try {
+            PregelixJob job = new PregelixJob(PageRankVertex.class.getName());
+            job.setVertexClass(PageRankVertex.class);
+            job.setVertexInputFormatClass(TextPageRankInputFormat.class);
+            job.setVertexOutputFormatClass(SimplePageRankVertexOutputFormat.class);
+            job.setMessageCombinerClass(PageRankVertex.SimpleSumCombiner.class);
+            job.setNoramlizedKeyComputerClass(VLongNormalizedKeyComputer.class);
+            FileInputFormat.setInputPaths(job, INPUTPATH);
+            FileOutputFormat.setOutputPath(job, new Path(OUTPUTPAH));
+            job.getConfiguration().setLong(PregelixJob.NUM_VERTICE, 20);
+
+            testCluster.setUp();
+            Driver driver = new Driver(PageRankVertex.class);
+            Thread thread = new Thread(new Runnable() {
+
+                @Override
+                public void run() {
+                    try {
+                        synchronized (this) {
+                            while (Vertex.getSuperstep() <= 5) {
+                                this.wait(200);
+                            }
+                            PregelixHyracksIntegrationUtil.shutdownNC1();
+                        }
+                    } catch (Exception e) {
+                        throw new IllegalStateException(e);
+                    }
+                }
+            });
+            thread.start();
+            driver.runJob(job, "127.0.0.1", PregelixHyracksIntegrationUtil.TEST_HYRACKS_CC_CLIENT_PORT);
+
+            TestUtils.compareWithResultDir(new File(EXPECTEDPATH), new File(OUTPUTPAH));
+        } catch (Exception e) {
+            PregelixHyracksIntegrationUtil.shutdownNC2();
+            testCluster.cleanupHDFS();
+            throw e;
+        }
+    }
+
+}
diff --git a/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/FailureVertex.java b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/FailureVertex.java
new file mode 100644
index 0000000..d2464c1
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/FailureVertex.java
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.example;
+
+import java.util.Iterator;
+
+import org.apache.hadoop.io.FloatWritable;
+
+import edu.uci.ics.pregelix.api.graph.Vertex;
+import edu.uci.ics.pregelix.example.io.VLongWritable;
+
+/**
+ * @author yingyib
+ */
+public class FailureVertex extends Vertex<VLongWritable, VLongWritable, FloatWritable, VLongWritable> {
+
+    @Override
+    public void compute(Iterator<VLongWritable> msgIterator) throws Exception {
+        if (getVertexId().get() == 10) {
+            throw new IllegalStateException("This job is going to fail");
+        }
+    }
+
+}
diff --git a/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/FailureVertexTest.java b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/FailureVertexTest.java
new file mode 100644
index 0000000..a2d32c0
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/FailureVertexTest.java
@@ -0,0 +1,70 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.example;
+
+import junit.framework.Assert;
+
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
+import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
+import org.junit.Test;
+
+import edu.uci.ics.pregelix.api.job.PregelixJob;
+import edu.uci.ics.pregelix.core.driver.Driver;
+import edu.uci.ics.pregelix.core.util.PregelixHyracksIntegrationUtil;
+import edu.uci.ics.pregelix.example.ConnectedComponentsVertex;
+import edu.uci.ics.pregelix.example.ConnectedComponentsVertex.SimpleConnectedComponentsVertexOutputFormat;
+import edu.uci.ics.pregelix.example.FailureVertex;
+import edu.uci.ics.pregelix.example.data.VLongNormalizedKeyComputer;
+import edu.uci.ics.pregelix.example.inputformat.TextPageRankInputFormat;
+import edu.uci.ics.pregelix.example.util.TestCluster;
+
+/**
+ * This test case tests the error message propagation.
+ * 
+ * @author yingyib
+ */
+public class FailureVertexTest {
+
+    private static String INPUT_PATH = "data/webmapcomplex";
+    private static String OUTPUT_PATH = "actual/resultcomplex";
+
+    @Test
+    public void test() throws Exception {
+        TestCluster testCluster = new TestCluster();
+        try {
+            PregelixJob job = new PregelixJob(FailureVertex.class.getSimpleName());
+            job.setVertexClass(FailureVertex.class);
+            job.setVertexInputFormatClass(TextPageRankInputFormat.class);
+            job.setVertexOutputFormatClass(SimpleConnectedComponentsVertexOutputFormat.class);
+            job.setMessageCombinerClass(ConnectedComponentsVertex.SimpleMinCombiner.class);
+            job.setNoramlizedKeyComputerClass(VLongNormalizedKeyComputer.class);
+            job.setDynamicVertexValueSize(true);
+
+            FileInputFormat.setInputPaths(job, INPUT_PATH);
+            FileOutputFormat.setOutputPath(job, new Path(OUTPUT_PATH));
+            job.getConfiguration().setLong(PregelixJob.NUM_VERTICE, 23);
+
+            Driver driver = new Driver(FailureVertex.class);
+            testCluster.setUp();
+            driver.runJob(job, "127.0.0.1", PregelixHyracksIntegrationUtil.TEST_HYRACKS_CC_CLIENT_PORT);
+        } catch (Exception e) {
+            Assert.assertTrue(e.toString().contains("This job is going to fail"));
+        } finally {
+            testCluster.tearDown();
+        }
+    }
+
+}
diff --git a/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/JobConcatenationTest.java b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/JobConcatenationTest.java
new file mode 100644
index 0000000..dc7a28d
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/JobConcatenationTest.java
@@ -0,0 +1,86 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.example;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
+import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
+import org.junit.Test;
+
+import edu.uci.ics.pregelix.api.job.PregelixJob;
+import edu.uci.ics.pregelix.api.util.ConservativeCheckpointHook;
+import edu.uci.ics.pregelix.core.driver.Driver;
+import edu.uci.ics.pregelix.core.util.PregelixHyracksIntegrationUtil;
+import edu.uci.ics.pregelix.example.PageRankVertex.SimplePageRankVertexOutputFormat;
+import edu.uci.ics.pregelix.example.data.VLongNormalizedKeyComputer;
+import edu.uci.ics.pregelix.example.inputformat.TextPageRankInputFormat;
+import edu.uci.ics.pregelix.example.util.TestCluster;
+import edu.uci.ics.pregelix.example.util.TestUtils;
+
+/**
+ * @author yingyib
+ */
+public class JobConcatenationTest {
+
+    private static String INPUTPATH = "data/webmap";
+    private static String OUTPUTPAH = "actual/result";
+    private static String EXPECTEDPATH = "src/test/resources/expected/PageRankReal";
+
+    @Test
+    public void test() throws Exception {
+        TestCluster testCluster = new TestCluster();
+
+        try {
+            List<PregelixJob> jobs = new ArrayList<PregelixJob>();
+            PregelixJob job1 = new PregelixJob(PageRankVertex.class.getName());
+            job1.setVertexClass(PageRankVertex.class);
+            job1.setVertexInputFormatClass(TextPageRankInputFormat.class);
+            job1.setVertexOutputFormatClass(SimplePageRankVertexOutputFormat.class);
+            job1.setMessageCombinerClass(PageRankVertex.SimpleSumCombiner.class);
+            job1.setNoramlizedKeyComputerClass(VLongNormalizedKeyComputer.class);
+            FileInputFormat.setInputPaths(job1, INPUTPATH);
+            job1.getConfiguration().setLong(PregelixJob.NUM_VERTICE, 20);
+            job1.setCheckpointHook(ConservativeCheckpointHook.class);
+
+            PregelixJob job2 = new PregelixJob(PageRankVertex.class.getName());
+            job2.setVertexClass(PageRankVertex.class);
+            job2.setVertexInputFormatClass(TextPageRankInputFormat.class);
+            job2.setVertexOutputFormatClass(SimplePageRankVertexOutputFormat.class);
+            job2.setMessageCombinerClass(PageRankVertex.SimpleSumCombiner.class);
+            job2.setNoramlizedKeyComputerClass(VLongNormalizedKeyComputer.class);
+            FileOutputFormat.setOutputPath(job2, new Path(OUTPUTPAH));
+            job2.getConfiguration().setLong(PregelixJob.NUM_VERTICE, 20);
+            job2.setCheckpointHook(ConservativeCheckpointHook.class);
+
+            jobs.add(job1);
+            jobs.add(job2);
+
+            testCluster.setUp();
+            Driver driver = new Driver(PageRankVertex.class);
+            driver.runJobs(jobs, "127.0.0.1", PregelixHyracksIntegrationUtil.TEST_HYRACKS_CC_CLIENT_PORT);
+
+            TestUtils.compareWithResultDir(new File(EXPECTEDPATH), new File(OUTPUTPAH));
+        } catch (Exception e) {
+            throw e;
+        } finally {
+            testCluster.tearDown();
+        }
+    }
+
+}
diff --git a/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/OverflowAggregatorTest.java b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/OverflowAggregatorTest.java
new file mode 100644
index 0000000..474d0a6
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/OverflowAggregatorTest.java
@@ -0,0 +1,79 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.example;
+
+import java.io.File;
+
+import junit.framework.Assert;
+
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.io.Text;
+import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
+import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
+import org.junit.Test;
+
+import edu.uci.ics.pregelix.api.job.PregelixJob;
+import edu.uci.ics.pregelix.api.util.BspUtils;
+import edu.uci.ics.pregelix.core.driver.Driver;
+import edu.uci.ics.pregelix.core.util.PregelixHyracksIntegrationUtil;
+import edu.uci.ics.pregelix.dataflow.util.IterationUtils;
+import edu.uci.ics.pregelix.example.PageRankVertex.SimplePageRankVertexOutputFormat;
+import edu.uci.ics.pregelix.example.aggregator.OverflowAggregator;
+import edu.uci.ics.pregelix.example.data.VLongNormalizedKeyComputer;
+import edu.uci.ics.pregelix.example.inputformat.TextPageRankInputFormat;
+import edu.uci.ics.pregelix.example.util.TestCluster;
+import edu.uci.ics.pregelix.example.util.TestUtils;
+
+/**
+ * @author yingyib
+ */
+public class OverflowAggregatorTest {
+
+    private static String INPUTPATH = "data/webmap";
+    private static String OUTPUTPAH = "actual/result";
+    private static String EXPECTEDPATH = "src/test/resources/expected/PageRankReal";
+
+    @Test
+    public void test() throws Exception {
+        TestCluster testCluster = new TestCluster();
+
+        try {
+            PregelixJob job = new PregelixJob(PageRankVertex.class.getName());
+            job.setVertexClass(PageRankVertex.class);
+            job.setVertexInputFormatClass(TextPageRankInputFormat.class);
+            job.setVertexOutputFormatClass(SimplePageRankVertexOutputFormat.class);
+            job.setMessageCombinerClass(PageRankVertex.SimpleSumCombiner.class);
+            job.setNoramlizedKeyComputerClass(VLongNormalizedKeyComputer.class);
+            FileInputFormat.setInputPaths(job, INPUTPATH);
+            FileOutputFormat.setOutputPath(job, new Path(OUTPUTPAH));
+            job.getConfiguration().setLong(PregelixJob.NUM_VERTICE, 20);
+            job.setGlobalAggregatorClass(OverflowAggregator.class);
+
+            testCluster.setUp();
+            Driver driver = new Driver(PageRankVertex.class);
+            driver.runJob(job, "127.0.0.1", PregelixHyracksIntegrationUtil.TEST_HYRACKS_CC_CLIENT_PORT);
+
+            TestUtils.compareWithResultDir(new File(EXPECTEDPATH), new File(OUTPUTPAH));
+            Text text = (Text) IterationUtils.readGlobalAggregateValue(job.getConfiguration(),
+                    BspUtils.getJobId(job.getConfiguration()));
+            Assert.assertEquals(text.getLength(), 20 * 32767);
+        } catch (Exception e) {
+            throw e;
+        } finally {
+            testCluster.tearDown();
+        }
+    }
+
+}
diff --git a/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/aggregator/OverflowAggregator.java b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/aggregator/OverflowAggregator.java
new file mode 100644
index 0000000..34b8b51
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/aggregator/OverflowAggregator.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.example.aggregator;
+
+import org.apache.hadoop.io.FloatWritable;
+import org.apache.hadoop.io.Text;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.pregelix.api.graph.GlobalAggregator;
+import edu.uci.ics.pregelix.api.graph.Vertex;
+import edu.uci.ics.pregelix.example.io.DoubleWritable;
+import edu.uci.ics.pregelix.example.io.VLongWritable;
+
+/**
+ * Test the case where the global aggregate's state is bloated
+ * 
+ * @author yingyib
+ */
+public class OverflowAggregator extends
+        GlobalAggregator<VLongWritable, DoubleWritable, FloatWritable, DoubleWritable, Text, Text> {
+
+    private int textLength = 0;
+    private int inc = 32767;
+
+    @Override
+    public void init() {
+        textLength = 0;
+    }
+
+    @Override
+    public void step(Vertex<VLongWritable, DoubleWritable, FloatWritable, DoubleWritable> v)
+            throws HyracksDataException {
+        textLength += inc;
+    }
+
+    @Override
+    public void step(Text partialResult) {
+        textLength += partialResult.getLength();
+    }
+
+    @Override
+    public Text finishPartial() {
+        byte[] partialResult = new byte[textLength];
+        for (int i = 0; i < partialResult.length; i++) {
+            partialResult[i] = 'a';
+        }
+        Text text = new Text();
+        text.set(partialResult);
+        return text;
+    }
+
+    @Override
+    public Text finishFinal() {
+        byte[] result = new byte[textLength];
+        for (int i = 0; i < result.length; i++) {
+            result[i] = 'a';
+        }
+        Text text = new Text();
+        text.set(result);
+        return text;
+    }
+
+}
diff --git a/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/jobgen/JobGenerator.java b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/jobgen/JobGenerator.java
index 15117a1..f6857fe 100644
--- a/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/jobgen/JobGenerator.java
+++ b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/jobgen/JobGenerator.java
@@ -23,11 +23,17 @@
 import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
 
 import edu.uci.ics.pregelix.api.job.PregelixJob;
+import edu.uci.ics.pregelix.api.util.ConservativeCheckpointHook;
 import edu.uci.ics.pregelix.api.util.DefaultVertexPartitioner;
 import edu.uci.ics.pregelix.example.ConnectedComponentsVertex;
 import edu.uci.ics.pregelix.example.ConnectedComponentsVertex.SimpleConnectedComponentsVertexOutputFormat;
+import edu.uci.ics.pregelix.example.EarlyTerminationVertex;
+import edu.uci.ics.pregelix.example.EarlyTerminationVertex.SimpleEarlyTerminattionVertexOutputFormat;
 import edu.uci.ics.pregelix.example.GraphMutationVertex;
 import edu.uci.ics.pregelix.example.GraphMutationVertex.SimpleGraphMutationVertexOutputFormat;
+import edu.uci.ics.pregelix.example.MessageOverflowFixedsizeVertex;
+import edu.uci.ics.pregelix.example.MessageOverflowVertex;
+import edu.uci.ics.pregelix.example.MessageOverflowVertex.SimpleMessageOverflowVertexOutputFormat;
 import edu.uci.ics.pregelix.example.PageRankVertex;
 import edu.uci.ics.pregelix.example.PageRankVertex.SimplePageRankVertexOutputFormat;
 import edu.uci.ics.pregelix.example.PageRankVertex.SimulatedPageRankVertexInputFormat;
@@ -71,6 +77,7 @@
         FileInputFormat.setInputPaths(job, HDFS_INPUTPATH);
         FileOutputFormat.setOutputPath(job, new Path(HDFS_OUTPUTPAH));
         job.getConfiguration().setLong(PregelixJob.NUM_VERTICE, 20);
+        job.setCheckpointHook(ConservativeCheckpointHook.class);
         job.getConfiguration().writeXml(new FileOutputStream(new File(outputPath)));
     }
 
@@ -85,6 +92,7 @@
         FileInputFormat.setInputPaths(job, HDFS_INPUTPATH2);
         FileOutputFormat.setOutputPath(job, new Path(HDFS_OUTPUTPAH2));
         job.getConfiguration().setLong(PregelixJob.NUM_VERTICE, 23);
+        job.setCheckpointHook(ConservativeCheckpointHook.class);
         job.getConfiguration().writeXml(new FileOutputStream(new File(outputPath)));
     }
 
@@ -111,6 +119,7 @@
         FileInputFormat.setInputPaths(job, HDFS_INPUTPATH);
         FileOutputFormat.setOutputPath(job, new Path(HDFS_OUTPUTPAH));
         job.getConfiguration().setLong(PregelixJob.NUM_VERTICE, 20);
+        job.setCheckpointHook(ConservativeCheckpointHook.class);
         job.getConfiguration().writeXml(new FileOutputStream(new File(outputPath)));
     }
 
@@ -121,6 +130,7 @@
         job.setVertexOutputFormatClass(SimpleConnectedComponentsVertexOutputFormat.class);
         job.setMessageCombinerClass(ConnectedComponentsVertex.SimpleMinCombiner.class);
         job.setNoramlizedKeyComputerClass(VLongNormalizedKeyComputer.class);
+        job.setDynamicVertexValueSize(true);
         FileInputFormat.setInputPaths(job, HDFS_INPUTPATH);
         FileOutputFormat.setOutputPath(job, new Path(HDFS_OUTPUTPAH));
         job.getConfiguration().setLong(PregelixJob.NUM_VERTICE, 20);
@@ -135,6 +145,7 @@
         job.setMessageCombinerClass(ConnectedComponentsVertex.SimpleMinCombiner.class);
         job.setNoramlizedKeyComputerClass(VLongNormalizedKeyComputer.class);
         job.setVertexPartitionerClass(DefaultVertexPartitioner.class);
+        job.setDynamicVertexValueSize(true);
         FileInputFormat.setInputPaths(job, HDFS_INPUTPATH2);
         FileOutputFormat.setOutputPath(job, new Path(HDFS_OUTPUTPAH2));
         job.getConfiguration().setLong(PregelixJob.NUM_VERTICE, 23);
@@ -233,7 +244,7 @@
         job.setVertexInputFormatClass(TextMaximalCliqueInputFormat.class);
         job.setVertexOutputFormatClass(MaximalCliqueVertexOutputFormat.class);
         job.setNoramlizedKeyComputerClass(VLongNormalizedKeyComputer.class);
-        job.setMutationOrVariableSizedUpdateHeavy(true);
+        job.setLSMStorage(true);
         FileInputFormat.setInputPaths(job, HDFS_INPUTPATH3);
         FileOutputFormat.setOutputPath(job, new Path(HDFS_OUTPUTPAH3));
         job.getConfiguration().writeXml(new FileOutputStream(new File(outputPath)));
@@ -247,7 +258,7 @@
         job.setVertexInputFormatClass(TextMaximalCliqueInputFormat.class);
         job.setVertexOutputFormatClass(MaximalCliqueVertexOutputFormat.class);
         job.setNoramlizedKeyComputerClass(VLongNormalizedKeyComputer.class);
-        job.setMutationOrVariableSizedUpdateHeavy(true);
+        job.setLSMStorage(true);
         FileInputFormat.setInputPaths(job, HDFS_INPUTPATH4);
         FileOutputFormat.setOutputPath(job, new Path(HDFS_OUTPUTPAH3));
         job.getConfiguration().writeXml(new FileOutputStream(new File(outputPath)));
@@ -262,7 +273,7 @@
         job.setVertexOutputFormatClass(MaximalCliqueVertexOutputFormat.class);
         job.setNoramlizedKeyComputerClass(VLongNormalizedKeyComputer.class);
         job.setVertexPartitionerClass(DefaultVertexPartitioner.class);
-        job.setMutationOrVariableSizedUpdateHeavy(true);
+        job.setLSMStorage(true);
         FileInputFormat.setInputPaths(job, HDFS_INPUTPATH5);
         FileOutputFormat.setOutputPath(job, new Path(HDFS_OUTPUTPAH3));
         job.getConfiguration().writeXml(new FileOutputStream(new File(outputPath)));
@@ -280,6 +291,59 @@
         job.getConfiguration().writeXml(new FileOutputStream(new File(outputPath)));
     }
 
+    private static void generateMessageOverflowFixedsizeJob(String jobName, String outputPath) throws IOException {
+        PregelixJob job = new PregelixJob(jobName);
+        job.setVertexClass(MessageOverflowFixedsizeVertex.class);
+        job.setVertexInputFormatClass(TextPageRankInputFormat.class);
+        job.setVertexOutputFormatClass(MessageOverflowFixedsizeVertex.SimpleMessageOverflowVertexOutputFormat.class);
+        job.setFrameSize(2048);
+        FileInputFormat.setInputPaths(job, HDFS_INPUTPATH);
+        FileOutputFormat.setOutputPath(job, new Path(HDFS_OUTPUTPAH));
+        job.getConfiguration().setLong(PregelixJob.NUM_VERTICE, 20);
+        job.getConfiguration().writeXml(new FileOutputStream(new File(outputPath)));
+    }
+
+    private static void generateMessageOverflowJob(String jobName, String outputPath) throws IOException {
+        PregelixJob job = new PregelixJob(jobName);
+        job.setVertexClass(MessageOverflowVertex.class);
+        job.setVertexInputFormatClass(TextPageRankInputFormat.class);
+        job.setVertexOutputFormatClass(SimpleMessageOverflowVertexOutputFormat.class);
+        job.setNoramlizedKeyComputerClass(VLongNormalizedKeyComputer.class);
+        job.setDynamicVertexValueSize(true);
+        job.setFrameSize(2048);
+        FileInputFormat.setInputPaths(job, HDFS_INPUTPATH);
+        FileOutputFormat.setOutputPath(job, new Path(HDFS_OUTPUTPAH));
+        job.getConfiguration().setLong(PregelixJob.NUM_VERTICE, 20);
+        job.getConfiguration().writeXml(new FileOutputStream(new File(outputPath)));
+    }
+
+    private static void generateMessageOverflowJobLSM(String jobName, String outputPath) throws IOException {
+        PregelixJob job = new PregelixJob(jobName);
+        job.setVertexClass(MessageOverflowVertex.class);
+        job.setVertexInputFormatClass(TextPageRankInputFormat.class);
+        job.setVertexOutputFormatClass(SimpleMessageOverflowVertexOutputFormat.class);
+        job.setNoramlizedKeyComputerClass(VLongNormalizedKeyComputer.class);
+        job.setDynamicVertexValueSize(true);
+        job.setFrameSize(2048);
+        job.setLSMStorage(true);
+        FileInputFormat.setInputPaths(job, HDFS_INPUTPATH);
+        FileOutputFormat.setOutputPath(job, new Path(HDFS_OUTPUTPAH));
+        job.getConfiguration().setLong(PregelixJob.NUM_VERTICE, 20);
+        job.getConfiguration().writeXml(new FileOutputStream(new File(outputPath)));
+    }
+
+    private static void generateEarlyTerminationJob(String jobName, String outputPath) throws IOException {
+        PregelixJob job = new PregelixJob(jobName);
+        job.setVertexClass(EarlyTerminationVertex.class);
+        job.setVertexInputFormatClass(TextPageRankInputFormat.class);
+        job.setVertexOutputFormatClass(SimpleEarlyTerminattionVertexOutputFormat.class);
+        job.setNoramlizedKeyComputerClass(VLongNormalizedKeyComputer.class);
+        FileInputFormat.setInputPaths(job, HDFS_INPUTPATH);
+        FileOutputFormat.setOutputPath(job, new Path(HDFS_OUTPUTPAH));
+        job.getConfiguration().setLong(PregelixJob.NUM_VERTICE, 20);
+        job.getConfiguration().writeXml(new FileOutputStream(new File(outputPath)));
+    }
+
     private static void genPageRank() throws IOException {
         generatePageRankJob("PageRank", outputBase + "PageRank.xml");
         generatePageRankJobReal("PageRank", outputBase + "PageRankReal.xml");
@@ -319,6 +383,16 @@
         generateGraphMutationJob("Graph Mutation", outputBase + "GraphMutation.xml");
     }
 
+    private static void genMessageOverflow() throws IOException {
+        generateMessageOverflowJob("Message Overflow", outputBase + "MessageOverflow.xml");
+        generateMessageOverflowJobLSM("Message Overflow LSM", outputBase + "MessageOverflowLSM.xml");
+        generateMessageOverflowFixedsizeJob("Message Overflow Fixedsize", outputBase + "MessageOverflowFixedsize.xml");
+    }
+
+    private static void genEarlyTermination() throws IOException {
+        generateEarlyTerminationJob("Early Termination", outputBase + "EarlyTermination.xml");
+    }
+
     public static void main(String[] args) throws IOException {
         genPageRank();
         genShortestPath();
@@ -327,5 +401,7 @@
         genTriangleCounting();
         genMaximalClique();
         genGraphMutation();
+        genMessageOverflow();
+        genEarlyTermination();
     }
 }
diff --git a/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/lib/io/SizeEstimationTest.java b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/lib/io/SizeEstimationTest.java
new file mode 100644
index 0000000..638011b
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/lib/io/SizeEstimationTest.java
@@ -0,0 +1,176 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.example.lib.io;
+
+import java.io.ByteArrayOutputStream;
+import java.io.DataOutput;
+import java.io.DataOutputStream;
+import java.util.Random;
+
+import org.junit.Test;
+
+import edu.uci.ics.pregelix.api.graph.MsgList;
+import edu.uci.ics.pregelix.api.io.WritableSizable;
+import edu.uci.ics.pregelix.example.io.BooleanWritable;
+import edu.uci.ics.pregelix.example.io.ByteWritable;
+import edu.uci.ics.pregelix.example.io.DoubleWritable;
+import edu.uci.ics.pregelix.example.io.IntWritable;
+import edu.uci.ics.pregelix.example.io.LongWritable;
+import edu.uci.ics.pregelix.example.io.NullWritable;
+import edu.uci.ics.pregelix.example.io.VIntWritable;
+import edu.uci.ics.pregelix.example.io.VLongWritable;
+
+/**
+ * @author yingyib
+ */
+public class SizeEstimationTest {
+
+    @Test
+    public void testVLong() throws Exception {
+        Random rand = new Random(System.currentTimeMillis());
+        MsgList<WritableSizable> msgList = new MsgList<WritableSizable>();
+        msgList.add(new VLongWritable(Long.MAX_VALUE));
+        msgList.add(new VLongWritable(Long.MIN_VALUE));
+        msgList.add(new VLongWritable(-1));
+        for (int i = 0; i < 1000000; i++) {
+            msgList.add(new VLongWritable(Math.abs(rand.nextLong())));
+        }
+        verifyExactSizeEstimation(msgList);
+    }
+
+    @Test
+    public void testLong() throws Exception {
+        Random rand = new Random(System.currentTimeMillis());
+        MsgList<WritableSizable> msgList = new MsgList<WritableSizable>();
+        for (int i = 0; i < 1000000; i++) {
+            msgList.add(new LongWritable(rand.nextLong()));
+        }
+        verifySizeEstimation(msgList);
+    }
+
+    @Test
+    public void testBoolean() throws Exception {
+        Random rand = new Random(System.currentTimeMillis());
+        MsgList<WritableSizable> msgList = new MsgList<WritableSizable>();
+        for (int i = 0; i < 1000000; i++) {
+            msgList.add(new BooleanWritable(rand.nextBoolean()));
+        }
+        verifySizeEstimation(msgList);
+    }
+
+    @Test
+    public void testByte() throws Exception {
+        Random rand = new Random(System.currentTimeMillis());
+        MsgList<WritableSizable> msgList = new MsgList<WritableSizable>();
+        for (int i = 0; i < 1000000; i++) {
+            msgList.add(new ByteWritable((byte) rand.nextInt()));
+        }
+        verifySizeEstimation(msgList);
+    }
+
+    @Test
+    public void testDouble() throws Exception {
+        Random rand = new Random(System.currentTimeMillis());
+        MsgList<WritableSizable> msgList = new MsgList<WritableSizable>();
+        for (int i = 0; i < 1000000; i++) {
+            msgList.add(new DoubleWritable(rand.nextDouble()));
+        }
+        verifySizeEstimation(msgList);
+    }
+
+    @Test
+    public void testFloat() throws Exception {
+        Random rand = new Random(System.currentTimeMillis());
+        MsgList<WritableSizable> msgList = new MsgList<WritableSizable>();
+        for (int i = 0; i < 1000000; i++) {
+            msgList.add(new DoubleWritable(rand.nextFloat()));
+        }
+        verifySizeEstimation(msgList);
+    }
+
+    @Test
+    public void testNull() throws Exception {
+        MsgList<WritableSizable> msgList = new MsgList<WritableSizable>();
+        for (int i = 0; i < 1000000; i++) {
+            msgList.add(NullWritable.get());
+        }
+        verifySizeEstimation(msgList);
+    }
+
+    @Test
+    public void testVInt() throws Exception {
+        Random rand = new Random(System.currentTimeMillis());
+        MsgList<WritableSizable> msgList = new MsgList<WritableSizable>();
+        for (int i = 0; i < 1000000; i++) {
+            msgList.add(new VIntWritable(rand.nextInt()));
+        }
+        verifySizeEstimation(msgList);
+    }
+
+    @Test
+    public void testInt() throws Exception {
+        Random rand = new Random(System.currentTimeMillis());
+        MsgList<WritableSizable> msgList = new MsgList<WritableSizable>();
+        for (int i = 0; i < 1000000; i++) {
+            msgList.add(new IntWritable(rand.nextInt()));
+        }
+        verifySizeEstimation(msgList);
+    }
+
+    private void verifySizeEstimation(MsgList<WritableSizable> msgList) throws Exception {
+        ByteArrayOutputStream bos = new ByteArrayOutputStream();
+        DataOutput dos = new DataOutputStream(bos);
+        int accumulatedSize = 5;
+        for (int i = 0; i < msgList.size(); i++) {
+            bos.reset();
+            WritableSizable value = msgList.get(i);
+            value.write(dos);
+            if (value.sizeInBytes() < bos.size()) {
+                throw new Exception(value + " estimated size (" + value.sizeInBytes()
+                        + ") is smaller than the actual size" + bos.size());
+            }
+            accumulatedSize += value.sizeInBytes();
+        }
+        bos.reset();
+        msgList.write(dos);
+        if (accumulatedSize < bos.size()) {
+            throw new Exception("Estimated list size (" + accumulatedSize + ") is smaller than the actual size"
+                    + bos.size());
+        }
+    }
+
+    private void verifyExactSizeEstimation(MsgList<WritableSizable> msgList) throws Exception {
+        ByteArrayOutputStream bos = new ByteArrayOutputStream();
+        DataOutput dos = new DataOutputStream(bos);
+        int accumulatedSize = 5;
+        for (int i = 0; i < msgList.size(); i++) {
+            bos.reset();
+            WritableSizable value = msgList.get(i);
+            value.write(dos);
+            if (value.sizeInBytes() != bos.size()) {
+                throw new Exception(value + " estimated size (" + value.sizeInBytes()
+                        + ") is smaller than the actual size" + bos.size());
+            }
+            accumulatedSize += value.sizeInBytes();
+        }
+        bos.reset();
+        msgList.write(dos);
+        if (accumulatedSize < bos.size()) {
+            throw new Exception("Estimated list size (" + accumulatedSize + ") is smaller than the actual size"
+                    + bos.size());
+        }
+    }
+
+}
diff --git a/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/util/TestCluster.java b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/util/TestCluster.java
new file mode 100644
index 0000000..660d9eb
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/util/TestCluster.java
@@ -0,0 +1,150 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.example.util;
+
+import java.io.BufferedReader;
+import java.io.DataOutputStream;
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.logging.Logger;
+
+import org.apache.commons.io.FileUtils;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hdfs.MiniDFSCluster;
+import org.apache.hadoop.mapred.JobConf;
+
+import edu.uci.ics.pregelix.core.jobgen.clusterconfig.ClusterConfig;
+import edu.uci.ics.pregelix.core.util.PregelixHyracksIntegrationUtil;
+
+@SuppressWarnings("deprecation")
+public class TestCluster {
+    private static final Logger LOGGER = Logger.getLogger(TestCluster.class.getName());
+
+    private static final String ACTUAL_RESULT_DIR = "actual";
+    private static final String PATH_TO_HADOOP_CONF = "src/test/resources/hadoop/conf";
+    private static final String PATH_TO_CLUSTER_STORE = "src/test/resources/cluster/stores.properties";
+    private static final String PATH_TO_CLUSTER_PROPERTIES = "src/test/resources/cluster/cluster.properties";
+
+    private static final String DATA_PATH = "data/webmap/webmap_link.txt";
+    private static final String HDFS_PATH = "/webmap/";
+
+    private static final String DATA_PATH2 = "data/webmapcomplex/webmap_link.txt";
+    private static final String HDFS_PATH2 = "/webmapcomplex/";
+
+    private static final String DATA_PATH3 = "data/clique/clique.txt";
+    private static final String HDFS_PATH3 = "/clique/";
+
+    private static final String DATA_PATH4 = "data/clique2/clique.txt";
+    private static final String HDFS_PATH4 = "/clique2/";
+
+    private static final String DATA_PATH5 = "data/clique3/clique.txt";
+    private static final String HDFS_PATH5 = "/clique3/";
+
+    private static final String HADOOP_CONF_PATH = ACTUAL_RESULT_DIR + File.separator + "conf.xml";
+    private MiniDFSCluster dfsCluster;
+
+    private JobConf conf = new JobConf();
+    private int numberOfNC = 2;
+
+    public void setUp() throws Exception {
+        ClusterConfig.setStorePath(PATH_TO_CLUSTER_STORE);
+        ClusterConfig.setClusterPropertiesPath(PATH_TO_CLUSTER_PROPERTIES);
+        cleanupStores();
+        PregelixHyracksIntegrationUtil.init();
+        LOGGER.info("Hyracks mini-cluster started");
+        FileUtils.forceMkdir(new File(ACTUAL_RESULT_DIR));
+        FileUtils.cleanDirectory(new File(ACTUAL_RESULT_DIR));
+        startHDFS();
+    }
+
+    private void cleanupStores() throws IOException {
+        FileUtils.forceMkdir(new File("teststore"));
+        FileUtils.forceMkdir(new File("build"));
+        FileUtils.cleanDirectory(new File("teststore"));
+        FileUtils.cleanDirectory(new File("build"));
+    }
+
+    private void startHDFS() throws IOException {
+        conf.addResource(new Path(PATH_TO_HADOOP_CONF + "/core-site.xml"));
+        conf.addResource(new Path(PATH_TO_HADOOP_CONF + "/mapred-site.xml"));
+        conf.addResource(new Path(PATH_TO_HADOOP_CONF + "/hdfs-site.xml"));
+        FileSystem lfs = FileSystem.getLocal(new Configuration());
+        lfs.delete(new Path("build"), true);
+        System.setProperty("hadoop.log.dir", "logs");
+        dfsCluster = new MiniDFSCluster(conf, numberOfNC, true, null);
+        FileSystem dfs = FileSystem.get(conf);
+        Path src = new Path(DATA_PATH);
+        Path dest = new Path(HDFS_PATH);
+        dfs.mkdirs(dest);
+        dfs.copyFromLocalFile(src, dest);
+
+        src = new Path(DATA_PATH2);
+        dest = new Path(HDFS_PATH2);
+        dfs.mkdirs(dest);
+        dfs.copyFromLocalFile(src, dest);
+
+        src = new Path(DATA_PATH3);
+        dest = new Path(HDFS_PATH3);
+        dfs.mkdirs(dest);
+        dfs.copyFromLocalFile(src, dest);
+
+        src = new Path(DATA_PATH4);
+        dest = new Path(HDFS_PATH4);
+        dfs.mkdirs(dest);
+        dfs.copyFromLocalFile(src, dest);
+
+        src = new Path(DATA_PATH5);
+        dest = new Path(HDFS_PATH5);
+        dfs.mkdirs(dest);
+        dfs.copyFromLocalFile(src, dest);
+
+        DataOutputStream confOutput = new DataOutputStream(new FileOutputStream(new File(HADOOP_CONF_PATH)));
+        conf.writeXml(confOutput);
+        confOutput.flush();
+        confOutput.close();
+    }
+
+    /**
+     * cleanup hdfs cluster
+     */
+    public void cleanupHDFS() throws Exception {
+        dfsCluster.shutdown();
+    }
+
+    public void tearDown() throws Exception {
+        PregelixHyracksIntegrationUtil.deinit();
+        LOGGER.info("Hyracks mini-cluster shut down");
+        cleanupHDFS();
+    }
+
+    protected static List<String> getFileList(String ignorePath) throws FileNotFoundException, IOException {
+        BufferedReader reader = new BufferedReader(new FileReader(ignorePath));
+        String s = null;
+        List<String> ignores = new ArrayList<String>();
+        while ((s = reader.readLine()) != null) {
+            ignores.add(s);
+        }
+        reader.close();
+        return ignores;
+    }
+
+}
diff --git a/pregelix/pregelix-example/src/test/resources/expected/ConnectedComponentsRealComplex2/part-0 b/pregelix/pregelix-example/src/test/resources/expected/ConnectedComponentsRealComplex2/part-0
new file mode 100755
index 0000000..2c975de
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/expected/ConnectedComponentsRealComplex2/part-0
@@ -0,0 +1,10 @@
+0	0
+2	0
+4	0
+6	0
+8	0
+10	0
+12	0
+14	0
+16	0
+18	0
diff --git a/pregelix/pregelix-example/src/test/resources/expected/ConnectedComponentsRealComplex2/part-1 b/pregelix/pregelix-example/src/test/resources/expected/ConnectedComponentsRealComplex2/part-1
new file mode 100755
index 0000000..6976bc1
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/expected/ConnectedComponentsRealComplex2/part-1
@@ -0,0 +1,13 @@
+1	0
+3	0
+5	0
+7	0
+9	0
+11	0
+13	0
+15	0
+17	0
+19	0
+21	21
+25	25
+27	27
diff --git a/pregelix/pregelix-example/src/test/resources/expected/EarlyTermination/part-0 b/pregelix/pregelix-example/src/test/resources/expected/EarlyTermination/part-0
new file mode 100644
index 0000000..60a55af
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/expected/EarlyTermination/part-0
@@ -0,0 +1,5 @@
+0	2
+4	2
+8	2
+12	2
+16	2
diff --git a/pregelix/pregelix-example/src/test/resources/expected/EarlyTermination/part-1 b/pregelix/pregelix-example/src/test/resources/expected/EarlyTermination/part-1
new file mode 100644
index 0000000..32ee93f
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/expected/EarlyTermination/part-1
@@ -0,0 +1,5 @@
+1	2
+5	2
+9	2
+13	2
+17	2
diff --git a/pregelix/pregelix-example/src/test/resources/expected/EarlyTermination/part-2 b/pregelix/pregelix-example/src/test/resources/expected/EarlyTermination/part-2
new file mode 100644
index 0000000..542ccae
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/expected/EarlyTermination/part-2
@@ -0,0 +1,5 @@
+2	0
+6	0
+10	0
+14	0
+18	0
diff --git a/pregelix/pregelix-example/src/test/resources/expected/EarlyTermination/part-3 b/pregelix/pregelix-example/src/test/resources/expected/EarlyTermination/part-3
new file mode 100644
index 0000000..ff0e5b8
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/expected/EarlyTermination/part-3
@@ -0,0 +1,5 @@
+3	1
+7	1
+11	1
+15	1
+19	1
diff --git a/pregelix/pregelix-example/src/test/resources/expected/MessageOverflow/part-0 b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflow/part-0
new file mode 100644
index 0000000..db5f679
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflow/part-0
@@ -0,0 +1,5 @@
+0	10000
+4	70000
+8	30000
+12	90000
+16	50000
diff --git a/pregelix/pregelix-example/src/test/resources/expected/MessageOverflow/part-1 b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflow/part-1
new file mode 100644
index 0000000..3dc4629
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflow/part-1
@@ -0,0 +1,5 @@
+1	100000
+5	60000
+9	20000
+13	80000
+17	40000
diff --git a/pregelix/pregelix-example/src/test/resources/expected/MessageOverflow/part-2 b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflow/part-2
new file mode 100644
index 0000000..bc95831
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflow/part-2
@@ -0,0 +1,5 @@
+2	90000
+6	50000
+10	10000
+14	70000
+18	30000
diff --git a/pregelix/pregelix-example/src/test/resources/expected/MessageOverflow/part-3 b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflow/part-3
new file mode 100644
index 0000000..b619cd7
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflow/part-3
@@ -0,0 +1,5 @@
+3	80000
+7	40000
+11	100000
+15	60000
+19	20000
diff --git a/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowFixedsize/part-0 b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowFixedsize/part-0
new file mode 100644
index 0000000..db5f679
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowFixedsize/part-0
@@ -0,0 +1,5 @@
+0	10000
+4	70000
+8	30000
+12	90000
+16	50000
diff --git a/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowFixedsize/part-1 b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowFixedsize/part-1
new file mode 100644
index 0000000..3dc4629
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowFixedsize/part-1
@@ -0,0 +1,5 @@
+1	100000
+5	60000
+9	20000
+13	80000
+17	40000
diff --git a/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowFixedsize/part-2 b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowFixedsize/part-2
new file mode 100644
index 0000000..bc95831
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowFixedsize/part-2
@@ -0,0 +1,5 @@
+2	90000
+6	50000
+10	10000
+14	70000
+18	30000
diff --git a/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowFixedsize/part-3 b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowFixedsize/part-3
new file mode 100644
index 0000000..b619cd7
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowFixedsize/part-3
@@ -0,0 +1,5 @@
+3	80000
+7	40000
+11	100000
+15	60000
+19	20000
diff --git a/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowLSM/part-0 b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowLSM/part-0
new file mode 100644
index 0000000..db5f679
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowLSM/part-0
@@ -0,0 +1,5 @@
+0	10000
+4	70000
+8	30000
+12	90000
+16	50000
diff --git a/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowLSM/part-1 b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowLSM/part-1
new file mode 100644
index 0000000..3dc4629
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowLSM/part-1
@@ -0,0 +1,5 @@
+1	100000
+5	60000
+9	20000
+13	80000
+17	40000
diff --git a/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowLSM/part-2 b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowLSM/part-2
new file mode 100644
index 0000000..bc95831
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowLSM/part-2
@@ -0,0 +1,5 @@
+2	90000
+6	50000
+10	10000
+14	70000
+18	30000
diff --git a/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowLSM/part-3 b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowLSM/part-3
new file mode 100644
index 0000000..b619cd7
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/expected/MessageOverflowLSM/part-3
@@ -0,0 +1,5 @@
+3	80000
+7	40000
+11	100000
+15	60000
+19	20000
diff --git a/pregelix/pregelix-example/src/test/resources/expected/PageRankReal2/part-0 b/pregelix/pregelix-example/src/test/resources/expected/PageRankReal2/part-0
new file mode 100755
index 0000000..d135b86
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/expected/PageRankReal2/part-0
@@ -0,0 +1,10 @@
+0	0.008290140026154316
+2	0.14646839195826472
+4	0.03976979906329426
+6	0.015736276824953852
+8	0.010628239626209894
+10	0.008290140026154316
+12	0.14646839195826472
+14	0.03976979906329426
+16	0.015736276824953852
+18	0.010628239626209894
diff --git a/pregelix/pregelix-example/src/test/resources/expected/PageRankReal2/part-1 b/pregelix/pregelix-example/src/test/resources/expected/PageRankReal2/part-1
new file mode 100755
index 0000000..d3badee
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/expected/PageRankReal2/part-1
@@ -0,0 +1,10 @@
+1	0.15351528192471647
+3	0.08125113985998214
+5	0.0225041581462058
+7	0.012542224114863661
+9	0.009294348455354817
+11	0.15351528192471647
+13	0.08125113985998214
+15	0.0225041581462058
+17	0.012542224114863661
+19	0.009294348455354817
diff --git a/pregelix/pregelix-example/src/test/resources/jobs/ConnectedComponentsReal.xml b/pregelix/pregelix-example/src/test/resources/jobs/ConnectedComponentsReal.xml
index decbde8..df72d9b 100644
--- a/pregelix/pregelix-example/src/test/resources/jobs/ConnectedComponentsReal.xml
+++ b/pregelix/pregelix-example/src/test/resources/jobs/ConnectedComponentsReal.xml
@@ -127,6 +127,7 @@
 <property><name>pregelix.vertexInputFormatClass</name><value>edu.uci.ics.pregelix.example.inputformat.TextConnectedComponentsInputFormat</value></property>
 <property><name>mapred.job.queue.name</name><value>default</value></property>
 <property><name>mapred.job.tracker.persist.jobstatus.active</name><value>false</value></property>
+<property><name>pregelix.incStateLength</name><value>true</value></property>
 <property><name>mapred.reduce.slowstart.completed.maps</name><value>0.05</value></property>
 <property><name>topology.script.number.args</name><value>100</value></property>
 <property><name>mapred.skip.map.max.skip.records</name><value>0</value></property>
diff --git a/pregelix/pregelix-example/src/test/resources/jobs/ConnectedComponentsRealComplex.xml b/pregelix/pregelix-example/src/test/resources/jobs/ConnectedComponentsRealComplex.xml
index cca66bb..b0bf024 100644
--- a/pregelix/pregelix-example/src/test/resources/jobs/ConnectedComponentsRealComplex.xml
+++ b/pregelix/pregelix-example/src/test/resources/jobs/ConnectedComponentsRealComplex.xml
@@ -128,6 +128,7 @@
 <property><name>pregelix.vertexInputFormatClass</name><value>edu.uci.ics.pregelix.example.inputformat.TextConnectedComponentsInputFormat</value></property>
 <property><name>mapred.job.queue.name</name><value>default</value></property>
 <property><name>mapred.job.tracker.persist.jobstatus.active</name><value>false</value></property>
+<property><name>pregelix.incStateLength</name><value>true</value></property>
 <property><name>mapred.reduce.slowstart.completed.maps</name><value>0.05</value></property>
 <property><name>topology.script.number.args</name><value>100</value></property>
 <property><name>mapred.skip.map.max.skip.records</name><value>0</value></property>
diff --git a/pregelix/pregelix-example/src/test/resources/jobs/EarlyTermination.xml b/pregelix/pregelix-example/src/test/resources/jobs/EarlyTermination.xml
new file mode 100644
index 0000000..d908da8
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/jobs/EarlyTermination.xml
@@ -0,0 +1,142 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?><configuration>
+<property><name>mapred.tasktracker.dns.nameserver</name><value>default</value></property>
+<property><name>mapred.queue.default.acl-administer-jobs</name><value>*</value></property>
+<property><name>mapred.skip.map.auto.incr.proc.count</name><value>true</value></property>
+<property><name>mapred.jobtracker.instrumentation</name><value>org.apache.hadoop.mapred.JobTrackerMetricsInst</value></property>
+<property><name>mapred.skip.reduce.auto.incr.proc.count</name><value>true</value></property>
+<property><name>fs.hsftp.impl</name><value>org.apache.hadoop.hdfs.HsftpFileSystem</value></property>
+<property><name>mapred.input.dir</name><value>file:/webmap</value></property>
+<property><name>mapred.submit.replication</name><value>10</value></property>
+<property><name>ipc.server.tcpnodelay</name><value>false</value></property>
+<property><name>fs.checkpoint.dir</name><value>${hadoop.tmp.dir}/dfs/namesecondary</value></property>
+<property><name>mapred.output.compression.type</name><value>RECORD</value></property>
+<property><name>mapred.job.shuffle.merge.percent</name><value>0.66</value></property>
+<property><name>mapred.child.java.opts</name><value>-Xmx200m</value></property>
+<property><name>mapred.queue.default.acl-submit-job</name><value>*</value></property>
+<property><name>keep.failed.task.files</name><value>false</value></property>
+<property><name>mapred.jobtracker.job.history.block.size</name><value>3145728</value></property>
+<property><name>io.bytes.per.checksum</name><value>512</value></property>
+<property><name>mapred.task.tracker.report.address</name><value>127.0.0.1:0</value></property>
+<property><name>hadoop.util.hash.type</name><value>murmur</value></property>
+<property><name>fs.hdfs.impl</name><value>org.apache.hadoop.hdfs.DistributedFileSystem</value></property>
+<property><name>fs.ramfs.impl</name><value>org.apache.hadoop.fs.InMemoryFileSystem</value></property>
+<property><name>mapred.jobtracker.restart.recover</name><value>false</value></property>
+<property><name>fs.hftp.impl</name><value>org.apache.hadoop.hdfs.HftpFileSystem</value></property>
+<property><name>fs.checkpoint.period</name><value>3600</value></property>
+<property><name>mapred.child.tmp</name><value>./tmp</value></property>
+<property><name>mapred.local.dir.minspacekill</name><value>0</value></property>
+<property><name>map.sort.class</name><value>org.apache.hadoop.util.QuickSort</value></property>
+<property><name>hadoop.logfile.count</name><value>10</value></property>
+<property><name>ipc.client.connection.maxidletime</name><value>10000</value></property>
+<property><name>mapred.output.dir</name><value>/result</value></property>
+<property><name>io.map.index.skip</name><value>0</value></property>
+<property><name>mapred.tasktracker.expiry.interval</name><value>600000</value></property>
+<property><name>mapred.output.compress</name><value>false</value></property>
+<property><name>io.seqfile.lazydecompress</name><value>true</value></property>
+<property><name>mapred.reduce.parallel.copies</name><value>5</value></property>
+<property><name>fs.checkpoint.size</name><value>67108864</value></property>
+<property><name>mapred.job.reduce.input.buffer.percent</name><value>0.0</value></property>
+<property><name>mapred.job.name</name><value>Early Termination</value></property>
+<property><name>pregelix.nmkComputerClass</name><value>edu.uci.ics.pregelix.example.data.VLongNormalizedKeyComputer</value></property>
+<property><name>local.cache.size</name><value>10737418240</value></property>
+<property><name>fs.s3n.impl</name><value>org.apache.hadoop.fs.s3native.NativeS3FileSystem</value></property>
+<property><name>mapred.userlog.limit.kb</name><value>0</value></property>
+<property><name>fs.file.impl</name><value>org.apache.hadoop.fs.LocalFileSystem</value></property>
+<property><name>mapred.task.tracker.http.address</name><value>0.0.0.0:50060</value></property>
+<property><name>mapred.task.timeout</name><value>600000</value></property>
+<property><name>fs.kfs.impl</name><value>org.apache.hadoop.fs.kfs.KosmosFileSystem</value></property>
+<property><name>mapred.max.tracker.blacklists</name><value>4</value></property>
+<property><name>fs.s3.buffer.dir</name><value>${hadoop.tmp.dir}/s3</value></property>
+<property><name>mapred.job.tracker.persist.jobstatus.dir</name><value>/jobtracker/jobsInfo</value></property>
+<property><name>ipc.client.kill.max</name><value>10</value></property>
+<property><name>mapred.tasktracker.instrumentation</name><value>org.apache.hadoop.mapred.TaskTrackerMetricsInst</value></property>
+<property><name>mapred.reduce.tasks.speculative.execution</name><value>true</value></property>
+<property><name>io.sort.record.percent</name><value>0.05</value></property>
+<property><name>hadoop.security.authorization</name><value>false</value></property>
+<property><name>mapred.max.tracker.failures</name><value>4</value></property>
+<property><name>mapred.jobtracker.taskScheduler</name><value>org.apache.hadoop.mapred.JobQueueTaskScheduler</value></property>
+<property><name>pregelix.numVertices</name><value>20</value></property>
+<property><name>mapred.tasktracker.dns.interface</name><value>default</value></property>
+<property><name>mapred.map.tasks</name><value>2</value></property>
+<property><name>mapred.job.tracker.persist.jobstatus.hours</name><value>0</value></property>
+<property><name>fs.s3.sleepTimeSeconds</name><value>10</value></property>
+<property><name>fs.default.name</name><value>file:///</value></property>
+<property><name>tasktracker.http.threads</name><value>40</value></property>
+<property><name>mapred.tasktracker.taskmemorymanager.monitoring-interval</name><value>5000</value></property>
+<property><name>hadoop.rpc.socket.factory.class.default</name><value>org.apache.hadoop.net.StandardSocketFactory</value></property>
+<property><name>mapred.reduce.tasks</name><value>1</value></property>
+<property><name>topology.node.switch.mapping.impl</name><value>org.apache.hadoop.net.ScriptBasedMapping</value></property>
+<property><name>pregelix.vertexClass</name><value>edu.uci.ics.pregelix.example.EarlyTerminationVertex</value></property>
+<property><name>mapred.skip.reduce.max.skip.groups</name><value>0</value></property>
+<property><name>io.file.buffer.size</name><value>4096</value></property>
+<property><name>mapred.jobtracker.maxtasks.per.job</name><value>-1</value></property>
+<property><name>mapred.tasktracker.indexcache.mb</name><value>10</value></property>
+<property><name>mapred.tasktracker.map.tasks.maximum</name><value>2</value></property>
+<property><name>fs.har.impl.disable.cache</name><value>true</value></property>
+<property><name>mapred.task.profile.maps</name><value>0-2</value></property>
+<property><name>hadoop.native.lib</name><value>true</value></property>
+<property><name>fs.s3.block.size</name><value>67108864</value></property>
+<property><name>mapred.job.reuse.jvm.num.tasks</name><value>1</value></property>
+<property><name>mapred.job.tracker.http.address</name><value>0.0.0.0:50030</value></property>
+<property><name>mapred.tasktracker.reduce.tasks.maximum</name><value>2</value></property>
+<property><name>io.compression.codecs</name><value>org.apache.hadoop.io.compress.DefaultCodec,org.apache.hadoop.io.compress.GzipCodec,org.apache.hadoop.io.compress.BZip2Codec</value></property>
+<property><name>mapred.job.shuffle.input.buffer.percent</name><value>0.70</value></property>
+<property><name>io.seqfile.compress.blocksize</name><value>1000000</value></property>
+<property><name>mapred.queue.names</name><value>default</value></property>
+<property><name>fs.har.impl</name><value>org.apache.hadoop.fs.HarFileSystem</value></property>
+<property><name>io.mapfile.bloom.error.rate</name><value>0.005</value></property>
+<property><name>mapred.job.tracker</name><value>local</value></property>
+<property><name>io.skip.checksum.errors</name><value>false</value></property>
+<property><name>mapred.reduce.max.attempts</name><value>4</value></property>
+<property><name>fs.s3.maxRetries</name><value>4</value></property>
+<property><name>ipc.server.listen.queue.size</name><value>128</value></property>
+<property><name>fs.trash.interval</name><value>0</value></property>
+<property><name>mapred.local.dir.minspacestart</name><value>0</value></property>
+<property><name>fs.s3.impl</name><value>org.apache.hadoop.fs.s3.S3FileSystem</value></property>
+<property><name>io.seqfile.sorter.recordlimit</name><value>1000000</value></property>
+<property><name>io.mapfile.bloom.size</name><value>1048576</value></property>
+<property><name>io.sort.mb</name><value>100</value></property>
+<property><name>mapred.local.dir</name><value>${hadoop.tmp.dir}/mapred/local</value></property>
+<property><name>io.sort.factor</name><value>10</value></property>
+<property><name>mapred.task.profile</name><value>false</value></property>
+<property><name>job.end.retry.interval</name><value>30000</value></property>
+<property><name>mapred.tasktracker.procfsbasedprocesstree.sleeptime-before-sigkill</name><value>5000</value></property>
+<property><name>mapred.jobtracker.completeuserjobs.maximum</name><value>100</value></property>
+<property><name>mapred.task.profile.reduces</name><value>0-2</value></property>
+<property><name>webinterface.private.actions</name><value>false</value></property>
+<property><name>hadoop.tmp.dir</name><value>/tmp/hadoop-${user.name}</value></property>
+<property><name>mapred.output.compression.codec</name><value>org.apache.hadoop.io.compress.DefaultCodec</value></property>
+<property><name>mapred.skip.attempts.to.start.skipping</name><value>2</value></property>
+<property><name>mapred.temp.dir</name><value>${hadoop.tmp.dir}/mapred/temp</value></property>
+<property><name>mapred.merge.recordsBeforeProgress</name><value>10000</value></property>
+<property><name>mapred.map.output.compression.codec</name><value>org.apache.hadoop.io.compress.DefaultCodec</value></property>
+<property><name>mapred.compress.map.output</name><value>false</value></property>
+<property><name>io.sort.spill.percent</name><value>0.80</value></property>
+<property><name>fs.checkpoint.edits.dir</name><value>${fs.checkpoint.dir}</value></property>
+<property><name>mapred.userlog.retain.hours</name><value>24</value></property>
+<property><name>mapred.system.dir</name><value>${hadoop.tmp.dir}/mapred/system</value></property>
+<property><name>mapred.line.input.format.linespermap</name><value>1</value></property>
+<property><name>job.end.retry.attempts</name><value>0</value></property>
+<property><name>ipc.client.idlethreshold</name><value>4000</value></property>
+<property><name>pregelix.vertexOutputFormatClass</name><value>edu.uci.ics.pregelix.example.EarlyTerminationVertex$SimpleEarlyTerminattionVertexOutputFormat</value></property>
+<property><name>mapred.reduce.copy.backoff</name><value>300</value></property>
+<property><name>mapred.map.tasks.speculative.execution</name><value>true</value></property>
+<property><name>mapred.inmem.merge.threshold</name><value>1000</value></property>
+<property><name>hadoop.logfile.size</name><value>10000000</value></property>
+<property><name>pregelix.vertexInputFormatClass</name><value>edu.uci.ics.pregelix.example.inputformat.TextPageRankInputFormat</value></property>
+<property><name>mapred.job.queue.name</name><value>default</value></property>
+<property><name>mapred.job.tracker.persist.jobstatus.active</name><value>false</value></property>
+<property><name>mapred.reduce.slowstart.completed.maps</name><value>0.05</value></property>
+<property><name>topology.script.number.args</name><value>100</value></property>
+<property><name>mapred.skip.map.max.skip.records</name><value>0</value></property>
+<property><name>fs.ftp.impl</name><value>org.apache.hadoop.fs.ftp.FTPFileSystem</value></property>
+<property><name>mapred.task.cache.levels</name><value>2</value></property>
+<property><name>mapred.job.tracker.handler.count</name><value>10</value></property>
+<property><name>io.serializations</name><value>org.apache.hadoop.io.serializer.WritableSerialization</value></property>
+<property><name>ipc.client.connect.max.retries</name><value>10</value></property>
+<property><name>mapred.min.split.size</name><value>0</value></property>
+<property><name>mapred.map.max.attempts</name><value>4</value></property>
+<property><name>jobclient.output.filter</name><value>FAILED</value></property>
+<property><name>ipc.client.tcpnodelay</name><value>false</value></property>
+<property><name>mapred.acls.enabled</name><value>false</value></property>
+</configuration>
\ No newline at end of file
diff --git a/pregelix/pregelix-example/src/test/resources/jobs/MessageOverflow.xml b/pregelix/pregelix-example/src/test/resources/jobs/MessageOverflow.xml
new file mode 100644
index 0000000..8316c64
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/jobs/MessageOverflow.xml
@@ -0,0 +1,144 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?><configuration>
+<property><name>mapred.tasktracker.dns.nameserver</name><value>default</value></property>
+<property><name>mapred.queue.default.acl-administer-jobs</name><value>*</value></property>
+<property><name>mapred.skip.map.auto.incr.proc.count</name><value>true</value></property>
+<property><name>mapred.jobtracker.instrumentation</name><value>org.apache.hadoop.mapred.JobTrackerMetricsInst</value></property>
+<property><name>mapred.skip.reduce.auto.incr.proc.count</name><value>true</value></property>
+<property><name>fs.hsftp.impl</name><value>org.apache.hadoop.hdfs.HsftpFileSystem</value></property>
+<property><name>mapred.input.dir</name><value>file:/webmap</value></property>
+<property><name>mapred.submit.replication</name><value>10</value></property>
+<property><name>ipc.server.tcpnodelay</name><value>false</value></property>
+<property><name>fs.checkpoint.dir</name><value>${hadoop.tmp.dir}/dfs/namesecondary</value></property>
+<property><name>mapred.output.compression.type</name><value>RECORD</value></property>
+<property><name>mapred.job.shuffle.merge.percent</name><value>0.66</value></property>
+<property><name>mapred.child.java.opts</name><value>-Xmx200m</value></property>
+<property><name>mapred.queue.default.acl-submit-job</name><value>*</value></property>
+<property><name>keep.failed.task.files</name><value>false</value></property>
+<property><name>mapred.jobtracker.job.history.block.size</name><value>3145728</value></property>
+<property><name>io.bytes.per.checksum</name><value>512</value></property>
+<property><name>mapred.task.tracker.report.address</name><value>127.0.0.1:0</value></property>
+<property><name>hadoop.util.hash.type</name><value>murmur</value></property>
+<property><name>fs.hdfs.impl</name><value>org.apache.hadoop.hdfs.DistributedFileSystem</value></property>
+<property><name>fs.ramfs.impl</name><value>org.apache.hadoop.fs.InMemoryFileSystem</value></property>
+<property><name>mapred.jobtracker.restart.recover</name><value>false</value></property>
+<property><name>fs.hftp.impl</name><value>org.apache.hadoop.hdfs.HftpFileSystem</value></property>
+<property><name>fs.checkpoint.period</name><value>3600</value></property>
+<property><name>mapred.child.tmp</name><value>./tmp</value></property>
+<property><name>mapred.local.dir.minspacekill</name><value>0</value></property>
+<property><name>map.sort.class</name><value>org.apache.hadoop.util.QuickSort</value></property>
+<property><name>hadoop.logfile.count</name><value>10</value></property>
+<property><name>ipc.client.connection.maxidletime</name><value>10000</value></property>
+<property><name>mapred.output.dir</name><value>/result</value></property>
+<property><name>io.map.index.skip</name><value>0</value></property>
+<property><name>mapred.tasktracker.expiry.interval</name><value>600000</value></property>
+<property><name>mapred.output.compress</name><value>false</value></property>
+<property><name>io.seqfile.lazydecompress</name><value>true</value></property>
+<property><name>mapred.reduce.parallel.copies</name><value>5</value></property>
+<property><name>fs.checkpoint.size</name><value>67108864</value></property>
+<property><name>mapred.job.reduce.input.buffer.percent</name><value>0.0</value></property>
+<property><name>mapred.job.name</name><value>Message Overflow</value></property>
+<property><name>pregelix.nmkComputerClass</name><value>edu.uci.ics.pregelix.example.data.VLongNormalizedKeyComputer</value></property>
+<property><name>local.cache.size</name><value>10737418240</value></property>
+<property><name>fs.s3n.impl</name><value>org.apache.hadoop.fs.s3native.NativeS3FileSystem</value></property>
+<property><name>mapred.userlog.limit.kb</name><value>0</value></property>
+<property><name>fs.file.impl</name><value>org.apache.hadoop.fs.LocalFileSystem</value></property>
+<property><name>mapred.task.tracker.http.address</name><value>0.0.0.0:50060</value></property>
+<property><name>mapred.task.timeout</name><value>600000</value></property>
+<property><name>fs.kfs.impl</name><value>org.apache.hadoop.fs.kfs.KosmosFileSystem</value></property>
+<property><name>mapred.max.tracker.blacklists</name><value>4</value></property>
+<property><name>fs.s3.buffer.dir</name><value>${hadoop.tmp.dir}/s3</value></property>
+<property><name>mapred.job.tracker.persist.jobstatus.dir</name><value>/jobtracker/jobsInfo</value></property>
+<property><name>ipc.client.kill.max</name><value>10</value></property>
+<property><name>mapred.tasktracker.instrumentation</name><value>org.apache.hadoop.mapred.TaskTrackerMetricsInst</value></property>
+<property><name>mapred.reduce.tasks.speculative.execution</name><value>true</value></property>
+<property><name>io.sort.record.percent</name><value>0.05</value></property>
+<property><name>hadoop.security.authorization</name><value>false</value></property>
+<property><name>mapred.max.tracker.failures</name><value>4</value></property>
+<property><name>mapred.jobtracker.taskScheduler</name><value>org.apache.hadoop.mapred.JobQueueTaskScheduler</value></property>
+<property><name>pregelix.numVertices</name><value>20</value></property>
+<property><name>mapred.tasktracker.dns.interface</name><value>default</value></property>
+<property><name>mapred.map.tasks</name><value>2</value></property>
+<property><name>mapred.job.tracker.persist.jobstatus.hours</name><value>0</value></property>
+<property><name>fs.s3.sleepTimeSeconds</name><value>10</value></property>
+<property><name>fs.default.name</name><value>file:///</value></property>
+<property><name>tasktracker.http.threads</name><value>40</value></property>
+<property><name>mapred.tasktracker.taskmemorymanager.monitoring-interval</name><value>5000</value></property>
+<property><name>hadoop.rpc.socket.factory.class.default</name><value>org.apache.hadoop.net.StandardSocketFactory</value></property>
+<property><name>mapred.reduce.tasks</name><value>1</value></property>
+<property><name>topology.node.switch.mapping.impl</name><value>org.apache.hadoop.net.ScriptBasedMapping</value></property>
+<property><name>pregelix.vertexClass</name><value>edu.uci.ics.pregelix.example.MessageOverflowVertex</value></property>
+<property><name>mapred.skip.reduce.max.skip.groups</name><value>0</value></property>
+<property><name>io.file.buffer.size</name><value>4096</value></property>
+<property><name>mapred.jobtracker.maxtasks.per.job</name><value>-1</value></property>
+<property><name>mapred.tasktracker.indexcache.mb</name><value>10</value></property>
+<property><name>mapred.tasktracker.map.tasks.maximum</name><value>2</value></property>
+<property><name>fs.har.impl.disable.cache</name><value>true</value></property>
+<property><name>mapred.task.profile.maps</name><value>0-2</value></property>
+<property><name>hadoop.native.lib</name><value>true</value></property>
+<property><name>fs.s3.block.size</name><value>67108864</value></property>
+<property><name>mapred.job.reuse.jvm.num.tasks</name><value>1</value></property>
+<property><name>mapred.job.tracker.http.address</name><value>0.0.0.0:50030</value></property>
+<property><name>mapred.tasktracker.reduce.tasks.maximum</name><value>2</value></property>
+<property><name>io.compression.codecs</name><value>org.apache.hadoop.io.compress.DefaultCodec,org.apache.hadoop.io.compress.GzipCodec,org.apache.hadoop.io.compress.BZip2Codec</value></property>
+<property><name>mapred.job.shuffle.input.buffer.percent</name><value>0.70</value></property>
+<property><name>io.seqfile.compress.blocksize</name><value>1000000</value></property>
+<property><name>mapred.queue.names</name><value>default</value></property>
+<property><name>fs.har.impl</name><value>org.apache.hadoop.fs.HarFileSystem</value></property>
+<property><name>io.mapfile.bloom.error.rate</name><value>0.005</value></property>
+<property><name>mapred.job.tracker</name><value>local</value></property>
+<property><name>io.skip.checksum.errors</name><value>false</value></property>
+<property><name>mapred.reduce.max.attempts</name><value>4</value></property>
+<property><name>fs.s3.maxRetries</name><value>4</value></property>
+<property><name>ipc.server.listen.queue.size</name><value>128</value></property>
+<property><name>fs.trash.interval</name><value>0</value></property>
+<property><name>mapred.local.dir.minspacestart</name><value>0</value></property>
+<property><name>fs.s3.impl</name><value>org.apache.hadoop.fs.s3.S3FileSystem</value></property>
+<property><name>io.seqfile.sorter.recordlimit</name><value>1000000</value></property>
+<property><name>io.mapfile.bloom.size</name><value>1048576</value></property>
+<property><name>io.sort.mb</name><value>100</value></property>
+<property><name>mapred.local.dir</name><value>${hadoop.tmp.dir}/mapred/local</value></property>
+<property><name>io.sort.factor</name><value>10</value></property>
+<property><name>mapred.task.profile</name><value>false</value></property>
+<property><name>job.end.retry.interval</name><value>30000</value></property>
+<property><name>mapred.tasktracker.procfsbasedprocesstree.sleeptime-before-sigkill</name><value>5000</value></property>
+<property><name>mapred.jobtracker.completeuserjobs.maximum</name><value>100</value></property>
+<property><name>mapred.task.profile.reduces</name><value>0-2</value></property>
+<property><name>webinterface.private.actions</name><value>false</value></property>
+<property><name>hadoop.tmp.dir</name><value>/tmp/hadoop-${user.name}</value></property>
+<property><name>pregelix.framesize</name><value>2048</value></property>
+<property><name>mapred.output.compression.codec</name><value>org.apache.hadoop.io.compress.DefaultCodec</value></property>
+<property><name>mapred.skip.attempts.to.start.skipping</name><value>2</value></property>
+<property><name>mapred.temp.dir</name><value>${hadoop.tmp.dir}/mapred/temp</value></property>
+<property><name>mapred.merge.recordsBeforeProgress</name><value>10000</value></property>
+<property><name>mapred.map.output.compression.codec</name><value>org.apache.hadoop.io.compress.DefaultCodec</value></property>
+<property><name>mapred.compress.map.output</name><value>false</value></property>
+<property><name>io.sort.spill.percent</name><value>0.80</value></property>
+<property><name>fs.checkpoint.edits.dir</name><value>${fs.checkpoint.dir}</value></property>
+<property><name>mapred.userlog.retain.hours</name><value>24</value></property>
+<property><name>mapred.system.dir</name><value>${hadoop.tmp.dir}/mapred/system</value></property>
+<property><name>mapred.line.input.format.linespermap</name><value>1</value></property>
+<property><name>job.end.retry.attempts</name><value>0</value></property>
+<property><name>ipc.client.idlethreshold</name><value>4000</value></property>
+<property><name>pregelix.vertexOutputFormatClass</name><value>edu.uci.ics.pregelix.example.MessageOverflowVertex$SimpleMessageOverflowVertexOutputFormat</value></property>
+<property><name>mapred.reduce.copy.backoff</name><value>300</value></property>
+<property><name>mapred.map.tasks.speculative.execution</name><value>true</value></property>
+<property><name>mapred.inmem.merge.threshold</name><value>1000</value></property>
+<property><name>hadoop.logfile.size</name><value>10000000</value></property>
+<property><name>pregelix.vertexInputFormatClass</name><value>edu.uci.ics.pregelix.example.inputformat.TextPageRankInputFormat</value></property>
+<property><name>mapred.job.queue.name</name><value>default</value></property>
+<property><name>mapred.job.tracker.persist.jobstatus.active</name><value>false</value></property>
+<property><name>pregelix.incStateLength</name><value>true</value></property>
+<property><name>mapred.reduce.slowstart.completed.maps</name><value>0.05</value></property>
+<property><name>topology.script.number.args</name><value>100</value></property>
+<property><name>mapred.skip.map.max.skip.records</name><value>0</value></property>
+<property><name>fs.ftp.impl</name><value>org.apache.hadoop.fs.ftp.FTPFileSystem</value></property>
+<property><name>mapred.task.cache.levels</name><value>2</value></property>
+<property><name>mapred.job.tracker.handler.count</name><value>10</value></property>
+<property><name>io.serializations</name><value>org.apache.hadoop.io.serializer.WritableSerialization</value></property>
+<property><name>ipc.client.connect.max.retries</name><value>10</value></property>
+<property><name>mapred.min.split.size</name><value>0</value></property>
+<property><name>mapred.map.max.attempts</name><value>4</value></property>
+<property><name>jobclient.output.filter</name><value>FAILED</value></property>
+<property><name>ipc.client.tcpnodelay</name><value>false</value></property>
+<property><name>mapred.acls.enabled</name><value>false</value></property>
+</configuration>
\ No newline at end of file
diff --git a/pregelix/pregelix-example/src/test/resources/jobs/MessageOverflowFixedsize.xml b/pregelix/pregelix-example/src/test/resources/jobs/MessageOverflowFixedsize.xml
new file mode 100644
index 0000000..a894ccd
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/jobs/MessageOverflowFixedsize.xml
@@ -0,0 +1,142 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?><configuration>
+<property><name>mapred.tasktracker.dns.nameserver</name><value>default</value></property>
+<property><name>mapred.queue.default.acl-administer-jobs</name><value>*</value></property>
+<property><name>mapred.skip.map.auto.incr.proc.count</name><value>true</value></property>
+<property><name>mapred.jobtracker.instrumentation</name><value>org.apache.hadoop.mapred.JobTrackerMetricsInst</value></property>
+<property><name>mapred.skip.reduce.auto.incr.proc.count</name><value>true</value></property>
+<property><name>fs.hsftp.impl</name><value>org.apache.hadoop.hdfs.HsftpFileSystem</value></property>
+<property><name>mapred.input.dir</name><value>file:/webmap</value></property>
+<property><name>mapred.submit.replication</name><value>10</value></property>
+<property><name>ipc.server.tcpnodelay</name><value>false</value></property>
+<property><name>fs.checkpoint.dir</name><value>${hadoop.tmp.dir}/dfs/namesecondary</value></property>
+<property><name>mapred.output.compression.type</name><value>RECORD</value></property>
+<property><name>mapred.job.shuffle.merge.percent</name><value>0.66</value></property>
+<property><name>mapred.child.java.opts</name><value>-Xmx200m</value></property>
+<property><name>mapred.queue.default.acl-submit-job</name><value>*</value></property>
+<property><name>keep.failed.task.files</name><value>false</value></property>
+<property><name>mapred.jobtracker.job.history.block.size</name><value>3145728</value></property>
+<property><name>io.bytes.per.checksum</name><value>512</value></property>
+<property><name>mapred.task.tracker.report.address</name><value>127.0.0.1:0</value></property>
+<property><name>hadoop.util.hash.type</name><value>murmur</value></property>
+<property><name>fs.hdfs.impl</name><value>org.apache.hadoop.hdfs.DistributedFileSystem</value></property>
+<property><name>fs.ramfs.impl</name><value>org.apache.hadoop.fs.InMemoryFileSystem</value></property>
+<property><name>mapred.jobtracker.restart.recover</name><value>false</value></property>
+<property><name>fs.hftp.impl</name><value>org.apache.hadoop.hdfs.HftpFileSystem</value></property>
+<property><name>fs.checkpoint.period</name><value>3600</value></property>
+<property><name>mapred.child.tmp</name><value>./tmp</value></property>
+<property><name>mapred.local.dir.minspacekill</name><value>0</value></property>
+<property><name>map.sort.class</name><value>org.apache.hadoop.util.QuickSort</value></property>
+<property><name>hadoop.logfile.count</name><value>10</value></property>
+<property><name>ipc.client.connection.maxidletime</name><value>10000</value></property>
+<property><name>mapred.output.dir</name><value>/result</value></property>
+<property><name>io.map.index.skip</name><value>0</value></property>
+<property><name>mapred.tasktracker.expiry.interval</name><value>600000</value></property>
+<property><name>mapred.output.compress</name><value>false</value></property>
+<property><name>io.seqfile.lazydecompress</name><value>true</value></property>
+<property><name>mapred.reduce.parallel.copies</name><value>5</value></property>
+<property><name>fs.checkpoint.size</name><value>67108864</value></property>
+<property><name>mapred.job.reduce.input.buffer.percent</name><value>0.0</value></property>
+<property><name>mapred.job.name</name><value>Message Overflow Fixedsize</value></property>
+<property><name>local.cache.size</name><value>10737418240</value></property>
+<property><name>fs.s3n.impl</name><value>org.apache.hadoop.fs.s3native.NativeS3FileSystem</value></property>
+<property><name>mapred.userlog.limit.kb</name><value>0</value></property>
+<property><name>fs.file.impl</name><value>org.apache.hadoop.fs.LocalFileSystem</value></property>
+<property><name>mapred.task.tracker.http.address</name><value>0.0.0.0:50060</value></property>
+<property><name>mapred.task.timeout</name><value>600000</value></property>
+<property><name>fs.kfs.impl</name><value>org.apache.hadoop.fs.kfs.KosmosFileSystem</value></property>
+<property><name>mapred.max.tracker.blacklists</name><value>4</value></property>
+<property><name>fs.s3.buffer.dir</name><value>${hadoop.tmp.dir}/s3</value></property>
+<property><name>mapred.job.tracker.persist.jobstatus.dir</name><value>/jobtracker/jobsInfo</value></property>
+<property><name>ipc.client.kill.max</name><value>10</value></property>
+<property><name>mapred.tasktracker.instrumentation</name><value>org.apache.hadoop.mapred.TaskTrackerMetricsInst</value></property>
+<property><name>mapred.reduce.tasks.speculative.execution</name><value>true</value></property>
+<property><name>io.sort.record.percent</name><value>0.05</value></property>
+<property><name>hadoop.security.authorization</name><value>false</value></property>
+<property><name>mapred.max.tracker.failures</name><value>4</value></property>
+<property><name>mapred.jobtracker.taskScheduler</name><value>org.apache.hadoop.mapred.JobQueueTaskScheduler</value></property>
+<property><name>pregelix.numVertices</name><value>20</value></property>
+<property><name>mapred.tasktracker.dns.interface</name><value>default</value></property>
+<property><name>mapred.map.tasks</name><value>2</value></property>
+<property><name>mapred.job.tracker.persist.jobstatus.hours</name><value>0</value></property>
+<property><name>fs.s3.sleepTimeSeconds</name><value>10</value></property>
+<property><name>fs.default.name</name><value>file:///</value></property>
+<property><name>tasktracker.http.threads</name><value>40</value></property>
+<property><name>mapred.tasktracker.taskmemorymanager.monitoring-interval</name><value>5000</value></property>
+<property><name>hadoop.rpc.socket.factory.class.default</name><value>org.apache.hadoop.net.StandardSocketFactory</value></property>
+<property><name>mapred.reduce.tasks</name><value>1</value></property>
+<property><name>topology.node.switch.mapping.impl</name><value>org.apache.hadoop.net.ScriptBasedMapping</value></property>
+<property><name>pregelix.vertexClass</name><value>edu.uci.ics.pregelix.example.MessageOverflowFixedsizeVertex</value></property>
+<property><name>mapred.skip.reduce.max.skip.groups</name><value>0</value></property>
+<property><name>io.file.buffer.size</name><value>4096</value></property>
+<property><name>mapred.jobtracker.maxtasks.per.job</name><value>-1</value></property>
+<property><name>mapred.tasktracker.indexcache.mb</name><value>10</value></property>
+<property><name>mapred.tasktracker.map.tasks.maximum</name><value>2</value></property>
+<property><name>fs.har.impl.disable.cache</name><value>true</value></property>
+<property><name>mapred.task.profile.maps</name><value>0-2</value></property>
+<property><name>hadoop.native.lib</name><value>true</value></property>
+<property><name>fs.s3.block.size</name><value>67108864</value></property>
+<property><name>mapred.job.reuse.jvm.num.tasks</name><value>1</value></property>
+<property><name>mapred.job.tracker.http.address</name><value>0.0.0.0:50030</value></property>
+<property><name>mapred.tasktracker.reduce.tasks.maximum</name><value>2</value></property>
+<property><name>io.compression.codecs</name><value>org.apache.hadoop.io.compress.DefaultCodec,org.apache.hadoop.io.compress.GzipCodec,org.apache.hadoop.io.compress.BZip2Codec</value></property>
+<property><name>mapred.job.shuffle.input.buffer.percent</name><value>0.70</value></property>
+<property><name>io.seqfile.compress.blocksize</name><value>1000000</value></property>
+<property><name>mapred.queue.names</name><value>default</value></property>
+<property><name>fs.har.impl</name><value>org.apache.hadoop.fs.HarFileSystem</value></property>
+<property><name>io.mapfile.bloom.error.rate</name><value>0.005</value></property>
+<property><name>mapred.job.tracker</name><value>local</value></property>
+<property><name>io.skip.checksum.errors</name><value>false</value></property>
+<property><name>mapred.reduce.max.attempts</name><value>4</value></property>
+<property><name>fs.s3.maxRetries</name><value>4</value></property>
+<property><name>ipc.server.listen.queue.size</name><value>128</value></property>
+<property><name>fs.trash.interval</name><value>0</value></property>
+<property><name>mapred.local.dir.minspacestart</name><value>0</value></property>
+<property><name>fs.s3.impl</name><value>org.apache.hadoop.fs.s3.S3FileSystem</value></property>
+<property><name>io.seqfile.sorter.recordlimit</name><value>1000000</value></property>
+<property><name>io.mapfile.bloom.size</name><value>1048576</value></property>
+<property><name>io.sort.mb</name><value>100</value></property>
+<property><name>mapred.local.dir</name><value>${hadoop.tmp.dir}/mapred/local</value></property>
+<property><name>io.sort.factor</name><value>10</value></property>
+<property><name>mapred.task.profile</name><value>false</value></property>
+<property><name>job.end.retry.interval</name><value>30000</value></property>
+<property><name>mapred.tasktracker.procfsbasedprocesstree.sleeptime-before-sigkill</name><value>5000</value></property>
+<property><name>mapred.jobtracker.completeuserjobs.maximum</name><value>100</value></property>
+<property><name>mapred.task.profile.reduces</name><value>0-2</value></property>
+<property><name>webinterface.private.actions</name><value>false</value></property>
+<property><name>hadoop.tmp.dir</name><value>/tmp/hadoop-${user.name}</value></property>
+<property><name>pregelix.framesize</name><value>2048</value></property>
+<property><name>mapred.output.compression.codec</name><value>org.apache.hadoop.io.compress.DefaultCodec</value></property>
+<property><name>mapred.skip.attempts.to.start.skipping</name><value>2</value></property>
+<property><name>mapred.temp.dir</name><value>${hadoop.tmp.dir}/mapred/temp</value></property>
+<property><name>mapred.merge.recordsBeforeProgress</name><value>10000</value></property>
+<property><name>mapred.map.output.compression.codec</name><value>org.apache.hadoop.io.compress.DefaultCodec</value></property>
+<property><name>mapred.compress.map.output</name><value>false</value></property>
+<property><name>io.sort.spill.percent</name><value>0.80</value></property>
+<property><name>fs.checkpoint.edits.dir</name><value>${fs.checkpoint.dir}</value></property>
+<property><name>mapred.userlog.retain.hours</name><value>24</value></property>
+<property><name>mapred.system.dir</name><value>${hadoop.tmp.dir}/mapred/system</value></property>
+<property><name>mapred.line.input.format.linespermap</name><value>1</value></property>
+<property><name>job.end.retry.attempts</name><value>0</value></property>
+<property><name>ipc.client.idlethreshold</name><value>4000</value></property>
+<property><name>pregelix.vertexOutputFormatClass</name><value>edu.uci.ics.pregelix.example.MessageOverflowFixedsizeVertex$SimpleMessageOverflowVertexOutputFormat</value></property>
+<property><name>mapred.reduce.copy.backoff</name><value>300</value></property>
+<property><name>mapred.map.tasks.speculative.execution</name><value>true</value></property>
+<property><name>mapred.inmem.merge.threshold</name><value>1000</value></property>
+<property><name>hadoop.logfile.size</name><value>10000000</value></property>
+<property><name>pregelix.vertexInputFormatClass</name><value>edu.uci.ics.pregelix.example.inputformat.TextPageRankInputFormat</value></property>
+<property><name>mapred.job.queue.name</name><value>default</value></property>
+<property><name>mapred.job.tracker.persist.jobstatus.active</name><value>false</value></property>
+<property><name>mapred.reduce.slowstart.completed.maps</name><value>0.05</value></property>
+<property><name>topology.script.number.args</name><value>100</value></property>
+<property><name>mapred.skip.map.max.skip.records</name><value>0</value></property>
+<property><name>fs.ftp.impl</name><value>org.apache.hadoop.fs.ftp.FTPFileSystem</value></property>
+<property><name>mapred.task.cache.levels</name><value>2</value></property>
+<property><name>mapred.job.tracker.handler.count</name><value>10</value></property>
+<property><name>io.serializations</name><value>org.apache.hadoop.io.serializer.WritableSerialization</value></property>
+<property><name>ipc.client.connect.max.retries</name><value>10</value></property>
+<property><name>mapred.min.split.size</name><value>0</value></property>
+<property><name>mapred.map.max.attempts</name><value>4</value></property>
+<property><name>jobclient.output.filter</name><value>FAILED</value></property>
+<property><name>ipc.client.tcpnodelay</name><value>false</value></property>
+<property><name>mapred.acls.enabled</name><value>false</value></property>
+</configuration>
\ No newline at end of file
diff --git a/pregelix/pregelix-example/src/test/resources/jobs/MessageOverflowLSM.xml b/pregelix/pregelix-example/src/test/resources/jobs/MessageOverflowLSM.xml
new file mode 100644
index 0000000..a9f8925
--- /dev/null
+++ b/pregelix/pregelix-example/src/test/resources/jobs/MessageOverflowLSM.xml
@@ -0,0 +1,145 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?><configuration>
+<property><name>mapred.tasktracker.dns.nameserver</name><value>default</value></property>
+<property><name>mapred.queue.default.acl-administer-jobs</name><value>*</value></property>
+<property><name>mapred.skip.map.auto.incr.proc.count</name><value>true</value></property>
+<property><name>mapred.jobtracker.instrumentation</name><value>org.apache.hadoop.mapred.JobTrackerMetricsInst</value></property>
+<property><name>mapred.skip.reduce.auto.incr.proc.count</name><value>true</value></property>
+<property><name>fs.hsftp.impl</name><value>org.apache.hadoop.hdfs.HsftpFileSystem</value></property>
+<property><name>mapred.input.dir</name><value>file:/webmap</value></property>
+<property><name>mapred.submit.replication</name><value>10</value></property>
+<property><name>ipc.server.tcpnodelay</name><value>false</value></property>
+<property><name>fs.checkpoint.dir</name><value>${hadoop.tmp.dir}/dfs/namesecondary</value></property>
+<property><name>mapred.output.compression.type</name><value>RECORD</value></property>
+<property><name>mapred.job.shuffle.merge.percent</name><value>0.66</value></property>
+<property><name>mapred.child.java.opts</name><value>-Xmx200m</value></property>
+<property><name>mapred.queue.default.acl-submit-job</name><value>*</value></property>
+<property><name>keep.failed.task.files</name><value>false</value></property>
+<property><name>mapred.jobtracker.job.history.block.size</name><value>3145728</value></property>
+<property><name>io.bytes.per.checksum</name><value>512</value></property>
+<property><name>mapred.task.tracker.report.address</name><value>127.0.0.1:0</value></property>
+<property><name>hadoop.util.hash.type</name><value>murmur</value></property>
+<property><name>fs.hdfs.impl</name><value>org.apache.hadoop.hdfs.DistributedFileSystem</value></property>
+<property><name>fs.ramfs.impl</name><value>org.apache.hadoop.fs.InMemoryFileSystem</value></property>
+<property><name>mapred.jobtracker.restart.recover</name><value>false</value></property>
+<property><name>fs.hftp.impl</name><value>org.apache.hadoop.hdfs.HftpFileSystem</value></property>
+<property><name>fs.checkpoint.period</name><value>3600</value></property>
+<property><name>mapred.child.tmp</name><value>./tmp</value></property>
+<property><name>mapred.local.dir.minspacekill</name><value>0</value></property>
+<property><name>map.sort.class</name><value>org.apache.hadoop.util.QuickSort</value></property>
+<property><name>hadoop.logfile.count</name><value>10</value></property>
+<property><name>ipc.client.connection.maxidletime</name><value>10000</value></property>
+<property><name>mapred.output.dir</name><value>/result</value></property>
+<property><name>io.map.index.skip</name><value>0</value></property>
+<property><name>mapred.tasktracker.expiry.interval</name><value>600000</value></property>
+<property><name>mapred.output.compress</name><value>false</value></property>
+<property><name>io.seqfile.lazydecompress</name><value>true</value></property>
+<property><name>mapred.reduce.parallel.copies</name><value>5</value></property>
+<property><name>fs.checkpoint.size</name><value>67108864</value></property>
+<property><name>mapred.job.reduce.input.buffer.percent</name><value>0.0</value></property>
+<property><name>mapred.job.name</name><value>Message Overflow LSM</value></property>
+<property><name>pregelix.nmkComputerClass</name><value>edu.uci.ics.pregelix.example.data.VLongNormalizedKeyComputer</value></property>
+<property><name>local.cache.size</name><value>10737418240</value></property>
+<property><name>fs.s3n.impl</name><value>org.apache.hadoop.fs.s3native.NativeS3FileSystem</value></property>
+<property><name>mapred.userlog.limit.kb</name><value>0</value></property>
+<property><name>fs.file.impl</name><value>org.apache.hadoop.fs.LocalFileSystem</value></property>
+<property><name>mapred.task.tracker.http.address</name><value>0.0.0.0:50060</value></property>
+<property><name>mapred.task.timeout</name><value>600000</value></property>
+<property><name>fs.kfs.impl</name><value>org.apache.hadoop.fs.kfs.KosmosFileSystem</value></property>
+<property><name>mapred.max.tracker.blacklists</name><value>4</value></property>
+<property><name>fs.s3.buffer.dir</name><value>${hadoop.tmp.dir}/s3</value></property>
+<property><name>mapred.job.tracker.persist.jobstatus.dir</name><value>/jobtracker/jobsInfo</value></property>
+<property><name>ipc.client.kill.max</name><value>10</value></property>
+<property><name>mapred.tasktracker.instrumentation</name><value>org.apache.hadoop.mapred.TaskTrackerMetricsInst</value></property>
+<property><name>mapred.reduce.tasks.speculative.execution</name><value>true</value></property>
+<property><name>io.sort.record.percent</name><value>0.05</value></property>
+<property><name>hadoop.security.authorization</name><value>false</value></property>
+<property><name>mapred.max.tracker.failures</name><value>4</value></property>
+<property><name>mapred.jobtracker.taskScheduler</name><value>org.apache.hadoop.mapred.JobQueueTaskScheduler</value></property>
+<property><name>pregelix.numVertices</name><value>20</value></property>
+<property><name>mapred.tasktracker.dns.interface</name><value>default</value></property>
+<property><name>mapred.map.tasks</name><value>2</value></property>
+<property><name>mapred.job.tracker.persist.jobstatus.hours</name><value>0</value></property>
+<property><name>fs.s3.sleepTimeSeconds</name><value>10</value></property>
+<property><name>fs.default.name</name><value>file:///</value></property>
+<property><name>tasktracker.http.threads</name><value>40</value></property>
+<property><name>mapred.tasktracker.taskmemorymanager.monitoring-interval</name><value>5000</value></property>
+<property><name>hadoop.rpc.socket.factory.class.default</name><value>org.apache.hadoop.net.StandardSocketFactory</value></property>
+<property><name>mapred.reduce.tasks</name><value>1</value></property>
+<property><name>topology.node.switch.mapping.impl</name><value>org.apache.hadoop.net.ScriptBasedMapping</value></property>
+<property><name>pregelix.vertexClass</name><value>edu.uci.ics.pregelix.example.MessageOverflowVertex</value></property>
+<property><name>mapred.skip.reduce.max.skip.groups</name><value>0</value></property>
+<property><name>io.file.buffer.size</name><value>4096</value></property>
+<property><name>mapred.jobtracker.maxtasks.per.job</name><value>-1</value></property>
+<property><name>mapred.tasktracker.indexcache.mb</name><value>10</value></property>
+<property><name>mapred.tasktracker.map.tasks.maximum</name><value>2</value></property>
+<property><name>fs.har.impl.disable.cache</name><value>true</value></property>
+<property><name>mapred.task.profile.maps</name><value>0-2</value></property>
+<property><name>hadoop.native.lib</name><value>true</value></property>
+<property><name>fs.s3.block.size</name><value>67108864</value></property>
+<property><name>mapred.job.reuse.jvm.num.tasks</name><value>1</value></property>
+<property><name>mapred.job.tracker.http.address</name><value>0.0.0.0:50030</value></property>
+<property><name>mapred.tasktracker.reduce.tasks.maximum</name><value>2</value></property>
+<property><name>io.compression.codecs</name><value>org.apache.hadoop.io.compress.DefaultCodec,org.apache.hadoop.io.compress.GzipCodec,org.apache.hadoop.io.compress.BZip2Codec</value></property>
+<property><name>mapred.job.shuffle.input.buffer.percent</name><value>0.70</value></property>
+<property><name>pregelix.updateIntensive</name><value>true</value></property>
+<property><name>io.seqfile.compress.blocksize</name><value>1000000</value></property>
+<property><name>mapred.queue.names</name><value>default</value></property>
+<property><name>fs.har.impl</name><value>org.apache.hadoop.fs.HarFileSystem</value></property>
+<property><name>io.mapfile.bloom.error.rate</name><value>0.005</value></property>
+<property><name>mapred.job.tracker</name><value>local</value></property>
+<property><name>io.skip.checksum.errors</name><value>false</value></property>
+<property><name>mapred.reduce.max.attempts</name><value>4</value></property>
+<property><name>fs.s3.maxRetries</name><value>4</value></property>
+<property><name>ipc.server.listen.queue.size</name><value>128</value></property>
+<property><name>fs.trash.interval</name><value>0</value></property>
+<property><name>mapred.local.dir.minspacestart</name><value>0</value></property>
+<property><name>fs.s3.impl</name><value>org.apache.hadoop.fs.s3.S3FileSystem</value></property>
+<property><name>io.seqfile.sorter.recordlimit</name><value>1000000</value></property>
+<property><name>io.mapfile.bloom.size</name><value>1048576</value></property>
+<property><name>io.sort.mb</name><value>100</value></property>
+<property><name>mapred.local.dir</name><value>${hadoop.tmp.dir}/mapred/local</value></property>
+<property><name>io.sort.factor</name><value>10</value></property>
+<property><name>mapred.task.profile</name><value>false</value></property>
+<property><name>job.end.retry.interval</name><value>30000</value></property>
+<property><name>mapred.tasktracker.procfsbasedprocesstree.sleeptime-before-sigkill</name><value>5000</value></property>
+<property><name>mapred.jobtracker.completeuserjobs.maximum</name><value>100</value></property>
+<property><name>mapred.task.profile.reduces</name><value>0-2</value></property>
+<property><name>webinterface.private.actions</name><value>false</value></property>
+<property><name>hadoop.tmp.dir</name><value>/tmp/hadoop-${user.name}</value></property>
+<property><name>pregelix.framesize</name><value>2048</value></property>
+<property><name>mapred.output.compression.codec</name><value>org.apache.hadoop.io.compress.DefaultCodec</value></property>
+<property><name>mapred.skip.attempts.to.start.skipping</name><value>2</value></property>
+<property><name>mapred.temp.dir</name><value>${hadoop.tmp.dir}/mapred/temp</value></property>
+<property><name>mapred.merge.recordsBeforeProgress</name><value>10000</value></property>
+<property><name>mapred.map.output.compression.codec</name><value>org.apache.hadoop.io.compress.DefaultCodec</value></property>
+<property><name>mapred.compress.map.output</name><value>false</value></property>
+<property><name>io.sort.spill.percent</name><value>0.80</value></property>
+<property><name>fs.checkpoint.edits.dir</name><value>${fs.checkpoint.dir}</value></property>
+<property><name>mapred.userlog.retain.hours</name><value>24</value></property>
+<property><name>mapred.system.dir</name><value>${hadoop.tmp.dir}/mapred/system</value></property>
+<property><name>mapred.line.input.format.linespermap</name><value>1</value></property>
+<property><name>job.end.retry.attempts</name><value>0</value></property>
+<property><name>ipc.client.idlethreshold</name><value>4000</value></property>
+<property><name>pregelix.vertexOutputFormatClass</name><value>edu.uci.ics.pregelix.example.MessageOverflowVertex$SimpleMessageOverflowVertexOutputFormat</value></property>
+<property><name>mapred.reduce.copy.backoff</name><value>300</value></property>
+<property><name>mapred.map.tasks.speculative.execution</name><value>true</value></property>
+<property><name>mapred.inmem.merge.threshold</name><value>1000</value></property>
+<property><name>hadoop.logfile.size</name><value>10000000</value></property>
+<property><name>pregelix.vertexInputFormatClass</name><value>edu.uci.ics.pregelix.example.inputformat.TextPageRankInputFormat</value></property>
+<property><name>mapred.job.queue.name</name><value>default</value></property>
+<property><name>mapred.job.tracker.persist.jobstatus.active</name><value>false</value></property>
+<property><name>pregelix.incStateLength</name><value>true</value></property>
+<property><name>mapred.reduce.slowstart.completed.maps</name><value>0.05</value></property>
+<property><name>topology.script.number.args</name><value>100</value></property>
+<property><name>mapred.skip.map.max.skip.records</name><value>0</value></property>
+<property><name>fs.ftp.impl</name><value>org.apache.hadoop.fs.ftp.FTPFileSystem</value></property>
+<property><name>mapred.task.cache.levels</name><value>2</value></property>
+<property><name>mapred.job.tracker.handler.count</name><value>10</value></property>
+<property><name>io.serializations</name><value>org.apache.hadoop.io.serializer.WritableSerialization</value></property>
+<property><name>ipc.client.connect.max.retries</name><value>10</value></property>
+<property><name>mapred.min.split.size</name><value>0</value></property>
+<property><name>mapred.map.max.attempts</name><value>4</value></property>
+<property><name>jobclient.output.filter</name><value>FAILED</value></property>
+<property><name>ipc.client.tcpnodelay</name><value>false</value></property>
+<property><name>mapred.acls.enabled</name><value>false</value></property>
+</configuration>
\ No newline at end of file
diff --git a/pregelix/pregelix-example/src/test/resources/jobs/PageRankReal.xml b/pregelix/pregelix-example/src/test/resources/jobs/PageRankReal.xml
index 9e1e0b0..b50b02a 100644
--- a/pregelix/pregelix-example/src/test/resources/jobs/PageRankReal.xml
+++ b/pregelix/pregelix-example/src/test/resources/jobs/PageRankReal.xml
@@ -84,6 +84,7 @@
 <property><name>io.seqfile.compress.blocksize</name><value>1000000</value></property>
 <property><name>mapred.queue.names</name><value>default</value></property>
 <property><name>fs.har.impl</name><value>org.apache.hadoop.fs.HarFileSystem</value></property>
+<property><name>pregelix.checkpointHook</name><value>edu.uci.ics.pregelix.api.util.ConservativeCheckpointHook</value></property>
 <property><name>io.mapfile.bloom.error.rate</name><value>0.005</value></property>
 <property><name>mapred.job.tracker</name><value>local</value></property>
 <property><name>io.skip.checksum.errors</name><value>false</value></property>
diff --git a/pregelix/pregelix-example/src/test/resources/jobs/PageRankRealComplex.xml b/pregelix/pregelix-example/src/test/resources/jobs/PageRankRealComplex.xml
index c4366d7..217fbba 100644
--- a/pregelix/pregelix-example/src/test/resources/jobs/PageRankRealComplex.xml
+++ b/pregelix/pregelix-example/src/test/resources/jobs/PageRankRealComplex.xml
@@ -84,6 +84,7 @@
 <property><name>io.seqfile.compress.blocksize</name><value>1000000</value></property>
 <property><name>mapred.queue.names</name><value>default</value></property>
 <property><name>fs.har.impl</name><value>org.apache.hadoop.fs.HarFileSystem</value></property>
+<property><name>pregelix.checkpointHook</name><value>edu.uci.ics.pregelix.api.util.ConservativeCheckpointHook</value></property>
 <property><name>io.mapfile.bloom.error.rate</name><value>0.005</value></property>
 <property><name>mapred.job.tracker</name><value>local</value></property>
 <property><name>io.skip.checksum.errors</name><value>false</value></property>
diff --git a/pregelix/pregelix-example/src/test/resources/jobs/PageRankRealNoCombiner.xml b/pregelix/pregelix-example/src/test/resources/jobs/PageRankRealNoCombiner.xml
index ac0d508..636b055 100644
--- a/pregelix/pregelix-example/src/test/resources/jobs/PageRankRealNoCombiner.xml
+++ b/pregelix/pregelix-example/src/test/resources/jobs/PageRankRealNoCombiner.xml
@@ -84,6 +84,7 @@
 <property><name>io.seqfile.compress.blocksize</name><value>1000000</value></property>
 <property><name>mapred.queue.names</name><value>default</value></property>
 <property><name>fs.har.impl</name><value>org.apache.hadoop.fs.HarFileSystem</value></property>
+<property><name>pregelix.checkpointHook</name><value>edu.uci.ics.pregelix.api.util.ConservativeCheckpointHook</value></property>
 <property><name>io.mapfile.bloom.error.rate</name><value>0.005</value></property>
 <property><name>mapred.job.tracker</name><value>local</value></property>
 <property><name>io.skip.checksum.errors</name><value>false</value></property>
diff --git a/pregelix/pregelix-runtime/pom.xml b/pregelix/pregelix-runtime/pom.xml
index 54e2256..6564eb0 100644
--- a/pregelix/pregelix-runtime/pom.xml
+++ b/pregelix/pregelix-runtime/pom.xml
@@ -21,7 +21,7 @@
 	<parent>
     		<groupId>edu.uci.ics.hyracks</groupId>
     		<artifactId>pregelix</artifactId>
-    		<version>0.2.7-SNAPSHOT</version>
+    		<version>0.2.10-SNAPSHOT</version>
   	</parent>
 
 
@@ -88,89 +88,89 @@
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>pregelix-api</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>pregelix-dataflow-std</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>pregelix-dataflow</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-dataflow-std</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-api</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-dataflow-common</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-data-std</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-storage-am-common</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-storage-am-btree</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-storage-am-lsm-common</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-control-cc</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-control-nc</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-ipc</artifactId>
-			<version>0.2.7-SNAPSHOT</version>
+			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
diff --git a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/bootstrap/VirtualBufferCacheProvider.java b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/bootstrap/VirtualBufferCacheProvider.java
index ec51047..f15b1c2 100644
--- a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/bootstrap/VirtualBufferCacheProvider.java
+++ b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/bootstrap/VirtualBufferCacheProvider.java
@@ -14,6 +14,8 @@
  */
 package edu.uci.ics.pregelix.runtime.bootstrap;
 
+import java.util.List;
+
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCacheProvider;
@@ -33,7 +35,7 @@
     }
     
     @Override
-    public synchronized IVirtualBufferCache getVirtualBufferCache(IHyracksTaskContext ctx) {
-        return RuntimeContext.get(ctx).getVirtualBufferCache();
+    public synchronized List<IVirtualBufferCache> getVirtualBufferCaches(IHyracksTaskContext ctx) {
+        return RuntimeContext.get(ctx).getVirtualBufferCaches();
     }
 }
diff --git a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/function/ComputeUpdateFunctionFactory.java b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/function/ComputeUpdateFunctionFactory.java
index 16ecf6c..f3a0bb4 100644
--- a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/function/ComputeUpdateFunctionFactory.java
+++ b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/function/ComputeUpdateFunctionFactory.java
@@ -32,8 +32,8 @@
 import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAppender;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
 import edu.uci.ics.pregelix.api.graph.GlobalAggregator;
+import edu.uci.ics.pregelix.api.graph.MsgList;
 import edu.uci.ics.pregelix.api.graph.Vertex;
-import edu.uci.ics.pregelix.api.util.ArrayListWritable;
 import edu.uci.ics.pregelix.api.util.ArrayListWritable.ArrayIterator;
 import edu.uci.ics.pregelix.api.util.BspUtils;
 import edu.uci.ics.pregelix.api.util.FrameTupleUtils;
@@ -168,11 +168,16 @@
                 tbAlive.reset();
 
                 vertex = (Vertex) tuple[3];
+
+                if (vertex.isPartitionTerminated()) {
+                    vertex.voteToHalt();
+                    return;
+                }
                 vertex.setOutputWriters(writers);
                 vertex.setOutputAppenders(appenders);
                 vertex.setOutputTupleBuilders(tbs);
 
-                ArrayListWritable msgContentList = (ArrayListWritable) tuple[1];
+                MsgList msgContentList = (MsgList) tuple[1];
                 msgContentList.reset(msgIterator);
 
                 if (!msgIterator.hasNext() && vertex.isHalted()) {
@@ -183,9 +188,15 @@
                 }
 
                 try {
+                    if (msgContentList.segmentStart()) {
+                        vertex.open();
+                    }
                     vertex.compute(msgIterator);
+                    if (msgContentList.segmentEnd()) {
+                        vertex.close();
+                    }
                     vertex.finishCompute();
-                } catch (IOException e) {
+                } catch (Exception e) {
                     throw new HyracksDataException(e);
                 }
 
@@ -195,7 +206,10 @@
                 if (terminate && (!vertex.isHalted() || vertex.hasMessage() || vertex.createdNewLiveVertex()))
                     terminate = false;
 
-                aggregator.step(vertex);
+                if (msgContentList.segmentEnd()) {
+                    /** the if condition makes sure aggregate only calls once per-vertex */
+                    aggregator.step(vertex);
+                }
             }
 
             @Override
@@ -223,8 +237,12 @@
                     Writable agg = aggregator.finishPartial();
                     agg.write(tbGlobalAggregate.getDataOutput());
                     tbGlobalAggregate.addFieldEndOffset();
-                    appenderGlobalAggregate.append(tbGlobalAggregate.getFieldEndOffsets(),
-                            tbGlobalAggregate.getByteArray(), 0, tbGlobalAggregate.getSize());
+                    if (!appenderGlobalAggregate.append(tbGlobalAggregate.getFieldEndOffsets(),
+                            tbGlobalAggregate.getByteArray(), 0, tbGlobalAggregate.getSize())) {
+                        // aggregate state exceed the page size, write to HDFS
+                        FrameTupleUtils.flushTupleToHDFS(tbGlobalAggregate, conf, Vertex.getSuperstep());
+                        appenderGlobalAggregate.reset(bufferGlobalAggregate, true);
+                    }
                     FrameTupleUtils.flushTuplesFinal(appenderGlobalAggregate, writerGlobalAggregate);
                 } catch (IOException e) {
                     throw new HyracksDataException(e);
diff --git a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/function/StartComputeUpdateFunctionFactory.java b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/function/StartComputeUpdateFunctionFactory.java
index fa7e0a1..ca8ec01 100644
--- a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/function/StartComputeUpdateFunctionFactory.java
+++ b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/function/StartComputeUpdateFunctionFactory.java
@@ -172,24 +172,26 @@
                 tbAlive.reset();
 
                 vertex = (Vertex) tuple[1];
+                if (vertex.isPartitionTerminated()) {
+                    vertex.voteToHalt();
+                    return;
+                }
                 vertex.setOutputWriters(writers);
                 vertex.setOutputAppenders(appenders);
                 vertex.setOutputTupleBuilders(tbs);
 
-                if (!msgIterator.hasNext() && vertex.isHalted()) {
-                    return;
-                }
                 if (vertex.isHalted()) {
                     vertex.activate();
                 }
 
                 try {
+                    vertex.open();
                     vertex.compute(msgIterator);
+                    vertex.close();
                     vertex.finishCompute();
-                } catch (IOException e) {
+                } catch (Exception e) {
                     throw new HyracksDataException(e);
                 }
-
                 /**
                  * this partition should not terminate
                  */
@@ -200,6 +202,7 @@
                  * call the global aggregator
                  */
                 aggregator.step(vertex);
+
             }
 
             @Override
@@ -227,8 +230,12 @@
                     Writable agg = aggregator.finishPartial();
                     agg.write(tbGlobalAggregate.getDataOutput());
                     tbGlobalAggregate.addFieldEndOffset();
-                    appenderGlobalAggregate.append(tbGlobalAggregate.getFieldEndOffsets(),
-                            tbGlobalAggregate.getByteArray(), 0, tbGlobalAggregate.getSize());
+                    if (!appenderGlobalAggregate.append(tbGlobalAggregate.getFieldEndOffsets(),
+                            tbGlobalAggregate.getByteArray(), 0, tbGlobalAggregate.getSize())) {
+                        // aggregate state exceed the page size, write to HDFS
+                        FrameTupleUtils.flushTupleToHDFS(tbGlobalAggregate, conf, Vertex.getSuperstep());
+                        appenderGlobalAggregate.reset(bufferGlobalAggregate, true);
+                    }
                     FrameTupleUtils.flushTuplesFinal(appenderGlobalAggregate, writerGlobalAggregate);
                 } catch (IOException e) {
                     throw new HyracksDataException(e);
diff --git a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AccumulatingAggregatorFactory.java b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AccumulatingAggregatorFactory.java
index 77f28e4..acd766e 100644
--- a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AccumulatingAggregatorFactory.java
+++ b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AccumulatingAggregatorFactory.java
@@ -14,22 +14,27 @@
  */
 package edu.uci.ics.pregelix.runtime.simpleagg;
 
+import java.nio.ByteBuffer;
+
 import org.apache.commons.lang3.tuple.Pair;
 
 import edu.uci.ics.hyracks.api.comm.IFrameTupleAccessor;
+import edu.uci.ics.hyracks.api.comm.IFrameWriter;
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.data.std.util.ArrayBackedValueStorage;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
+import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAppender;
+import edu.uci.ics.hyracks.dataflow.common.comm.util.FrameUtils;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.FrameTupleReference;
 import edu.uci.ics.hyracks.dataflow.std.group.AggregateState;
 import edu.uci.ics.hyracks.dataflow.std.group.IAggregatorDescriptor;
-import edu.uci.ics.hyracks.dataflow.std.group.IAggregatorDescriptorFactory;
+import edu.uci.ics.pregelix.dataflow.group.IClusteredAggregatorDescriptorFactory;
 import edu.uci.ics.pregelix.dataflow.std.base.IAggregateFunction;
 import edu.uci.ics.pregelix.dataflow.std.base.IAggregateFunctionFactory;
 
-public class AccumulatingAggregatorFactory implements IAggregatorDescriptorFactory {
+public class AccumulatingAggregatorFactory implements IClusteredAggregatorDescriptorFactory {
 
     private static final long serialVersionUID = 1L;
     private IAggregateFunctionFactory[] aggFactories;
@@ -41,52 +46,56 @@
     @SuppressWarnings("unchecked")
     @Override
     public IAggregatorDescriptor createAggregator(final IHyracksTaskContext ctx, RecordDescriptor inRecordDesc,
-            RecordDescriptor outRecordDescriptor, int[] aggKeys, int[] partialKeys) throws HyracksDataException {
+            RecordDescriptor outRecordDescriptor, final int[] groupFields, int[] partialgroupFields,
+            final IFrameWriter writer, final ByteBuffer outputFrame, final FrameTupleAppender appender)
+            throws HyracksDataException {
+        final int frameSize = ctx.getFrameSize();
+        final ArrayTupleBuilder internalTupleBuilder = new ArrayTupleBuilder(outRecordDescriptor.getFields().length);
 
         return new IAggregatorDescriptor() {
-
             private FrameTupleReference ftr = new FrameTupleReference();
+            private int groupKeySize = 0;
+            private int metaSlotSize = 4;
+
+            @Override
+            public AggregateState createAggregateStates() {
+                IAggregateFunction[] agg = new IAggregateFunction[aggFactories.length];
+                ArrayBackedValueStorage[] aggOutput = new ArrayBackedValueStorage[aggFactories.length];
+                for (int i = 0; i < agg.length; i++) {
+                    aggOutput[i] = new ArrayBackedValueStorage();
+                    try {
+                        agg[i] = aggFactories[i].createAggregateFunction(ctx, aggOutput[i], writer);
+                    } catch (Exception e) {
+                        throw new IllegalStateException(e);
+                    }
+                }
+                return new AggregateState(Pair.of(aggOutput, agg));
+            }
 
             @Override
             public void init(ArrayTupleBuilder tupleBuilder, IFrameTupleAccessor accessor, int tIndex,
                     AggregateState state) throws HyracksDataException {
-                Pair<ArrayBackedValueStorage[], IAggregateFunction[]> aggState = (Pair<ArrayBackedValueStorage[], IAggregateFunction[]>) state.state;
-                ArrayBackedValueStorage[] aggOutput = aggState.getLeft();
-                IAggregateFunction[] agg = aggState.getRight();
-
-                // initialize aggregate functions
-                for (int i = 0; i < agg.length; i++) {
-                    aggOutput[i].reset();
-                    try {
-                        agg[i].init();
-                    } catch (Exception e) {
-                        throw new HyracksDataException(e);
-                    }
+                setGroupKeySize(accessor, tIndex);
+                initAggregateFunctions(state, true);
+                int stateSize = estimateStep(accessor, tIndex, state);
+                if (stateSize > frameSize) {
+                    throw new HyracksDataException(
+                            "Message combiner intermediate data size "
+                                    + stateSize
+                                    + " is larger than frame size! Check the size estimattion implementation in the message combiner.");
                 }
-
-                ftr.reset(accessor, tIndex);
-                for (int i = 0; i < agg.length; i++) {
-                    try {
-                        agg[i].step(ftr);
-                    } catch (Exception e) {
-                        throw new HyracksDataException(e);
-                    }
-                }
+                singleStep(accessor, tIndex, state);
             }
 
             @Override
             public void aggregate(IFrameTupleAccessor accessor, int tIndex, IFrameTupleAccessor stateAccessor,
                     int stateTupleIndex, AggregateState state) throws HyracksDataException {
-                Pair<ArrayBackedValueStorage[], IAggregateFunction[]> aggState = (Pair<ArrayBackedValueStorage[], IAggregateFunction[]>) state.state;
-                IAggregateFunction[] agg = aggState.getRight();
-                ftr.reset(accessor, tIndex);
-                for (int i = 0; i < agg.length; i++) {
-                    try {
-                        agg[i].step(ftr);
-                    } catch (Exception e) {
-                        throw new HyracksDataException(e);
-                    }
+                int stateSize = estimateStep(accessor, tIndex, state);
+                if (stateSize > frameSize) {
+                    emitResultTuple(accessor, tIndex, state);
+                    initAggregateFunctions(state, false);
                 }
+                singleStep(accessor, tIndex, state);
             }
 
             @Override
@@ -97,7 +106,7 @@
                 IAggregateFunction[] agg = aggState.getRight();
                 for (int i = 0; i < agg.length; i++) {
                     try {
-                        agg[i].finish();
+                        agg[i].finishAll();
                         tupleBuilder.addField(aggOutput[i].getByteArray(), aggOutput[i].getStartOffset(),
                                 aggOutput[i].getLength());
                     } catch (Exception e) {
@@ -107,21 +116,6 @@
             }
 
             @Override
-            public AggregateState createAggregateStates() {
-                IAggregateFunction[] agg = new IAggregateFunction[aggFactories.length];
-                ArrayBackedValueStorage[] aggOutput = new ArrayBackedValueStorage[aggFactories.length];
-                for (int i = 0; i < agg.length; i++) {
-                    aggOutput[i] = new ArrayBackedValueStorage();
-                    try {
-                        agg[i] = aggFactories[i].createAggregateFunction(ctx, aggOutput[i]);
-                    } catch (Exception e) {
-                        throw new IllegalStateException(e);
-                    }
-                }
-                return new AggregateState(Pair.of(aggOutput, agg));
-            }
-
-            @Override
             public void reset() {
 
             }
@@ -137,6 +131,97 @@
 
             }
 
+            private void initAggregateFunctions(AggregateState state, boolean all) throws HyracksDataException {
+                Pair<ArrayBackedValueStorage[], IAggregateFunction[]> aggState = (Pair<ArrayBackedValueStorage[], IAggregateFunction[]>) state.state;
+                ArrayBackedValueStorage[] aggOutput = aggState.getLeft();
+                IAggregateFunction[] agg = aggState.getRight();
+
+                /**
+                 * initialize aggregate functions
+                 */
+                for (int i = 0; i < agg.length; i++) {
+                    aggOutput[i].reset();
+                    try {
+                        if (all) {
+                            agg[i].initAll();
+                        } else {
+                            agg[i].init();
+                        }
+                    } catch (Exception e) {
+                        throw new HyracksDataException(e);
+                    }
+                }
+            }
+
+            private void singleStep(IFrameTupleAccessor accessor, int tIndex, AggregateState state)
+                    throws HyracksDataException {
+                Pair<ArrayBackedValueStorage[], IAggregateFunction[]> aggState = (Pair<ArrayBackedValueStorage[], IAggregateFunction[]>) state.state;
+                IAggregateFunction[] agg = aggState.getRight();
+                ftr.reset(accessor, tIndex);
+                for (int i = 0; i < agg.length; i++) {
+                    try {
+                        agg[i].step(ftr);
+                    } catch (Exception e) {
+                        throw new HyracksDataException(e);
+                    }
+                }
+            }
+
+            private int estimateStep(IFrameTupleAccessor accessor, int tIndex, AggregateState state)
+                    throws HyracksDataException {
+                int size = metaSlotSize + groupKeySize;
+                Pair<ArrayBackedValueStorage[], IAggregateFunction[]> aggState = (Pair<ArrayBackedValueStorage[], IAggregateFunction[]>) state.state;
+                IAggregateFunction[] agg = aggState.getRight();
+                ftr.reset(accessor, tIndex);
+                for (int i = 0; i < agg.length; i++) {
+                    try {
+                        size += agg[i].estimateStep(ftr) + metaSlotSize;
+                    } catch (Exception e) {
+                        throw new HyracksDataException(e);
+                    }
+                }
+                return size * 2;
+            }
+
+            private void emitResultTuple(IFrameTupleAccessor accessor, int tIndex, AggregateState state)
+                    throws HyracksDataException {
+                internalTupleBuilder.reset();
+                for (int j = 0; j < groupFields.length; j++) {
+                    internalTupleBuilder.addField(accessor, tIndex, groupFields[j]);
+                }
+                Pair<ArrayBackedValueStorage[], IAggregateFunction[]> aggState = (Pair<ArrayBackedValueStorage[], IAggregateFunction[]>) state.state;
+                ArrayBackedValueStorage[] aggOutput = aggState.getLeft();
+                IAggregateFunction[] agg = aggState.getRight();
+                for (int i = 0; i < agg.length; i++) {
+                    try {
+                        agg[i].finish();
+                        internalTupleBuilder.addField(aggOutput[i].getByteArray(), aggOutput[i].getStartOffset(),
+                                aggOutput[i].getLength());
+                    } catch (Exception e) {
+                        throw new HyracksDataException(e);
+                    }
+                }
+                if (!appender.appendSkipEmptyField(internalTupleBuilder.getFieldEndOffsets(),
+                        internalTupleBuilder.getByteArray(), 0, internalTupleBuilder.getSize())) {
+                    FrameUtils.flushFrame(outputFrame, writer);
+                    appender.reset(outputFrame, true);
+                    if (!appender.appendSkipEmptyField(internalTupleBuilder.getFieldEndOffsets(),
+                            internalTupleBuilder.getByteArray(), 0, internalTupleBuilder.getSize())) {
+                        throw new HyracksDataException("The output cannot be fit into a frame.");
+                    }
+                }
+            }
+
+            public void setGroupKeySize(IFrameTupleAccessor accessor, int tIndex) {
+                groupKeySize = 0;
+                for (int i = 0; i < groupFields.length; i++) {
+                    int fIndex = groupFields[i];
+                    int fStartOffset = accessor.getFieldStartOffset(tIndex, fIndex);
+                    int fLen = accessor.getFieldEndOffset(tIndex, fIndex) - fStartOffset;
+                    groupKeySize += fLen + metaSlotSize;
+                }
+            }
+
         };
     }
-}
\ No newline at end of file
+}
diff --git a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AggregationFunction.java b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AggregationFunction.java
index 8090dff..5bc30a2 100644
--- a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AggregationFunction.java
+++ b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AggregationFunction.java
@@ -26,6 +26,7 @@
 import org.apache.hadoop.io.WritableComparable;
 
 import edu.uci.ics.hyracks.api.comm.IFrameTupleAccessor;
+import edu.uci.ics.hyracks.api.comm.IFrameWriter;
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.comm.util.ByteBufferInputStream;
@@ -33,6 +34,7 @@
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
 import edu.uci.ics.pregelix.api.graph.MessageCombiner;
 import edu.uci.ics.pregelix.api.graph.MsgList;
+import edu.uci.ics.pregelix.api.io.WritableSizable;
 import edu.uci.ics.pregelix.api.util.BspUtils;
 import edu.uci.ics.pregelix.dataflow.base.IConfigurationFactory;
 import edu.uci.ics.pregelix.dataflow.std.base.IAggregateFunction;
@@ -54,10 +56,11 @@
     private MsgList msgList = new MsgList();
     private boolean keyRead = false;
 
-    public AggregationFunction(IHyracksTaskContext ctx, IConfigurationFactory confFactory, DataOutput output,
-            boolean isFinalStage, boolean partialAggAsInput) throws HyracksDataException {
+    public AggregationFunction(IHyracksTaskContext ctx, IConfigurationFactory confFactory, DataOutput tmpOutput,
+            IFrameWriter groupByOutputWriter, boolean isFinalStage, boolean partialAggAsInput)
+            throws HyracksDataException {
         this.conf = confFactory.createConfiguration(ctx);
-        this.output = output;
+        this.output = tmpOutput;
         this.isFinalStage = isFinalStage;
         this.partialAggAsInput = partialAggAsInput;
         msgList.setConf(this.conf);
@@ -68,6 +71,12 @@
     }
 
     @Override
+    public void initAll() throws HyracksDataException {
+        keyRead = false;
+        combiner.initAll(msgList);
+    }
+
+    @Override
     public void init() throws HyracksDataException {
         keyRead = false;
         combiner.init(msgList);
@@ -75,6 +84,43 @@
 
     @Override
     public void step(IFrameTupleReference tuple) throws HyracksDataException {
+        if (!partialAggAsInput) {
+            combiner.stepPartial(key, (WritableSizable) value);
+        } else {
+            combiner.stepFinal(key, value);
+        }
+    }
+
+    @Override
+    public void finish() throws HyracksDataException {
+        try {
+            if (!isFinalStage) {
+                combinedResult = combiner.finishPartial();
+            } else {
+                combinedResult = combiner.finishFinal();
+            }
+            combinedResult.write(output);
+        } catch (IOException e) {
+            throw new HyracksDataException(e);
+        }
+    }
+
+    @Override
+    public void finishAll() throws HyracksDataException {
+        try {
+            if (!isFinalStage) {
+                combinedResult = combiner.finishPartial();
+            } else {
+                combinedResult = combiner.finishFinalAll();
+            }
+            combinedResult.write(output);
+        } catch (IOException e) {
+            throw new HyracksDataException(e);
+        }
+    }
+
+    @Override
+    public int estimateStep(IFrameTupleReference tuple) throws HyracksDataException {
         FrameTupleReference ftr = (FrameTupleReference) tuple;
         IFrameTupleAccessor fta = ftr.getFrameTupleAccessor();
         ByteBuffer buffer = fta.getBuffer();
@@ -94,28 +140,13 @@
             }
             value.readFields(valueInput);
             if (!partialAggAsInput) {
-                combiner.stepPartial(key, value);
+                return combiner.estimateAccumulatedStateByteSizePartial(key, (WritableSizable) value);
             } else {
-                combiner.stepFinal(key, value);
+                return combiner.estimateAccumulatedStateByteSizeFinal(key, value);
             }
         } catch (IOException e) {
             throw new HyracksDataException(e);
         }
-
-    }
-
-    @Override
-    public void finish() throws HyracksDataException {
-        try {
-            if (!isFinalStage) {
-                combinedResult = combiner.finishPartial();
-            } else {
-                combinedResult = combiner.finishFinal();
-            }
-            combinedResult.write(output);
-        } catch (IOException e) {
-            throw new HyracksDataException(e);
-        }
     }
 
 }
diff --git a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AggregationFunctionFactory.java b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AggregationFunctionFactory.java
index 33dfa5d..54eccf5 100644
--- a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AggregationFunctionFactory.java
+++ b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AggregationFunctionFactory.java
@@ -17,6 +17,7 @@
 
 import java.io.DataOutput;
 
+import edu.uci.ics.hyracks.api.comm.IFrameWriter;
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 import edu.uci.ics.hyracks.data.std.api.IDataOutputProvider;
@@ -37,9 +38,9 @@
     }
 
     @Override
-    public IAggregateFunction createAggregateFunction(IHyracksTaskContext ctx, IDataOutputProvider provider)
-            throws HyracksException {
+    public IAggregateFunction createAggregateFunction(IHyracksTaskContext ctx, IDataOutputProvider provider,
+            IFrameWriter writer) throws HyracksException {
         DataOutput output = provider.getDataOutput();
-        return new AggregationFunction(ctx, confFactory, output, isFinalStage, partialAggAsInput);
+        return new AggregationFunction(ctx, confFactory, output, writer, isFinalStage, partialAggAsInput);
     }
 }
diff --git a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/touchpoint/MsgListNullWriterFactory.java b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/touchpoint/MsgListNullWriterFactory.java
index 4eaa21c..b7689de 100644
--- a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/touchpoint/MsgListNullWriterFactory.java
+++ b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/touchpoint/MsgListNullWriterFactory.java
@@ -32,6 +32,7 @@
             @Override
             public void writeNull(DataOutput out) throws HyracksDataException {
                 try {
+                    out.writeByte(3); //start|end
                     out.writeInt(0);
                 } catch (IOException e) {
                     throw new HyracksDataException(e);
diff --git a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/touchpoint/PreSuperStepRuntimeHookFactory.java b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/touchpoint/PreSuperStepRuntimeHookFactory.java
index 99bcac5..3dcdad2 100644
--- a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/touchpoint/PreSuperStepRuntimeHookFactory.java
+++ b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/touchpoint/PreSuperStepRuntimeHookFactory.java
@@ -26,11 +26,11 @@
 public class PreSuperStepRuntimeHookFactory implements IRuntimeHookFactory {
     private static final long serialVersionUID = 1L;
     private final IConfigurationFactory confFactory;
-    private final String giraphJobId;
+    private final String jobId;
 
-    public PreSuperStepRuntimeHookFactory(String giraphJobId, IConfigurationFactory confFactory) {
+    public PreSuperStepRuntimeHookFactory(String jobId, IConfigurationFactory confFactory) {
         this.confFactory = confFactory;
-        this.giraphJobId = giraphJobId;
+        this.jobId = jobId;
     }
 
     @Override
@@ -40,7 +40,7 @@
             @Override
             public void configure(IHyracksTaskContext ctx) throws HyracksDataException {
                 Configuration conf = confFactory.createConfiguration(ctx);
-                IterationUtils.setProperties(giraphJobId, ctx, conf);
+                IterationUtils.setProperties(jobId, ctx, conf, -1);
             }
 
         };
diff --git a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/touchpoint/RecoveryRuntimeHookFactory.java b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/touchpoint/RecoveryRuntimeHookFactory.java
new file mode 100644
index 0000000..4720272
--- /dev/null
+++ b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/touchpoint/RecoveryRuntimeHookFactory.java
@@ -0,0 +1,57 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.pregelix.runtime.touchpoint;
+
+import org.apache.hadoop.conf.Configuration;
+
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.pregelix.dataflow.base.IConfigurationFactory;
+import edu.uci.ics.pregelix.dataflow.std.base.IRuntimeHook;
+import edu.uci.ics.pregelix.dataflow.std.base.IRuntimeHookFactory;
+import edu.uci.ics.pregelix.dataflow.util.IterationUtils;
+
+/**
+ * Recover the pregelix job state in a NC
+ * 
+ * @author yingyib
+ */
+public class RecoveryRuntimeHookFactory implements IRuntimeHookFactory {
+    private static final long serialVersionUID = 1L;
+    private final long currentSuperStep;
+    private String jobId;
+    private IConfigurationFactory confFactory;
+
+    public RecoveryRuntimeHookFactory(String jobId, long currentSuperStep, IConfigurationFactory confFactory) {
+        this.currentSuperStep = currentSuperStep;
+        this.jobId = jobId;
+        this.confFactory = confFactory;
+    }
+
+    @Override
+    public IRuntimeHook createRuntimeHook() {
+        return new IRuntimeHook() {
+
+            @Override
+            public void configure(IHyracksTaskContext ctx) throws HyracksDataException {
+                IterationUtils.endSuperStep(jobId, ctx);
+                Configuration conf = confFactory.createConfiguration(ctx);
+                IterationUtils.recoverProperties(jobId, ctx, conf, currentSuperStep);
+            }
+
+        };
+    }
+
+}