diff --git a/hyracks/hyracks-storage-am-invertedindex/.settings/org.eclipse.jdt.core.prefs b/hyracks/hyracks-storage-am-invertedindex/.settings/org.eclipse.jdt.core.prefs
deleted file mode 100644
index 1e91fb3..0000000
--- a/hyracks/hyracks-storage-am-invertedindex/.settings/org.eclipse.jdt.core.prefs
+++ /dev/null
@@ -1,6 +0,0 @@
-#Thu May 05 14:44:24 PDT 2011
-eclipse.preferences.version=1
-org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.6
-org.eclipse.jdt.core.compiler.compliance=1.6
-org.eclipse.jdt.core.compiler.problem.forbiddenReference=warning
-org.eclipse.jdt.core.compiler.source=1.6
diff --git a/hyracks/hyracks-storage-am-invertedindex/.settings/org.maven.ide.eclipse.prefs b/hyracks/hyracks-storage-am-invertedindex/.settings/org.maven.ide.eclipse.prefs
deleted file mode 100644
index e5e549a..0000000
--- a/hyracks/hyracks-storage-am-invertedindex/.settings/org.maven.ide.eclipse.prefs
+++ /dev/null
@@ -1,9 +0,0 @@
-#Thu May 05 14:44:18 PDT 2011
-activeProfiles=
-eclipse.preferences.version=1
-fullBuildGoals=process-test-resources
-includeModules=false
-resolveWorkspaceProjects=true
-resourceFilterGoals=process-resources resources\:testResources
-skipCompilerPlugin=true
-version=1
diff --git a/hyracks/hyracks-storage-am-invertedindex/pom.xml b/hyracks/hyracks-storage-am-invertedindex/pom.xml
index c9bbe20..32ce735 100644
--- a/hyracks/hyracks-storage-am-invertedindex/pom.xml
+++ b/hyracks/hyracks-storage-am-invertedindex/pom.xml
@@ -2,12 +2,12 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>edu.uci.ics.hyracks</groupId>
   <artifactId>hyracks-storage-am-invertedindex</artifactId>
-  <version>0.1.9-SNAPSHOT</version>
+  <version>0.2.0-SNAPSHOT</version>
 
   <parent>
     <groupId>edu.uci.ics.hyracks</groupId>
     <artifactId>hyracks</artifactId>
-    <version>0.1.9-SNAPSHOT</version>
+    <version>0.2.0-SNAPSHOT</version>
   </parent>
 
   <build>
@@ -27,35 +27,35 @@
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-common</artifactId>
-  		<version>0.1.9-SNAPSHOT</version>
+  		<version>0.2.0-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>  	
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-dataflow-common</artifactId>
-  		<version>0.1.9-SNAPSHOT</version>
+  		<version>0.2.0-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>  	
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-dataflow-std</artifactId>
-  		<version>0.1.9-SNAPSHOT</version>
+  		<version>0.2.0-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>  	
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-control-nc</artifactId>
-  		<version>0.1.9-SNAPSHOT</version>
+  		<version>0.2.0-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>  	
   	<dependency>
   		<groupId>edu.uci.ics.hyracks</groupId>
   		<artifactId>hyracks-storage-am-btree</artifactId>
-  		<version>0.1.9-SNAPSHOT</version>
+  		<version>0.2.0-SNAPSHOT</version>
   		<type>jar</type>
   		<scope>compile</scope>
   	</dependency>    
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/api/IInvertedIndexOperatorDescriptorHelper.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/api/IInvertedIndexOperatorDescriptor.java
similarity index 60%
rename from hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/api/IInvertedIndexOperatorDescriptorHelper.java
rename to hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/api/IInvertedIndexOperatorDescriptor.java
index b3afe4a..1dc753e 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/api/IInvertedIndexOperatorDescriptorHelper.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/api/IInvertedIndexOperatorDescriptor.java
@@ -16,18 +16,14 @@
 package edu.uci.ics.hyracks.storage.am.invertedindex.api;
 
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
-import edu.uci.ics.hyracks.api.dataflow.value.ITypeTrait;
+import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.dataflow.std.file.IFileSplitProvider;
-import edu.uci.ics.hyracks.storage.am.common.dataflow.ITreeIndexOperatorDescriptorHelper;
-import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexRegistryProvider;
-import edu.uci.ics.hyracks.storage.am.invertedindex.impls.InvertedIndex;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.ITreeIndexOperatorDescriptor;
 
-public interface IInvertedIndexOperatorDescriptorHelper extends ITreeIndexOperatorDescriptorHelper {
-    public IFileSplitProvider getInvIndexFileSplitProvider();
+public interface IInvertedIndexOperatorDescriptor extends ITreeIndexOperatorDescriptor {
+    public IBinaryComparatorFactory[] getInvListsComparatorFactories();
 
-    public IBinaryComparatorFactory[] getInvIndexComparatorFactories();
-
-    public ITypeTrait[] getInvIndexTypeTraits();
-
-    public IIndexRegistryProvider<InvertedIndex> getInvIndexRegistryProvider();
+    public ITypeTraits[] getInvListsTypeTraits();
+    
+    public IFileSplitProvider getInvListsFileSplitProvider();
 }
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/api/IInvertedIndexSearchModifierFactory.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/api/IInvertedIndexSearchModifierFactory.java
new file mode 100644
index 0000000..92770d6
--- /dev/null
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/api/IInvertedIndexSearchModifierFactory.java
@@ -0,0 +1,22 @@
+/*
+ * Copyright 2009-2010 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.invertedindex.api;
+
+import java.io.Serializable;
+
+public interface IInvertedIndexSearchModifierFactory extends Serializable {
+    public IInvertedIndexSearchModifier createSearchModifier();
+}
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/AbstractInvertedIndexOperatorDescriptor.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/AbstractInvertedIndexOperatorDescriptor.java
index 554f0d0..eab266d 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/AbstractInvertedIndexOperatorDescriptor.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/AbstractInvertedIndexOperatorDescriptor.java
@@ -16,79 +16,86 @@
 package edu.uci.ics.hyracks.storage.am.invertedindex.dataflow;
 
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
-import edu.uci.ics.hyracks.api.dataflow.value.ITypeTrait;
+import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.job.JobSpecification;
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractSingleActivityOperatorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.file.IFileSplitProvider;
-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.btree.frames.BTreeNSMInteriorFrameFactory;
+import edu.uci.ics.hyracks.storage.am.btree.frames.BTreeNSMLeafFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrameFactory;
+import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexTupleWriterFactory;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndex;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexDataflowHelperFactory;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexRegistryProvider;
-import edu.uci.ics.hyracks.storage.am.common.dataflow.ITreeIndexOpHelperFactory;
-import edu.uci.ics.hyracks.storage.am.invertedindex.api.IInvertedIndexOperatorDescriptorHelper;
-import edu.uci.ics.hyracks.storage.am.invertedindex.impls.InvertedIndex;
+import edu.uci.ics.hyracks.storage.am.common.tuples.TypeAwareTupleWriterFactory;
+import edu.uci.ics.hyracks.storage.am.invertedindex.api.IInvertedIndexOperatorDescriptor;
+import edu.uci.ics.hyracks.storage.am.invertedindex.util.InvertedIndexUtils;
 import edu.uci.ics.hyracks.storage.common.IStorageManagerInterface;
 
 public abstract class AbstractInvertedIndexOperatorDescriptor extends AbstractSingleActivityOperatorDescriptor
-        implements IInvertedIndexOperatorDescriptorHelper {
+        implements IInvertedIndexOperatorDescriptor {
 
     private static final long serialVersionUID = 1L;
 
-    // general
+    // General.
     protected final IStorageManagerInterface storageManager;
+    protected final IIndexRegistryProvider<IIndex> indexRegistryProvider;
 
-    // btree
-    protected final IFileSplitProvider btreeFileSplitProvider;
-    protected final IIndexRegistryProvider<ITreeIndex> treeIndexRegistryProvider;
-    protected final ITreeIndexFrameFactory interiorFrameFactory;
-    protected final ITreeIndexFrameFactory leafFrameFactory;
-    protected final ITypeTrait[] btreeTypeTraits;
+    // Btree.
+    protected final ITreeIndexFrameFactory btreeInteriorFrameFactory;
+    protected final ITreeIndexFrameFactory btreeLeafFrameFactory;
+    protected final ITypeTraits[] btreeTypeTraits;
     protected final IBinaryComparatorFactory[] btreeComparatorFactories;
-    protected final ITreeIndexOpHelperFactory opHelperFactory;
+    protected final IIndexDataflowHelperFactory btreeDataflowHelperFactory;
+    protected final IFileSplitProvider btreeFileSplitProvider;
 
-    // inverted index
-    protected final IFileSplitProvider invIndexFileSplitProvider;
-    protected final IIndexRegistryProvider<InvertedIndex> invIndexRegistryProvider;
-    protected final ITypeTrait[] invIndexTypeTraits;
-    protected final IBinaryComparatorFactory[] invIndexComparatorFactories;
+    // Inverted index.
+    protected final ITypeTraits[] invListsTypeTraits;
+    protected final IBinaryComparatorFactory[] invListComparatorFactories;
+    protected final IFileSplitProvider invListsFileSplitProvider;
 
     public AbstractInvertedIndexOperatorDescriptor(JobSpecification spec, int inputArity, int outputArity,
             RecordDescriptor recDesc, IStorageManagerInterface storageManager,
-            IFileSplitProvider btreeFileSplitProvider, IIndexRegistryProvider<ITreeIndex> treeIndexRegistryProvider,
-            ITreeIndexFrameFactory interiorFrameFactory, ITreeIndexFrameFactory leafFrameFactory,
-            ITypeTrait[] btreeTypeTraits, IBinaryComparatorFactory[] btreeComparatorFactories, float btreeFillFactor,
-            ITreeIndexOpHelperFactory opHelperFactory, IFileSplitProvider invIndexFileSplitProvider,
-            IIndexRegistryProvider<InvertedIndex> invIndexRegistryProvider, ITypeTrait[] invIndexTypeTraits,
-            IBinaryComparatorFactory[] invIndexComparatorFactories) {
+            IFileSplitProvider btreeFileSplitProvider, IFileSplitProvider invListsFileSplitProvider,
+            IIndexRegistryProvider<IIndex> indexRegistryProvider, ITypeTraits[] tokenTypeTraits,
+            IBinaryComparatorFactory[] tokenComparatorFactories, ITypeTraits[] invListsTypeTraits,
+            IBinaryComparatorFactory[] invListComparatorFactories,
+            IIndexDataflowHelperFactory btreeDataflowHelperFactory) {
         super(spec, inputArity, outputArity);
 
-        // general
+        // General.
         this.storageManager = storageManager;
+        this.indexRegistryProvider = indexRegistryProvider;
 
-        // btree
+        // Btree.
+        this.btreeTypeTraits = InvertedIndexUtils.getBTreeTypeTraits(tokenTypeTraits);
+        ITreeIndexTupleWriterFactory tupleWriterFactory = new TypeAwareTupleWriterFactory(btreeTypeTraits);
+        this.btreeInteriorFrameFactory = new BTreeNSMInteriorFrameFactory(tupleWriterFactory);
+        this.btreeLeafFrameFactory = new BTreeNSMLeafFrameFactory(tupleWriterFactory);
+        this.btreeComparatorFactories = tokenComparatorFactories;
+        this.btreeDataflowHelperFactory = btreeDataflowHelperFactory;
         this.btreeFileSplitProvider = btreeFileSplitProvider;
-        this.treeIndexRegistryProvider = treeIndexRegistryProvider;
-        this.interiorFrameFactory = interiorFrameFactory;
-        this.leafFrameFactory = leafFrameFactory;
-        this.btreeTypeTraits = btreeTypeTraits;
-        this.btreeComparatorFactories = btreeComparatorFactories;
-        this.opHelperFactory = opHelperFactory;
 
-        // inverted index
-        this.invIndexFileSplitProvider = invIndexFileSplitProvider;
-        this.invIndexRegistryProvider = invIndexRegistryProvider;
-        this.invIndexTypeTraits = invIndexTypeTraits;
-        this.invIndexComparatorFactories = invIndexComparatorFactories;
+        // Inverted index.
+        this.invListsTypeTraits = invListsTypeTraits;
+        this.invListComparatorFactories = invListComparatorFactories;
+        this.invListsFileSplitProvider = invListsFileSplitProvider;
 
-        if (outputArity > 0)
+        if (outputArity > 0) {
             recordDescriptors[0] = recDesc;
+        }
     }
 
     @Override
-    public IFileSplitProvider getTreeIndexFileSplitProvider() {
+    public IFileSplitProvider getFileSplitProvider() {
         return btreeFileSplitProvider;
     }
+    
+    @Override
+    public IFileSplitProvider getInvListsFileSplitProvider() {
+        return invListsFileSplitProvider;
+    }
 
     @Override
     public IBinaryComparatorFactory[] getTreeIndexComparatorFactories() {
@@ -96,23 +103,18 @@
     }
 
     @Override
-    public IPrimitiveValueProviderFactory[] getTreeIndexValueProviderFactories() {
-        return null;
-    }
-
-    @Override
-    public ITypeTrait[] getTreeIndexTypeTraits() {
+    public ITypeTraits[] getTreeIndexTypeTraits() {
         return btreeTypeTraits;
     }
 
     @Override
     public ITreeIndexFrameFactory getTreeIndexInteriorFactory() {
-        return interiorFrameFactory;
+        return btreeInteriorFrameFactory;
     }
 
     @Override
     public ITreeIndexFrameFactory getTreeIndexLeafFactory() {
-        return leafFrameFactory;
+        return btreeLeafFrameFactory;
     }
 
     @Override
@@ -121,37 +123,27 @@
     }
 
     @Override
-    public IIndexRegistryProvider<ITreeIndex> getTreeIndexRegistryProvider() {
-        return treeIndexRegistryProvider;
-    }
-
-    @Override
     public RecordDescriptor getRecordDescriptor() {
         return recordDescriptors[0];
     }
 
     @Override
-    public IIndexRegistryProvider<InvertedIndex> getInvIndexRegistryProvider() {
-        return invIndexRegistryProvider;
+    public IBinaryComparatorFactory[] getInvListsComparatorFactories() {
+        return invListComparatorFactories;
     }
 
     @Override
-    public IBinaryComparatorFactory[] getInvIndexComparatorFactories() {
-        return invIndexComparatorFactories;
+    public ITypeTraits[] getInvListsTypeTraits() {
+        return invListsTypeTraits;
     }
 
     @Override
-    public IFileSplitProvider getInvIndexFileSplitProvider() {
-        return invIndexFileSplitProvider;
+    public IIndexRegistryProvider<IIndex> getIndexRegistryProvider() {
+        return indexRegistryProvider;
     }
-
+    
     @Override
-    public ITypeTrait[] getInvIndexTypeTraits() {
-        return invIndexTypeTraits;
+    public IIndexDataflowHelperFactory getIndexDataflowHelperFactory() {
+        return btreeDataflowHelperFactory;
     }
-
-    @Override
-    public ITreeIndexOpHelperFactory getTreeIndexOpHelperFactory() {
-        return opHelperFactory;
-    }
-}
+}
\ No newline at end of file
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/BinaryTokenizerOperatorDescriptor.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/BinaryTokenizerOperatorDescriptor.java
index 83246d6..ffb94e7 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/BinaryTokenizerOperatorDescriptor.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/BinaryTokenizerOperatorDescriptor.java
@@ -15,12 +15,11 @@
 
 package edu.uci.ics.hyracks.storage.am.invertedindex.dataflow;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+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.IOperatorEnvironment;
 import edu.uci.ics.hyracks.api.job.JobSpecification;
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractSingleActivityOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.invertedindex.tokenizers.IBinaryTokenizerFactory;
@@ -30,26 +29,26 @@
     private static final long serialVersionUID = 1L;
 
     private final IBinaryTokenizerFactory tokenizerFactory;
-    // fields that will be tokenized
+    // Fields that will be tokenized
     private final int[] tokenFields;
-    // operator will emit these projected fields for each token, e.g., as
+    // operator will append these key fields to each token, e.g., as
     // payload for an inverted list
-    // WARNING: too many projected fields can cause significant data blowup
-    private final int[] projFields;
+    // WARNING: too many key fields can cause significant data blowup.
+    private final int[] keyFields;
 
     public BinaryTokenizerOperatorDescriptor(JobSpecification spec, RecordDescriptor recDesc,
-            IBinaryTokenizerFactory tokenizerFactory, int[] tokenFields, int[] projFields) {
+            IBinaryTokenizerFactory tokenizerFactory, int[] tokenFields, int[] keyFields) {
         super(spec, 1, 1);
         this.tokenizerFactory = tokenizerFactory;
         this.tokenFields = tokenFields;
-        this.projFields = projFields;
+        this.keyFields = keyFields;
         recordDescriptors[0] = recDesc;
     }
 
     @Override
-    public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, IOperatorEnvironment env,
-            IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) throws HyracksDataException {
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, IRecordDescriptorProvider recordDescProvider,
+            int partition, int nPartitions) throws HyracksDataException {
         return new BinaryTokenizerOperatorNodePushable(ctx, recordDescProvider.getInputRecordDescriptor(odId, 0),
-                recordDescriptors[0], tokenizerFactory.createTokenizer(), tokenFields, projFields);
+                recordDescriptors[0], tokenizerFactory.createTokenizer(), tokenFields, keyFields);
     }
 }
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/BinaryTokenizerOperatorNodePushable.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/BinaryTokenizerOperatorNodePushable.java
index 0647f45..d00bea6 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/BinaryTokenizerOperatorNodePushable.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/BinaryTokenizerOperatorNodePushable.java
@@ -19,7 +19,7 @@
 import java.io.IOException;
 import java.nio.ByteBuffer;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+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.ArrayTupleBuilder;
@@ -32,7 +32,7 @@
 
 public class BinaryTokenizerOperatorNodePushable extends AbstractUnaryInputUnaryOutputOperatorNodePushable {
 
-    private final IHyracksStageletContext ctx;
+    private final IHyracksTaskContext ctx;
     private final IBinaryTokenizer tokenizer;
     private final int[] tokenFields;
     private final int[] projFields;
@@ -45,7 +45,7 @@
     private FrameTupleAppender appender;
     private ByteBuffer writeBuffer;
 
-    public BinaryTokenizerOperatorNodePushable(IHyracksStageletContext ctx, RecordDescriptor inputRecDesc,
+    public BinaryTokenizerOperatorNodePushable(IHyracksTaskContext ctx, RecordDescriptor inputRecDesc,
             RecordDescriptor outputRecDesc, IBinaryTokenizer tokenizer, int[] tokenFields, int[] projFields) {
         this.ctx = ctx;
         this.tokenizer = tokenizer;
@@ -59,10 +59,11 @@
     public void open() throws HyracksDataException {
         accessor = new FrameTupleAccessor(ctx.getFrameSize(), inputRecDesc);
         writeBuffer = ctx.allocateFrame();
-        builder = new ArrayTupleBuilder(outputRecDesc.getFields().length);
+        builder = new ArrayTupleBuilder(outputRecDesc.getFieldCount());
         builderDos = builder.getDataOutput();
         appender = new FrameTupleAppender(ctx.getFrameSize());
         appender.reset(writeBuffer, true);
+        writer.open();
     }
 
     @Override
@@ -119,6 +120,7 @@
     }
 
     @Override
-    public void flush() throws HyracksDataException {
+    public void fail() throws HyracksDataException {
+        writer.fail();
     }
 }
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/InvertedIndexBulkLoadOperatorDescriptor.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/InvertedIndexBulkLoadOperatorDescriptor.java
index d003580..e91aa08 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/InvertedIndexBulkLoadOperatorDescriptor.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/InvertedIndexBulkLoadOperatorDescriptor.java
@@ -15,20 +15,16 @@
 
 package edu.uci.ics.hyracks.storage.am.invertedindex.dataflow;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+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.ITypeTrait;
-import edu.uci.ics.hyracks.api.job.IOperatorEnvironment;
+import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.api.job.JobSpecification;
 import edu.uci.ics.hyracks.dataflow.std.file.IFileSplitProvider;
-import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
-import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrameFactory;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndex;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexDataflowHelperFactory;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexRegistryProvider;
-import edu.uci.ics.hyracks.storage.am.common.dataflow.ITreeIndexOpHelperFactory;
-import edu.uci.ics.hyracks.storage.am.invertedindex.api.IInvertedListBuilder;
-import edu.uci.ics.hyracks.storage.am.invertedindex.impls.InvertedIndex;
 import edu.uci.ics.hyracks.storage.common.IStorageManagerInterface;
 
 public class InvertedIndexBulkLoadOperatorDescriptor extends AbstractInvertedIndexOperatorDescriptor {
@@ -36,30 +32,22 @@
     private static final long serialVersionUID = 1L;
 
     private final int[] fieldPermutation;
-    private final float btreeFillFactor;
-    private final IInvertedListBuilder invListBuilder;
 
-    public InvertedIndexBulkLoadOperatorDescriptor(JobSpecification spec, IStorageManagerInterface storageManager,
-            int[] fieldPermutation, IFileSplitProvider btreeFileSplitProvider,
-            IIndexRegistryProvider<ITreeIndex> treeIndexRegistryProvider, ITreeIndexFrameFactory interiorFrameFactory,
-            ITreeIndexFrameFactory leafFrameFactory, ITypeTrait[] btreeTypeTraits,
-            IBinaryComparatorFactory[] btreeComparatorFactories, float btreeFillFactor,
-            ITreeIndexOpHelperFactory opHelperFactory, IFileSplitProvider invIndexFileSplitProvider,
-            IIndexRegistryProvider<InvertedIndex> invIndexRegistryProvider, ITypeTrait[] invIndexTypeTraits,
-            IBinaryComparatorFactory[] invIndexComparatorFactories, IInvertedListBuilder invListBuilder) {
-        super(spec, 1, 0, null, storageManager, btreeFileSplitProvider, treeIndexRegistryProvider,
-                interiorFrameFactory, leafFrameFactory, btreeTypeTraits, btreeComparatorFactories, btreeFillFactor,
-                opHelperFactory, invIndexFileSplitProvider, invIndexRegistryProvider, invIndexTypeTraits,
-                invIndexComparatorFactories);
+    public InvertedIndexBulkLoadOperatorDescriptor(JobSpecification spec, int[] fieldPermutation,
+            IStorageManagerInterface storageManager, IFileSplitProvider btreeFileSplitProvider,
+            IFileSplitProvider invListsFileSplitProvider, IIndexRegistryProvider<IIndex> indexRegistryProvider,
+            ITypeTraits[] tokenTypeTraits, IBinaryComparatorFactory[] tokenComparatorFactories,
+            ITypeTraits[] invListsTypeTraits, IBinaryComparatorFactory[] invListComparatorFactories,
+            IIndexDataflowHelperFactory btreeDataflowHelperFactory) {
+        super(spec, 1, 0, null, storageManager, btreeFileSplitProvider, invListsFileSplitProvider,
+                indexRegistryProvider, tokenTypeTraits, tokenComparatorFactories, invListsTypeTraits,
+                invListComparatorFactories, btreeDataflowHelperFactory);
         this.fieldPermutation = fieldPermutation;
-        this.btreeFillFactor = btreeFillFactor;
-        this.invListBuilder = invListBuilder;
     }
 
     @Override
-    public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx,
             IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
-        return new InvertedIndexBulkLoadOperatorNodePushable(this, ctx, partition, fieldPermutation, btreeFillFactor,
-                invListBuilder, recordDescProvider);
+        return new InvertedIndexBulkLoadOperatorNodePushable(this, ctx, partition, fieldPermutation, recordDescProvider);
     }
 }
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/InvertedIndexBulkLoadOperatorNodePushable.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/InvertedIndexBulkLoadOperatorNodePushable.java
index 4969124..9dcabb4 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/InvertedIndexBulkLoadOperatorNodePushable.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/InvertedIndexBulkLoadOperatorNodePushable.java
@@ -16,27 +16,28 @@
 
 import java.nio.ByteBuffer;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 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.dataflow.common.comm.io.FrameTupleAccessor;
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractUnaryInputSinkOperatorNodePushable;
-import edu.uci.ics.hyracks.storage.am.common.dataflow.IndexHelperOpenMode;
+import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
+import edu.uci.ics.hyracks.storage.am.common.api.PageAllocationException;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.PermutingFrameTupleReference;
-import edu.uci.ics.hyracks.storage.am.common.dataflow.TreeIndexOpHelper;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.TreeIndexDataflowHelper;
 import edu.uci.ics.hyracks.storage.am.invertedindex.api.IInvertedListBuilder;
+import edu.uci.ics.hyracks.storage.am.invertedindex.impls.FixedSizeElementInvertedListBuilder;
 import edu.uci.ics.hyracks.storage.am.invertedindex.impls.InvertedIndex;
 
 public class InvertedIndexBulkLoadOperatorNodePushable extends AbstractUnaryInputSinkOperatorNodePushable {
-    private final TreeIndexOpHelper treeIndexOpHelper;
-    private float btreeFillFactor;
-
-    private final InvertedIndexOpHelper invIndexOpHelper;
-    protected final IInvertedListBuilder invListBuilder;
+    private final TreeIndexDataflowHelper btreeDataflowHelper;
+    private final InvertedIndexDataflowHelper invIndexDataflowHelper;
+    private final IInvertedListBuilder invListBuilder;
+    private InvertedIndex invIndex;
     private InvertedIndex.BulkLoadContext bulkLoadCtx;
 
-    private final IHyracksStageletContext ctx;
+    private final IHyracksTaskContext ctx;
 
     private FrameTupleAccessor accessor;
     private PermutingFrameTupleReference tuple = new PermutingFrameTupleReference();
@@ -44,45 +45,49 @@
     private IRecordDescriptorProvider recordDescProvider;
 
     public InvertedIndexBulkLoadOperatorNodePushable(AbstractInvertedIndexOperatorDescriptor opDesc,
-            IHyracksStageletContext ctx, int partition, int[] fieldPermutation, float btreeFillFactor,
-            IInvertedListBuilder invListBuilder, IRecordDescriptorProvider recordDescProvider) {
-        treeIndexOpHelper = opDesc.getTreeIndexOpHelperFactory().createTreeIndexOpHelper(opDesc, ctx, partition,
-                IndexHelperOpenMode.CREATE);
-        invIndexOpHelper = new InvertedIndexOpHelper(opDesc, ctx, partition, IndexHelperOpenMode.CREATE);
-        this.btreeFillFactor = btreeFillFactor;
+            IHyracksTaskContext ctx, int partition, int[] fieldPermutation, IRecordDescriptorProvider recordDescProvider) {
+        btreeDataflowHelper = (TreeIndexDataflowHelper) opDesc.getIndexDataflowHelperFactory()
+                .createIndexDataflowHelper(opDesc, ctx, partition, true);
+        invIndexDataflowHelper = new InvertedIndexDataflowHelper(btreeDataflowHelper, opDesc, ctx, partition, true);
         this.recordDescProvider = recordDescProvider;
         this.ctx = ctx;
-        this.invListBuilder = invListBuilder;
+        this.invListBuilder = new FixedSizeElementInvertedListBuilder(opDesc.getInvListsTypeTraits());
         tuple.setFieldPermutation(fieldPermutation);
     }
 
     @Override
     public void open() throws HyracksDataException {
-        AbstractInvertedIndexOperatorDescriptor opDesc = (AbstractInvertedIndexOperatorDescriptor) treeIndexOpHelper
+        AbstractInvertedIndexOperatorDescriptor opDesc = (AbstractInvertedIndexOperatorDescriptor) btreeDataflowHelper
                 .getOperatorDescriptor();
         RecordDescriptor recDesc = recordDescProvider.getInputRecordDescriptor(opDesc.getOperatorId(), 0);
-        accessor = new FrameTupleAccessor(treeIndexOpHelper.getHyracksStageletContext().getFrameSize(), recDesc);
+        accessor = new FrameTupleAccessor(btreeDataflowHelper.getHyracksTaskContext().getFrameSize(), recDesc);
 
-        // btree
+        // BTree.
         try {
-            treeIndexOpHelper.init();
-            treeIndexOpHelper.getTreeIndex().open(treeIndexOpHelper.getIndexFileId());
+            btreeDataflowHelper.init();
         } catch (Exception e) {
-            // cleanup in case of failure
-            treeIndexOpHelper.deinit();
-            throw new HyracksDataException(e);
+            // Cleanup in case of failure.
+            btreeDataflowHelper.deinit();
+            if (e instanceof HyracksDataException) {
+                throw (HyracksDataException) e;
+            } else {
+                throw new HyracksDataException(e);
+            }
         }
 
-        // inverted index
+        // Inverted Index.
         try {
-            invIndexOpHelper.init();
-            invIndexOpHelper.getInvIndex().open(invIndexOpHelper.getInvIndexFileId());
-            bulkLoadCtx = invIndexOpHelper.getInvIndex().beginBulkLoad(invListBuilder, ctx.getFrameSize(),
-                    btreeFillFactor);
+            invIndexDataflowHelper.init();
+            invIndex = (InvertedIndex) invIndexDataflowHelper.getIndex();
+            bulkLoadCtx = invIndex.beginBulkLoad(invListBuilder, ctx.getFrameSize(), BTree.DEFAULT_FILL_FACTOR);
         } catch (Exception e) {
-            // cleanup in case of failure
-            invIndexOpHelper.deinit();
-            throw new HyracksDataException(e);
+            // Cleanup in case of failure.
+            invIndexDataflowHelper.deinit();
+            if (e instanceof HyracksDataException) {
+                throw (HyracksDataException) e;
+            } else {
+                throw new HyracksDataException(e);
+            }
         }
     }
 
@@ -92,20 +97,30 @@
         int tupleCount = accessor.getTupleCount();
         for (int i = 0; i < tupleCount; i++) {
             tuple.reset(accessor, i);
-            invIndexOpHelper.getInvIndex().bulkLoadAddTuple(bulkLoadCtx, tuple);
+            try {
+                invIndex.bulkLoadAddTuple(bulkLoadCtx, tuple);
+            } catch (PageAllocationException e) {
+                throw new HyracksDataException(e);
+            }
         }
     }
 
     @Override
     public void close() throws HyracksDataException {
         try {
-            invIndexOpHelper.getInvIndex().endBulkLoad(bulkLoadCtx);
+            invIndex.endBulkLoad(bulkLoadCtx);
+        } catch (PageAllocationException e) {
+            throw new HyracksDataException(e);
         } finally {
-            treeIndexOpHelper.deinit();
+            try {
+                btreeDataflowHelper.deinit();
+            } finally {
+                invIndexDataflowHelper.deinit();
+            }
         }
     }
 
     @Override
-    public void flush() throws HyracksDataException {
+    public void fail() throws HyracksDataException {
     }
 }
\ No newline at end of file
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/InvertedIndexDataflowHelper.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/InvertedIndexDataflowHelper.java
new file mode 100644
index 0000000..71717e4
--- /dev/null
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/InvertedIndexDataflowHelper.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright 2009-2010 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.invertedindex.dataflow;
+
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.io.FileReference;
+import edu.uci.ics.hyracks.dataflow.std.file.IFileSplitProvider;
+import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndex;
+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.common.dataflow.TreeIndexDataflowHelper;
+import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
+import edu.uci.ics.hyracks.storage.am.common.util.IndexUtils;
+import edu.uci.ics.hyracks.storage.am.invertedindex.api.IInvertedIndexOperatorDescriptor;
+import edu.uci.ics.hyracks.storage.am.invertedindex.impls.InvertedIndex;
+
+public final class InvertedIndexDataflowHelper extends IndexDataflowHelper {
+    private final TreeIndexDataflowHelper btreeDataflowHelper;
+
+    public InvertedIndexDataflowHelper(TreeIndexDataflowHelper btreeDataflowHelper, IIndexOperatorDescriptor opDesc,
+            IHyracksTaskContext ctx, int partition, boolean createIfNotExists) {
+        super(opDesc, ctx, partition, createIfNotExists);
+        this.btreeDataflowHelper = btreeDataflowHelper;
+    }
+
+    public FileReference getFilereference() {
+        AbstractInvertedIndexOperatorDescriptor invIndexOpDesc = (AbstractInvertedIndexOperatorDescriptor) opDesc;
+        IFileSplitProvider fileSplitProvider = invIndexOpDesc.getInvListsFileSplitProvider();
+        return fileSplitProvider.getFileSplits()[partition].getLocalFile();
+    }
+
+    @Override
+    public IIndex createIndexInstance() throws HyracksDataException {
+        IInvertedIndexOperatorDescriptor invIndexOpDesc = (IInvertedIndexOperatorDescriptor) opDesc;
+        MultiComparator cmp = IndexUtils.createMultiComparator(invIndexOpDesc.getInvListsComparatorFactories());
+        // Assumes btreeDataflowHelper.init() has already been called.
+        BTree btree = (BTree) btreeDataflowHelper.getIndex();
+        return new InvertedIndex(opDesc.getStorageManager().getBufferCache(ctx), btree,
+                invIndexOpDesc.getInvListsTypeTraits(), cmp);
+    }
+}
\ No newline at end of file
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/InvertedIndexOpHelper.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/InvertedIndexOpHelper.java
deleted file mode 100644
index c16cfcd..0000000
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/InvertedIndexOpHelper.java
+++ /dev/null
@@ -1,158 +0,0 @@
-/*
- * Copyright 2009-2010 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.invertedindex.dataflow;
-
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
-import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparator;
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.api.io.FileReference;
-import edu.uci.ics.hyracks.dataflow.std.file.IFileSplitProvider;
-import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
-import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
-import edu.uci.ics.hyracks.storage.am.common.dataflow.ITreeIndexOperatorDescriptorHelper;
-import edu.uci.ics.hyracks.storage.am.common.dataflow.IndexHelperOpenMode;
-import edu.uci.ics.hyracks.storage.am.common.dataflow.IndexRegistry;
-import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
-import edu.uci.ics.hyracks.storage.am.invertedindex.api.IInvertedIndexOperatorDescriptorHelper;
-import edu.uci.ics.hyracks.storage.am.invertedindex.impls.InvertedIndex;
-import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
-import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
-
-public final class InvertedIndexOpHelper {
-
-    private InvertedIndex invIndex;
-    private int invIndexFileId = -1;
-    private int partition;
-
-    private IInvertedIndexOperatorDescriptorHelper opDesc;
-    private IHyracksStageletContext ctx;
-
-    private IndexHelperOpenMode mode;
-
-    public InvertedIndexOpHelper(IInvertedIndexOperatorDescriptorHelper opDesc, final IHyracksStageletContext ctx,
-            int partition, IndexHelperOpenMode mode) {
-        this.opDesc = opDesc;
-        this.ctx = ctx;
-        this.mode = mode;
-        this.partition = partition;
-    }
-
-    public void init() throws HyracksDataException {
-        IBufferCache bufferCache = opDesc.getStorageManager().getBufferCache(ctx);
-        IFileMapProvider fileMapProvider = opDesc.getStorageManager().getFileMapProvider(ctx);
-        IFileSplitProvider fileSplitProvider = opDesc.getInvIndexFileSplitProvider();
-
-        FileReference f = fileSplitProvider.getFileSplits()[partition].getLocalFile();
-        boolean fileIsMapped = fileMapProvider.isMapped(f);
-
-        switch (mode) {
-
-            case OPEN: {
-                if (!fileIsMapped) {
-                    throw new HyracksDataException("Trying to open inverted index from unmapped file " + f.toString());
-                }
-            }
-                break;
-
-            case CREATE:
-            case ENLIST: {
-                if (!fileIsMapped) {
-                    bufferCache.createFile(f);
-                }
-            }
-                break;
-
-        }
-
-        int fileId = fileMapProvider.lookupFileId(f);
-        try {
-            bufferCache.openFile(fileId);
-        } catch (HyracksDataException e) {
-            // revert state of buffer cache since file failed to open
-            if (!fileIsMapped) {
-                bufferCache.deleteFile(fileId);
-            }
-            throw e;
-        }
-
-        // only set btreeFileId member when openFile() succeeds,
-        // otherwise deinit() will try to close the file that failed to open
-        invIndexFileId = fileId;
-        IndexRegistry<InvertedIndex> invIndexRegistry = opDesc.getInvIndexRegistryProvider().getRegistry(ctx);
-        invIndex = invIndexRegistry.get(invIndexFileId);
-        if (invIndex == null) {
-
-            // create new inverted index and register it
-            invIndexRegistry.lock();
-            try {
-                // check if inverted index has already been registered by
-                // another thread
-                invIndex = invIndexRegistry.get(invIndexFileId);
-                if (invIndex == null) {
-                    // this thread should create and register the inverted index
-
-                    IBinaryComparator[] comparators = new IBinaryComparator[opDesc.getInvIndexComparatorFactories().length];
-                    for (int i = 0; i < opDesc.getInvIndexComparatorFactories().length; i++) {
-                        comparators[i] = opDesc.getInvIndexComparatorFactories()[i].createBinaryComparator();
-                    }
-
-                    MultiComparator cmp = new MultiComparator(opDesc.getInvIndexTypeTraits(), comparators);
-
-                    // assumes btree has already been registered
-                    IFileSplitProvider btreeFileSplitProvider = opDesc.getTreeIndexFileSplitProvider();
-                    IndexRegistry<ITreeIndex> treeIndexRegistry = opDesc.getTreeIndexRegistryProvider()
-                            .getRegistry(ctx);
-                    FileReference btreeFile = btreeFileSplitProvider.getFileSplits()[partition].getLocalFile();
-                    boolean btreeFileIsMapped = fileMapProvider.isMapped(btreeFile);
-                    if (!btreeFileIsMapped) {
-                        throw new HyracksDataException(
-                                "Trying to create inverted index, but associated BTree file has not been mapped");
-                    }
-                    int btreeFileId = fileMapProvider.lookupFileId(f);
-                    BTree btree = (BTree) treeIndexRegistry.get(btreeFileId);
-
-                    invIndex = new InvertedIndex(bufferCache, btree, cmp);
-                    invIndex.open(invIndexFileId);
-                    invIndexRegistry.register(invIndexFileId, invIndex);
-                }
-            } finally {
-                invIndexRegistry.unlock();
-            }
-        }
-    }
-
-    public void deinit() throws HyracksDataException {
-        if (invIndexFileId != -1) {
-            IBufferCache bufferCache = opDesc.getStorageManager().getBufferCache(ctx);
-            bufferCache.closeFile(invIndexFileId);
-        }
-    }
-
-    public InvertedIndex getInvIndex() {
-        return invIndex;
-    }
-
-    public IHyracksStageletContext getHyracksStageletContext() {
-        return ctx;
-    }
-
-    public ITreeIndexOperatorDescriptorHelper getOperatorDescriptor() {
-        return opDesc;
-    }
-
-    public int getInvIndexFileId() {
-        return invIndexFileId;
-    }
-}
\ No newline at end of file
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/InvertedIndexSearchOperatorDescriptor.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/InvertedIndexSearchOperatorDescriptor.java
new file mode 100644
index 0000000..bf9899f
--- /dev/null
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/InvertedIndexSearchOperatorDescriptor.java
@@ -0,0 +1,66 @@
+/*
+ * Copyright 2009-2010 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.invertedindex.dataflow;
+
+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.ITypeTraits;
+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.file.IFileSplitProvider;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndex;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexDataflowHelperFactory;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexRegistryProvider;
+import edu.uci.ics.hyracks.storage.am.invertedindex.api.IInvertedIndexSearchModifier;
+import edu.uci.ics.hyracks.storage.am.invertedindex.api.IInvertedIndexSearchModifierFactory;
+import edu.uci.ics.hyracks.storage.am.invertedindex.tokenizers.IBinaryTokenizer;
+import edu.uci.ics.hyracks.storage.am.invertedindex.tokenizers.IBinaryTokenizerFactory;
+import edu.uci.ics.hyracks.storage.common.IStorageManagerInterface;
+
+public class InvertedIndexSearchOperatorDescriptor extends AbstractInvertedIndexOperatorDescriptor {
+    private static final long serialVersionUID = 1L;
+
+    private final int queryField;
+    private final IBinaryTokenizerFactory queryTokenizerFactory;
+    private final IInvertedIndexSearchModifierFactory searchModifierFactory;
+
+    public InvertedIndexSearchOperatorDescriptor(JobSpecification spec,
+            int queryField, IStorageManagerInterface storageManager, IFileSplitProvider btreeFileSplitProvider,
+            IFileSplitProvider invListsFileSplitProvider, IIndexRegistryProvider<IIndex> indexRegistryProvider,
+            ITypeTraits[] tokenTypeTraits, IBinaryComparatorFactory[] tokenComparatorFactories,
+            ITypeTraits[] invListsTypeTraits, IBinaryComparatorFactory[] invListComparatorFactories,
+            IIndexDataflowHelperFactory btreeDataflowHelperFactory, IBinaryTokenizerFactory queryTokenizerFactory,
+            IInvertedIndexSearchModifierFactory searchModifierFactory, RecordDescriptor recDesc) {
+        super(spec, 1, 1, recDesc, storageManager, btreeFileSplitProvider, invListsFileSplitProvider,
+                indexRegistryProvider, tokenTypeTraits, tokenComparatorFactories, invListsTypeTraits,
+                invListComparatorFactories, btreeDataflowHelperFactory);
+        this.queryField = queryField;
+        this.queryTokenizerFactory = queryTokenizerFactory;
+        this.searchModifierFactory = searchModifierFactory;
+    }
+
+    @Override
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx,
+            IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) throws HyracksDataException {
+        IBinaryTokenizer tokenizer = queryTokenizerFactory.createTokenizer();
+        IInvertedIndexSearchModifier searchModifier = searchModifierFactory.createSearchModifier();
+        return new InvertedIndexSearchOperatorNodePushable(this, ctx, partition, queryField, searchModifier, tokenizer,
+                recordDescProvider);
+    }
+}
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/InvertedIndexSearchOperatorNodePushable.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/InvertedIndexSearchOperatorNodePushable.java
new file mode 100644
index 0000000..ceaff1e
--- /dev/null
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/InvertedIndexSearchOperatorNodePushable.java
@@ -0,0 +1,183 @@
+/*
+ * Copyright 2009-2010 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.invertedindex.dataflow;
+
+import java.io.DataOutput;
+import java.nio.ByteBuffer;
+
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+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.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.common.data.accessors.FrameTupleReference;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
+import edu.uci.ics.hyracks.dataflow.std.base.AbstractUnaryInputUnaryOutputOperatorNodePushable;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.TreeIndexDataflowHelper;
+import edu.uci.ics.hyracks.storage.am.invertedindex.api.IInvertedIndexResultCursor;
+import edu.uci.ics.hyracks.storage.am.invertedindex.api.IInvertedIndexSearchModifier;
+import edu.uci.ics.hyracks.storage.am.invertedindex.impls.InvertedIndex;
+import edu.uci.ics.hyracks.storage.am.invertedindex.impls.OccurrenceThresholdPanicException;
+import edu.uci.ics.hyracks.storage.am.invertedindex.impls.SearchResultCursor;
+import edu.uci.ics.hyracks.storage.am.invertedindex.impls.TOccurrenceSearcher;
+import edu.uci.ics.hyracks.storage.am.invertedindex.tokenizers.IBinaryTokenizer;
+
+public class InvertedIndexSearchOperatorNodePushable extends AbstractUnaryInputUnaryOutputOperatorNodePushable {
+    private final TreeIndexDataflowHelper btreeDataflowHelper;
+    private final InvertedIndexDataflowHelper invIndexDataflowHelper;
+    private final IHyracksTaskContext ctx;
+    private final int queryField;
+    private FrameTupleAccessor accessor;
+    private FrameTupleReference tuple;
+    private IRecordDescriptorProvider recordDescProvider;
+    private InvertedIndex invIndex;
+
+    private final IInvertedIndexSearchModifier searchModifier;
+    private final IBinaryTokenizer queryTokenizer;
+    private TOccurrenceSearcher searcher;
+    private IInvertedIndexResultCursor resultCursor;
+
+    private ByteBuffer writeBuffer;
+    private FrameTupleAppender appender;
+    private ArrayTupleBuilder tb;
+    private DataOutput dos;
+
+    private final AbstractInvertedIndexOperatorDescriptor opDesc;
+
+    public InvertedIndexSearchOperatorNodePushable(AbstractInvertedIndexOperatorDescriptor opDesc,
+            IHyracksTaskContext ctx, int partition, int queryField, IInvertedIndexSearchModifier searchModifier,
+            IBinaryTokenizer queryTokenizer, IRecordDescriptorProvider recordDescProvider) {
+        this.opDesc = opDesc;
+        btreeDataflowHelper = (TreeIndexDataflowHelper) opDesc.getIndexDataflowHelperFactory()
+                .createIndexDataflowHelper(opDesc, ctx, partition, false);
+        invIndexDataflowHelper = new InvertedIndexDataflowHelper(btreeDataflowHelper, opDesc, ctx, partition, false);
+        this.ctx = ctx;
+        this.queryField = queryField;
+        this.searchModifier = searchModifier;
+        this.queryTokenizer = queryTokenizer;
+        this.recordDescProvider = recordDescProvider;
+    }
+
+    @Override
+    public void open() throws HyracksDataException {
+        RecordDescriptor recDesc = recordDescProvider.getInputRecordDescriptor(opDesc.getOperatorId(), 0);
+        accessor = new FrameTupleAccessor(btreeDataflowHelper.getHyracksTaskContext().getFrameSize(), recDesc);
+        tuple = new FrameTupleReference();
+        // BTree.
+        try {
+            btreeDataflowHelper.init();
+        } catch (Exception e) {
+            // Cleanup in case of failure/
+            btreeDataflowHelper.deinit();
+            if (e instanceof HyracksDataException) {
+                throw (HyracksDataException) e;
+            } else {
+                throw new HyracksDataException(e);
+            }
+        }
+        // Inverted Index.
+        try {
+            invIndexDataflowHelper.init();
+            invIndex = (InvertedIndex) invIndexDataflowHelper.getIndex();
+        } catch (Exception e) {
+            // Cleanup in case of failure.
+            invIndexDataflowHelper.deinit();
+            if (e instanceof HyracksDataException) {
+                throw (HyracksDataException) e;
+            } else {
+                throw new HyracksDataException(e);
+            }
+        }
+
+        writeBuffer = btreeDataflowHelper.getHyracksTaskContext().allocateFrame();
+        tb = new ArrayTupleBuilder(opDesc.getInvListsTypeTraits().length);
+        dos = tb.getDataOutput();
+        appender = new FrameTupleAppender(btreeDataflowHelper.getHyracksTaskContext().getFrameSize());
+        appender.reset(writeBuffer, true);
+
+        searcher = new TOccurrenceSearcher(ctx, invIndex, queryTokenizer);
+        resultCursor = new SearchResultCursor(searcher.createResultFrameTupleAccessor(),
+                searcher.createResultTupleReference());
+
+        writer.open();
+    }
+
+    private void writeSearchResults() throws Exception {
+        while (resultCursor.hasNext()) {
+            resultCursor.next();
+            tb.reset();
+            ITupleReference invListElement = resultCursor.getTuple();
+            int invListFields = opDesc.getInvListsTypeTraits().length;
+            for (int i = 0; i < invListFields; i++) {
+                dos.write(invListElement.getFieldData(i), invListElement.getFieldStart(i),
+                        invListElement.getFieldLength(i));
+                tb.addFieldEndOffset();
+            }
+            if (!appender.append(tb.getFieldEndOffsets(), tb.getByteArray(), 0, tb.getSize())) {
+                FrameUtils.flushFrame(writeBuffer, writer);
+                appender.reset(writeBuffer, true);
+                if (!appender.append(tb.getFieldEndOffsets(), tb.getByteArray(), 0, tb.getSize())) {
+                    throw new IllegalStateException();
+                }
+            }
+        }
+    }
+
+    @Override
+    public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
+        accessor.reset(buffer);
+        int tupleCount = accessor.getTupleCount();
+        try {
+            for (int i = 0; i < tupleCount; i++) {
+                tuple.reset(accessor, i);
+                searcher.reset();
+                try {
+                    searcher.reset();
+                    searcher.search(resultCursor, tuple, queryField, searchModifier);
+                    writeSearchResults();
+                } catch (OccurrenceThresholdPanicException e) {
+                    // Ignore panic cases for now.
+                }
+            }
+        } catch (Exception e) {
+            throw new HyracksDataException(e);
+        }
+    }
+
+    @Override
+    public void fail() throws HyracksDataException {
+        writer.fail();
+    }
+
+    @Override
+    public void close() throws HyracksDataException {
+        try {
+            if (appender.getTupleCount() > 0) {
+                FrameUtils.flushFrame(writeBuffer, writer);
+            }
+            writer.close();
+        } finally {
+            try {
+                btreeDataflowHelper.deinit();
+            } finally {
+                invIndexDataflowHelper.deinit();
+            }
+        }
+    }
+}
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/FixedSizeElementInvertedListBuilder.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/FixedSizeElementInvertedListBuilder.java
index 03fc9a1..643c105 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/FixedSizeElementInvertedListBuilder.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/FixedSizeElementInvertedListBuilder.java
@@ -15,7 +15,7 @@
 
 package edu.uci.ics.hyracks.storage.am.invertedindex.impls;
 
-import edu.uci.ics.hyracks.api.dataflow.value.ITypeTrait;
+import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
 import edu.uci.ics.hyracks.storage.am.invertedindex.api.IInvertedListBuilder;
 
@@ -26,10 +26,10 @@
     private byte[] targetBuf;
     private int pos;
 
-    public FixedSizeElementInvertedListBuilder(ITypeTrait[] invListFields) {
+    public FixedSizeElementInvertedListBuilder(ITypeTraits[] invListFields) {
         int tmp = 0;
         for (int i = 0; i < invListFields.length; i++) {
-            tmp += invListFields[i].getStaticallyKnownDataLength();
+            tmp += invListFields[i].getFixedLength();
         }
         listElementSize = tmp;
     }
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/FixedSizeElementInvertedListCursor.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/FixedSizeElementInvertedListCursor.java
index f7ef56e..4158019 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/FixedSizeElementInvertedListCursor.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/FixedSizeElementInvertedListCursor.java
@@ -5,7 +5,7 @@
 import java.io.DataInputStream;
 
 import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
-import edu.uci.ics.hyracks.api.dataflow.value.ITypeTrait;
+import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 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.common.ophelpers.MultiComparator;
@@ -32,7 +32,7 @@
     private ICachedPage[] pages = new ICachedPage[10];
     private int[] elementIndexes = new int[10];
 
-    public FixedSizeElementInvertedListCursor(IBufferCache bufferCache, int fileId, ITypeTrait[] invListFields) {
+    public FixedSizeElementInvertedListCursor(IBufferCache bufferCache, int fileId, ITypeTraits[] invListFields) {
         this.bufferCache = bufferCache;
         this.fileId = fileId;
         this.currentElementIx = 0;
@@ -40,7 +40,7 @@
 
         int tmp = 0;
         for (int i = 0; i < invListFields.length; i++) {
-            tmp += invListFields[i].getStaticallyKnownDataLength();
+            tmp += invListFields[i].getFixedLength();
         }
         elementSize = tmp;
         this.currentOff = -elementSize;
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/FixedSizeFrameTupleAccessor.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/FixedSizeFrameTupleAccessor.java
index 9858eb0..cbedc45 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/FixedSizeFrameTupleAccessor.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/FixedSizeFrameTupleAccessor.java
@@ -19,29 +19,29 @@
 
 import edu.uci.ics.hyracks.api.comm.FrameHelper;
 import edu.uci.ics.hyracks.api.comm.IFrameTupleAccessor;
-import edu.uci.ics.hyracks.api.dataflow.value.ITypeTrait;
+import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 
 public class FixedSizeFrameTupleAccessor implements IFrameTupleAccessor {
 
     private final int frameSize;
     private ByteBuffer buffer;
 
-    private final ITypeTrait[] fields;
+    private final ITypeTraits[] fields;
     private final int[] fieldStartOffsets;
     private final int tupleSize;
 
-    public FixedSizeFrameTupleAccessor(int frameSize, ITypeTrait[] fields) {
+    public FixedSizeFrameTupleAccessor(int frameSize, ITypeTraits[] fields) {
         this.frameSize = frameSize;
         this.fields = fields;
         this.fieldStartOffsets = new int[fields.length];
         this.fieldStartOffsets[0] = 0;
         for (int i = 1; i < fields.length; i++) {
-            fieldStartOffsets[i] = fieldStartOffsets[i - 1] + fields[i - 1].getStaticallyKnownDataLength();
+            fieldStartOffsets[i] = fieldStartOffsets[i - 1] + fields[i - 1].getFixedLength();
         }
 
         int tmp = 0;
         for (int i = 0; i < fields.length; i++) {
-            tmp += fields[i].getStaticallyKnownDataLength();
+            tmp += fields[i].getFixedLength();
         }
         tupleSize = tmp;
     }
@@ -58,12 +58,12 @@
 
     @Override
     public int getFieldEndOffset(int tupleIndex, int fIdx) {
-        return getTupleStartOffset(tupleIndex) + fieldStartOffsets[fIdx] + fields[fIdx].getStaticallyKnownDataLength();
+        return getTupleStartOffset(tupleIndex) + fieldStartOffsets[fIdx] + fields[fIdx].getFixedLength();
     }
 
     @Override
     public int getFieldLength(int tupleIndex, int fIdx) {
-        return fields[fIdx].getStaticallyKnownDataLength();
+        return fields[fIdx].getFixedLength();
     }
 
     @Override
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/FixedSizeFrameTupleAppender.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/FixedSizeFrameTupleAppender.java
index edc2304..489ec2e 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/FixedSizeFrameTupleAppender.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/FixedSizeFrameTupleAppender.java
@@ -18,7 +18,7 @@
 import java.nio.ByteBuffer;
 
 import edu.uci.ics.hyracks.api.comm.FrameHelper;
-import edu.uci.ics.hyracks.api.dataflow.value.ITypeTrait;
+import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 
 public class FixedSizeFrameTupleAppender {
 
@@ -29,11 +29,11 @@
     private int tupleCount;
     private int tupleDataEndOffset;
 
-    public FixedSizeFrameTupleAppender(int frameSize, ITypeTrait[] fields) {
+    public FixedSizeFrameTupleAppender(int frameSize, ITypeTraits[] fields) {
         this.frameSize = frameSize;
         int tmp = 0;
         for (int i = 0; i < fields.length; i++) {
-            tmp += fields[i].getStaticallyKnownDataLength();
+            tmp += fields[i].getFixedLength();
         }
         tupleSize = tmp;
     }
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/FixedSizeTupleReference.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/FixedSizeTupleReference.java
index 248b81e..0656d69 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/FixedSizeTupleReference.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/FixedSizeTupleReference.java
@@ -15,22 +15,22 @@
 
 package edu.uci.ics.hyracks.storage.am.invertedindex.impls;
 
-import edu.uci.ics.hyracks.api.dataflow.value.ITypeTrait;
+import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
 
 public class FixedSizeTupleReference implements ITupleReference {
 
-    private final ITypeTrait[] typeTraits;
+    private final ITypeTraits[] typeTraits;
     private final int[] fieldStartOffsets;
     private byte[] data;
     private int startOff;
 
-    public FixedSizeTupleReference(ITypeTrait[] typeTraits) {
+    public FixedSizeTupleReference(ITypeTraits[] typeTraits) {
         this.typeTraits = typeTraits;
         this.fieldStartOffsets = new int[typeTraits.length];
         this.fieldStartOffsets[0] = 0;
         for (int i = 1; i < typeTraits.length; i++) {
-            fieldStartOffsets[i] = fieldStartOffsets[i - 1] + typeTraits[i - 1].getStaticallyKnownDataLength();
+            fieldStartOffsets[i] = fieldStartOffsets[i - 1] + typeTraits[i - 1].getFixedLength();
         }
     }
 
@@ -51,7 +51,7 @@
 
     @Override
     public int getFieldLength(int fIdx) {
-        return typeTraits[fIdx].getStaticallyKnownDataLength();
+        return typeTraits[fIdx].getFixedLength();
     }
 
     @Override
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/InvertedIndex.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/InvertedIndex.java
index 9eab110..986e57b 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/InvertedIndex.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/InvertedIndex.java
@@ -18,6 +18,7 @@
 import java.nio.ByteBuffer;
 
 import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
+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.dataflow.common.comm.io.ArrayTupleBuilder;
@@ -28,10 +29,13 @@
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
 import edu.uci.ics.hyracks.dataflow.common.data.marshalling.IntegerSerializerDeserializer;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
-import edu.uci.ics.hyracks.storage.am.btree.impls.BTreeOpContext;
 import edu.uci.ics.hyracks.storage.am.btree.impls.RangePredicate;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexBulkLoadContext;
+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.PageAllocationException;
+import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
+import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndex;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
 import edu.uci.ics.hyracks.storage.am.invertedindex.api.IInvertedListBuilder;
 import edu.uci.ics.hyracks.storage.am.invertedindex.api.IInvertedListCursor;
@@ -47,34 +51,41 @@
  * implemented features: updates (insert/update/delete) Limitations: a query
  * cannot exceed the size of a Hyracks frame
  */
-public class InvertedIndex {
+public class InvertedIndex implements IIndex {
 
     private BTree btree;
     private int rootPageId = 0;
     private IBufferCache bufferCache;
     private int fileId;
+    private final ITypeTraits[] invListTypeTraits;
     private final MultiComparator invListCmp;
     private final int numTokenFields;
     private final int numInvListKeys;
 
-    public InvertedIndex(IBufferCache bufferCache, BTree btree, MultiComparator invListCmp) {
+    public InvertedIndex(IBufferCache bufferCache, BTree btree, ITypeTraits[] invListTypeTraits, MultiComparator invListCmp) {
         this.bufferCache = bufferCache;
         this.btree = btree;
         this.invListCmp = invListCmp;
+        this.invListTypeTraits = invListTypeTraits;
         this.numTokenFields = btree.getMultiComparator().getKeyFieldCount();
         this.numInvListKeys = invListCmp.getKeyFieldCount();
     }
 
+    @Override
     public void open(int fileId) {
         this.fileId = fileId;
     }
 
+    @Override
+    public void create(int indexFileId) throws HyracksDataException {
+    }
+    
     public void close() {
         this.fileId = -1;
     }
 
     public BulkLoadContext beginBulkLoad(IInvertedListBuilder invListBuilder, int hyracksFrameSize,
-            float btreeFillFactor) throws HyracksDataException {
+            float btreeFillFactor) throws HyracksDataException, TreeIndexException, PageAllocationException {
         BulkLoadContext ctx = new BulkLoadContext(invListBuilder, hyracksFrameSize, btreeFillFactor);
         ctx.init(rootPageId, fileId);
         return ctx;
@@ -86,7 +97,7 @@
     // the next invListCmp.getKeyFieldCount() fields in tuple are keys of the
     // inverted list (e.g., primary key)
     // key fields of inverted list are fixed size
-    public void bulkLoadAddTuple(BulkLoadContext ctx, ITupleReference tuple) throws HyracksDataException {
+    public void bulkLoadAddTuple(BulkLoadContext ctx, ITupleReference tuple) throws HyracksDataException, PageAllocationException {
 
         // first inverted list, copy token to baaos and start new list
         if (ctx.currentInvListTokenBaaos.size() == 0) {
@@ -147,9 +158,9 @@
         }
     }
 
-    public boolean openCursor(ITreeIndexCursor btreeCursor, RangePredicate btreePred, BTreeOpContext btreeOpCtx,
+    public boolean openCursor(ITreeIndexCursor btreeCursor, RangePredicate btreePred, ITreeIndexAccessor btreeAccessor,
             IInvertedListCursor invListCursor) throws Exception {
-        btree.search(btreeCursor, btreePred, btreeOpCtx);
+    	btreeAccessor.search(btreeCursor, btreePred);
 
         boolean ret = false;
         if (btreeCursor.hasNext()) {
@@ -179,7 +190,7 @@
         return ret;
     }
 
-    public void createAndInsertBTreeTuple(BulkLoadContext ctx) throws HyracksDataException {
+    public void createAndInsertBTreeTuple(BulkLoadContext ctx) throws HyracksDataException, PageAllocationException {
         // build tuple
         ctx.btreeTupleBuilder.reset();
         ctx.btreeTupleBuilder.addField(ctx.currentInvListTokenBaaos.getByteArray(), 0,
@@ -197,10 +208,10 @@
         // reset tuple reference
         ctx.btreeFrameTupleReference.reset(ctx.btreeFrameTupleAccessor, 0);
 
-        btree.bulkLoadAddTuple(ctx.btreeBulkLoadCtx, ctx.btreeFrameTupleReference);
+        btree.bulkLoadAddTuple(ctx.btreeFrameTupleReference, ctx.btreeBulkLoadCtx);
     }
 
-    public void endBulkLoad(BulkLoadContext ctx) throws HyracksDataException {
+    public void endBulkLoad(BulkLoadContext ctx) throws HyracksDataException, PageAllocationException {
         // create entry in btree for last inverted list
         createAndInsertBTreeTuple(ctx);
         btree.endBulkLoad(ctx.btreeBulkLoadCtx);
@@ -218,6 +229,10 @@
     public MultiComparator getInvListElementCmp() {
         return invListCmp;
     }
+    
+    public ITypeTraits[] getTypeTraits() {
+        return invListTypeTraits;
+    }
 
     public BTree getBTree() {
         return btree;
@@ -235,8 +250,7 @@
         private int currentInvListStartPageId;
         private int currentInvListStartOffset;
         private final ByteArrayAccessibleOutputStream currentInvListTokenBaaos = new ByteArrayAccessibleOutputStream();
-        private final FixedSizeTupleReference currentInvListToken = new FixedSizeTupleReference(
-                invListCmp.getTypeTraits());
+        private final FixedSizeTupleReference currentInvListToken = new FixedSizeTupleReference(invListTypeTraits);
 
         private int currentPageId;
         private ICachedPage currentPage;
@@ -247,7 +261,7 @@
             this.invListBuilder = invListBuilder;
             this.tokenCmp = btree.getMultiComparator();
             this.btreeTupleBuffer = ByteBuffer.allocate(hyracksFrameSize);
-            this.btreeTupleBuilder = new ArrayTupleBuilder(tokenCmp.getFieldCount());
+            this.btreeTupleBuilder = new ArrayTupleBuilder(btree.getFieldCount());
             this.btreeTupleAppender = new FrameTupleAppender(hyracksFrameSize);
             // TODO: serde never used, only need correct number of fields
             // tuple contains (token, start page, end page, start offset, num
@@ -260,10 +274,8 @@
             this.btreeFillFactor = btreeFillFactor;
         }
 
-        public void init(int startPageId, int fileId) throws HyracksDataException {
-            btreeBulkLoadCtx = btree.beginBulkLoad(BTree.DEFAULT_FILL_FACTOR,
-                    btree.getLeafFrameFactory().createFrame(), btree.getInteriorFrameFactory().createFrame(), btree
-                            .getFreePageManager().getMetaDataFrameFactory().createFrame());
+        public void init(int startPageId, int fileId) throws HyracksDataException, TreeIndexException, PageAllocationException {
+            btreeBulkLoadCtx = btree.beginBulkLoad(BTree.DEFAULT_FILL_FACTOR);
             currentPageId = startPageId;
             currentPage = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, currentPageId), true);
             currentPage.acquireWriteLatch();
@@ -285,5 +297,5 @@
             currentPage = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, currentPageId), true);
             currentPage.acquireWriteLatch();
         }
-    };
+    }
 }
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/TOccurrenceSearcher.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/TOccurrenceSearcher.java
index d1fba3b..b24d416 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/TOccurrenceSearcher.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/TOccurrenceSearcher.java
@@ -22,12 +22,12 @@
 import java.util.List;
 
 import edu.uci.ics.hyracks.api.comm.IFrameTupleAccessor;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
-import edu.uci.ics.hyracks.api.dataflow.value.ITypeTrait;
+import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
-import edu.uci.ics.hyracks.api.dataflow.value.TypeTrait;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.data.std.primitive.IntegerPointable;
 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;
@@ -36,12 +36,11 @@
 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.storage.am.btree.api.IBTreeLeafFrame;
-import edu.uci.ics.hyracks.storage.am.btree.impls.BTreeOpContext;
 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.ITreeIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexCursor;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrame;
-import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOp;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
 import edu.uci.ics.hyracks.storage.am.invertedindex.api.IInvertedIndexResultCursor;
 import edu.uci.ics.hyracks.storage.am.invertedindex.api.IInvertedIndexSearchModifier;
@@ -52,7 +51,7 @@
 
 public class TOccurrenceSearcher implements IInvertedIndexSearcher {
 
-    protected final IHyracksStageletContext ctx;
+    protected final IHyracksTaskContext ctx;
     protected final FixedSizeFrameTupleAppender resultFrameTupleApp;
     protected final FixedSizeFrameTupleAccessor resultFrameTupleAcc;
     protected final FixedSizeTupleReference resultTuple;
@@ -69,25 +68,25 @@
     protected final ITreeIndexCursor btreeCursor;
     protected final FrameTupleReference searchKey = new FrameTupleReference();
     protected final RangePredicate btreePred = new RangePredicate(true, null, null, true, true, null, null);
-    protected final BTreeOpContext btreeOpCtx;
+    protected final ITreeIndexAccessor btreeAccessor;
 
     protected RecordDescriptor queryTokenRecDesc = new RecordDescriptor(
             new ISerializerDeserializer[] { UTF8StringSerializerDeserializer.INSTANCE });
-    protected ArrayTupleBuilder queryTokenBuilder = new ArrayTupleBuilder(queryTokenRecDesc.getFields().length);
+    protected ArrayTupleBuilder queryTokenBuilder = new ArrayTupleBuilder(queryTokenRecDesc.getFieldCount());
     protected DataOutput queryTokenDos = queryTokenBuilder.getDataOutput();
     protected FrameTupleAppender queryTokenAppender;
     protected ByteBuffer queryTokenFrame;
 
     protected final InvertedIndex invIndex;
     protected final IBinaryTokenizer queryTokenizer;
-    protected final ITypeTrait[] invListFieldsWithCount;
+    protected final ITypeTraits[] invListFieldsWithCount;
     protected int occurrenceThreshold;
 
     protected final int cursorCacheSize = 10;
     protected List<IInvertedListCursor> invListCursorCache = new ArrayList<IInvertedListCursor>(cursorCacheSize);
     protected List<IInvertedListCursor> invListCursors = new ArrayList<IInvertedListCursor>(cursorCacheSize);
 
-    public TOccurrenceSearcher(IHyracksStageletContext ctx, InvertedIndex invIndex, IBinaryTokenizer queryTokenizer) {
+    public TOccurrenceSearcher(IHyracksTaskContext ctx, InvertedIndex invIndex, IBinaryTokenizer queryTokenizer) {
         this.ctx = ctx;
         this.invIndex = invIndex;
         this.queryTokenizer = queryTokenizer;
@@ -95,20 +94,18 @@
         leafFrame = invIndex.getBTree().getLeafFrameFactory().createFrame();
         interiorFrame = invIndex.getBTree().getInteriorFrameFactory().createFrame();
 
-        btreeCursor = new BTreeRangeSearchCursor((IBTreeLeafFrame) leafFrame);
-        ITypeTrait[] invListFields = invIndex.getInvListElementCmp().getTypeTraits();
-        invListFieldsWithCount = new TypeTrait[invListFields.length + 1];
+        btreeCursor = new BTreeRangeSearchCursor((IBTreeLeafFrame) leafFrame, false);
+        ITypeTraits[] invListFields = invIndex.getTypeTraits();
+        invListFieldsWithCount = new ITypeTraits[invListFields.length + 1];
         int tmp = 0;
         for (int i = 0; i < invListFields.length; i++) {
             invListFieldsWithCount[i] = invListFields[i];
-            tmp += invListFields[i].getStaticallyKnownDataLength();
+            tmp += invListFields[i].getFixedLength();
         }
         // using an integer for counting occurrences
-        invListFieldsWithCount[invListFields.length] = new TypeTrait(4);
+        invListFieldsWithCount[invListFields.length] = IntegerPointable.TYPE_TRAITS;
         invListKeyLength = tmp;
 
-        btreeOpCtx = invIndex.getBTree().createOpContext(IndexOp.SEARCH, leafFrame, interiorFrame, null);
-
         resultFrameTupleApp = new FixedSizeFrameTupleAppender(ctx.getFrameSize(), invListFieldsWithCount);
         resultFrameTupleAcc = new FixedSizeFrameTupleAccessor(ctx.getFrameSize(), invListFieldsWithCount);
         resultTuple = new FixedSizeTupleReference(invListFieldsWithCount);
@@ -124,12 +121,13 @@
         // pre-create cursor objects
         for (int i = 0; i < cursorCacheSize; i++) {
             invListCursorCache.add(new FixedSizeElementInvertedListCursor(invIndex.getBufferCache(), invIndex
-                    .getInvListsFileId(), invIndex.getInvListElementCmp().getTypeTraits()));
+                    .getInvListsFileId(), invIndex.getTypeTraits()));
         }
 
         queryTokenAppender = new FrameTupleAppender(ctx.getFrameSize());
         queryTokenFrame = ctx.allocateFrame();
 
+        btreeAccessor = invIndex.getBTree().createAccessor();
         currentNumResults = 0;
     }
 
@@ -143,12 +141,12 @@
         currentNumResults = 0;
     }
 
-    public void search(IInvertedIndexResultCursor resultCursor, ITupleReference queryTuple, int queryFieldIndex,
+    public void search(IInvertedIndexResultCursor resultCursor, ITupleReference queryTuple, int queryField,
             IInvertedIndexSearchModifier searchModifier) throws Exception {
 
         queryTokenAppender.reset(queryTokenFrame, true);
-        queryTokenizer.reset(queryTuple.getFieldData(queryFieldIndex), queryTuple.getFieldStart(queryFieldIndex),
-                queryTuple.getFieldLength(queryFieldIndex));
+        queryTokenizer.reset(queryTuple.getFieldData(queryField), queryTuple.getFieldStart(queryField),
+                queryTuple.getFieldLength(queryField));
 
         while (queryTokenizer.hasNext()) {
             queryTokenizer.next();
@@ -174,14 +172,14 @@
             int diff = numQueryTokens - invListCursorCache.size();
             for (int i = 0; i < diff; i++) {
                 invListCursorCache.add(new FixedSizeElementInvertedListCursor(invIndex.getBufferCache(), invIndex
-                        .getInvListsFileId(), invIndex.getInvListElementCmp().getTypeTraits()));
+                        .getInvListsFileId(), invIndex.getTypeTraits()));
             }
         }
 
         invListCursors.clear();
         for (int i = 0; i < numQueryTokens; i++) {
             searchKey.reset(queryTokenAccessor, i);
-            invIndex.openCursor(btreeCursor, btreePred, btreeOpCtx, invListCursorCache.get(i));
+            invIndex.openCursor(btreeCursor, btreePred, btreeAccessor, invListCursorCache.get(i));
             invListCursors.add(invListCursorCache.get(i));
         }
 
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/TOccurrenceSearcherSuffixProbeOnly.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/TOccurrenceSearcherSuffixProbeOnly.java
index 30d67f0..0f5439b 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/TOccurrenceSearcherSuffixProbeOnly.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/TOccurrenceSearcherSuffixProbeOnly.java
@@ -19,7 +19,7 @@
 import java.nio.ByteBuffer;
 import java.util.List;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.dataflow.common.data.marshalling.IntegerSerializerDeserializer;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
 import edu.uci.ics.hyracks.storage.am.invertedindex.api.IInvertedListCursor;
@@ -27,7 +27,7 @@
 
 public class TOccurrenceSearcherSuffixProbeOnly extends TOccurrenceSearcher {
 
-    public TOccurrenceSearcherSuffixProbeOnly(IHyracksStageletContext ctx, InvertedIndex invIndex,
+    public TOccurrenceSearcherSuffixProbeOnly(IHyracksTaskContext ctx, InvertedIndex invIndex,
             IBinaryTokenizer queryTokenizer) {
         super(ctx, invIndex, queryTokenizer);
     }
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/TOccurrenceSearcherSuffixScanOnly.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/TOccurrenceSearcherSuffixScanOnly.java
index f8bc1ab..b997dc9 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/TOccurrenceSearcherSuffixScanOnly.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/TOccurrenceSearcherSuffixScanOnly.java
@@ -19,7 +19,7 @@
 import java.nio.ByteBuffer;
 import java.util.List;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
 import edu.uci.ics.hyracks.dataflow.common.data.marshalling.IntegerSerializerDeserializer;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
@@ -28,7 +28,7 @@
 
 public class TOccurrenceSearcherSuffixScanOnly extends TOccurrenceSearcher {
 
-    public TOccurrenceSearcherSuffixScanOnly(IHyracksStageletContext ctx, InvertedIndex invIndex,
+    public TOccurrenceSearcherSuffixScanOnly(IHyracksTaskContext ctx, InvertedIndex invIndex,
             IBinaryTokenizer queryTokenizer) {
         super(ctx, invIndex, queryTokenizer);
     }
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/searchmodifiers/ConjunctiveSearchModifierFactory.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/searchmodifiers/ConjunctiveSearchModifierFactory.java
new file mode 100644
index 0000000..0db6008
--- /dev/null
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/searchmodifiers/ConjunctiveSearchModifierFactory.java
@@ -0,0 +1,28 @@
+/*
+ * Copyright 2009-2010 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.invertedindex.searchmodifiers;
+
+import edu.uci.ics.hyracks.storage.am.invertedindex.api.IInvertedIndexSearchModifier;
+import edu.uci.ics.hyracks.storage.am.invertedindex.api.IInvertedIndexSearchModifierFactory;
+
+public class ConjunctiveSearchModifierFactory implements IInvertedIndexSearchModifierFactory {
+    private static final long serialVersionUID = 1L;
+
+    @Override
+    public IInvertedIndexSearchModifier createSearchModifier() {
+        return new ConjunctiveSearchModifier();
+    }
+}
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/searchmodifiers/EditDistanceSearchModifierFactory.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/searchmodifiers/EditDistanceSearchModifierFactory.java
new file mode 100644
index 0000000..128d9db
--- /dev/null
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/searchmodifiers/EditDistanceSearchModifierFactory.java
@@ -0,0 +1,37 @@
+/*
+ * Copyright 2009-2010 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.invertedindex.searchmodifiers;
+
+import edu.uci.ics.hyracks.storage.am.invertedindex.api.IInvertedIndexSearchModifier;
+import edu.uci.ics.hyracks.storage.am.invertedindex.api.IInvertedIndexSearchModifierFactory;
+
+public class EditDistanceSearchModifierFactory implements IInvertedIndexSearchModifierFactory {
+
+    private static final long serialVersionUID = 1L;
+
+    private final int gramLength;
+    private final int edThresh;
+    
+    public EditDistanceSearchModifierFactory(int gramLength, int edThresh) {
+        this.gramLength = gramLength;
+        this.edThresh = edThresh;
+    }
+    
+    @Override
+    public IInvertedIndexSearchModifier createSearchModifier() {
+        return new EditDistanceSearchModifier(gramLength, edThresh);
+    }
+}
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/searchmodifiers/JaccardSearchModifierFactory.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/searchmodifiers/JaccardSearchModifierFactory.java
new file mode 100644
index 0000000..bd27c03
--- /dev/null
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/searchmodifiers/JaccardSearchModifierFactory.java
@@ -0,0 +1,35 @@
+/*
+ * Copyright 2009-2010 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.invertedindex.searchmodifiers;
+
+import edu.uci.ics.hyracks.storage.am.invertedindex.api.IInvertedIndexSearchModifier;
+import edu.uci.ics.hyracks.storage.am.invertedindex.api.IInvertedIndexSearchModifierFactory;
+
+public class JaccardSearchModifierFactory implements IInvertedIndexSearchModifierFactory {
+
+    private static final long serialVersionUID = 1L;
+
+    private final float jaccThresh;
+
+    public JaccardSearchModifierFactory(float jaccThresh) {
+        this.jaccThresh = jaccThresh;
+    }
+
+    @Override
+    public IInvertedIndexSearchModifier createSearchModifier() {
+        return new JaccardSearchModifier(jaccThresh);
+    }
+}
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/AbstractUTF8StringBinaryTokenizer.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/AbstractUTF8StringBinaryTokenizer.java
index 02142dc..be6bfb0 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/AbstractUTF8StringBinaryTokenizer.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/AbstractUTF8StringBinaryTokenizer.java
@@ -19,7 +19,7 @@
 
 package edu.uci.ics.hyracks.storage.am.invertedindex.tokenizers;
 
-import edu.uci.ics.hyracks.dataflow.common.data.util.StringUtils;
+import edu.uci.ics.hyracks.data.std.primitive.UTF8StringPointable;
 
 public abstract class AbstractUTF8StringBinaryTokenizer implements IBinaryTokenizer {
 
@@ -63,7 +63,7 @@
         if (sourceHasTypeTag) {
             index++; // skip type tag
         }
-        utf8Length = StringUtils.getUTFLen(data, index);
+        utf8Length = UTF8StringPointable.getUTFLen(data, index);
         index += 2; // skip utf8 length indicator
         this.data = data;
         this.length = length + start;
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/AbstractUTF8Token.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/AbstractUTF8Token.java
index 0e9038a..65afa65 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/AbstractUTF8Token.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/AbstractUTF8Token.java
@@ -16,13 +16,12 @@
  * 
  * Author: Alexander Behm <abehm (at) ics.uci.edu>
  */
-
 package edu.uci.ics.hyracks.storage.am.invertedindex.tokenizers;
 
 import java.io.DataOutput;
 import java.io.IOException;
 
-import edu.uci.ics.hyracks.dataflow.common.data.util.StringUtils;
+import edu.uci.ics.hyracks.data.std.primitive.UTF8StringPointable;
 
 public abstract class AbstractUTF8Token implements IToken {
     public static final int GOLDEN_RATIO_32 = 0x09e3779b9;
@@ -59,9 +58,9 @@
         int lowerCaseUTF8Len = 0;
         int pos = start;
         for (int i = 0; i < size; i++) {
-            char c = Character.toLowerCase(StringUtils.charAt(data, pos));
-            lowerCaseUTF8Len += StringUtils.getModifiedUTF8Len(c);
-            pos += StringUtils.charSize(data, pos);
+            char c = Character.toLowerCase(UTF8StringPointable.charAt(data, pos));
+            lowerCaseUTF8Len += UTF8StringPointable.getModifiedUTF8Len(c);
+            pos += UTF8StringPointable.charSize(data, pos);
         }
         return lowerCaseUTF8Len;
     }
@@ -102,4 +101,4 @@
         handleCountTypeTag(dos);
         dos.writeInt(tokenCount);
     }
-}
+}
\ No newline at end of file
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/AbstractUTF8TokenFactory.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/AbstractUTF8TokenFactory.java
index b883c9a..3b0b82d 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/AbstractUTF8TokenFactory.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/AbstractUTF8TokenFactory.java
@@ -20,17 +20,17 @@
 package edu.uci.ics.hyracks.storage.am.invertedindex.tokenizers;
 
 public abstract class AbstractUTF8TokenFactory implements ITokenFactory {
-    private static final long serialVersionUID = 1L;
-    protected final byte tokenTypeTag;
-    protected final byte countTypeTag;
+	private static final long serialVersionUID = 1L;
+	protected final byte tokenTypeTag;
+	protected final byte countTypeTag;
 
-    public AbstractUTF8TokenFactory() {
-        tokenTypeTag = -1;
-        countTypeTag = -1;
-    }
+	public AbstractUTF8TokenFactory() {
+		tokenTypeTag = -1;
+		countTypeTag = -1;
+	}
 
-    public AbstractUTF8TokenFactory(byte tokenTypeTag, byte countTypeTag) {
-        this.tokenTypeTag = tokenTypeTag;
-        this.countTypeTag = countTypeTag;
-    }
+	public AbstractUTF8TokenFactory(byte tokenTypeTag, byte countTypeTag) {
+		this.tokenTypeTag = tokenTypeTag;
+		this.countTypeTag = countTypeTag;
+	}
 }
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/DelimitedUTF8StringBinaryTokenizer.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/DelimitedUTF8StringBinaryTokenizer.java
index 8f49c74..9dacde6 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/DelimitedUTF8StringBinaryTokenizer.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/DelimitedUTF8StringBinaryTokenizer.java
@@ -19,7 +19,7 @@
 
 package edu.uci.ics.hyracks.storage.am.invertedindex.tokenizers;
 
-import edu.uci.ics.hyracks.dataflow.common.data.util.StringUtils;
+import edu.uci.ics.hyracks.data.std.primitive.UTF8StringPointable;
 
 public class DelimitedUTF8StringBinaryTokenizer extends AbstractUTF8StringBinaryTokenizer {
 
@@ -31,8 +31,8 @@
     @Override
     public boolean hasNext() {
         // skip delimiters
-        while (index < length && isSeparator(StringUtils.charAt(data, index))) {
-            index += StringUtils.charSize(data, index);
+        while (index < length && isSeparator(UTF8StringPointable.charAt(data, index))) {
+            index += UTF8StringPointable.charSize(data, index);
         }
         return index < length;
     }
@@ -45,8 +45,8 @@
     public void next() {
         tokenLength = 0;
         int currentTokenStart = index;
-        while (index < length && !isSeparator(StringUtils.charAt(data, index))) {
-            index += StringUtils.charSize(data, index);
+        while (index < length && !isSeparator(UTF8StringPointable.charAt(data, index))) {
+            index += UTF8StringPointable.charSize(data, index);
             tokenLength++;
         }
         int tokenCount = 1;
@@ -60,11 +60,12 @@
                     int currLength = 0;
                     while (currLength < tokenLength) {
                         // case insensitive comparison
-                        if (Character.toLowerCase(StringUtils.charAt(data, currentTokenStart + offset)) != Character.toLowerCase(StringUtils.charAt(data, tokenStart + offset))) {
+                        if (Character.toLowerCase(UTF8StringPointable.charAt(data, currentTokenStart + offset)) != Character
+                                .toLowerCase(UTF8StringPointable.charAt(data, tokenStart + offset))) {
                             tokenCount--;
                             break;
                         }
-                        offset += StringUtils.charSize(data, currentTokenStart + offset);
+                        offset += UTF8StringPointable.charSize(data, currentTokenStart + offset);
                         currLength++;
                     }
                 }
@@ -77,4 +78,4 @@
         // set token
         token.reset(data, currentTokenStart, index, tokenLength, tokenCount);
     }
-}
+}
\ No newline at end of file
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/DelimitedUTF8StringBinaryTokenizerFactory.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/DelimitedUTF8StringBinaryTokenizerFactory.java
index 894501d..4a350b3 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/DelimitedUTF8StringBinaryTokenizerFactory.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/DelimitedUTF8StringBinaryTokenizerFactory.java
@@ -19,22 +19,24 @@
 
 package edu.uci.ics.hyracks.storage.am.invertedindex.tokenizers;
 
-public class DelimitedUTF8StringBinaryTokenizerFactory implements IBinaryTokenizerFactory {
+public class DelimitedUTF8StringBinaryTokenizerFactory implements
+		IBinaryTokenizerFactory {
 
-    private static final long serialVersionUID = 1L;
-    private final boolean ignoreTokenCount;
-    private final boolean sourceHasTypeTag;
-    private final ITokenFactory tokenFactory;
+	private static final long serialVersionUID = 1L;
+	private final boolean ignoreTokenCount;
+	private final boolean sourceHasTypeTag;
+	private final ITokenFactory tokenFactory;
 
-    public DelimitedUTF8StringBinaryTokenizerFactory(boolean ignoreTokenCount, boolean sourceHasTypeTag,
-            ITokenFactory tokenFactory) {
-        this.ignoreTokenCount = ignoreTokenCount;
-        this.sourceHasTypeTag = sourceHasTypeTag;
-        this.tokenFactory = tokenFactory;
-    }
+	public DelimitedUTF8StringBinaryTokenizerFactory(boolean ignoreTokenCount,
+			boolean sourceHasTypeTag, ITokenFactory tokenFactory) {
+		this.ignoreTokenCount = ignoreTokenCount;
+		this.sourceHasTypeTag = sourceHasTypeTag;
+		this.tokenFactory = tokenFactory;
+	}
 
-    @Override
-    public IBinaryTokenizer createTokenizer() {
-        return new DelimitedUTF8StringBinaryTokenizer(ignoreTokenCount, sourceHasTypeTag, tokenFactory);
-    }
+	@Override
+	public IBinaryTokenizer createTokenizer() {
+		return new DelimitedUTF8StringBinaryTokenizer(ignoreTokenCount,
+				sourceHasTypeTag, tokenFactory);
+	}
 }
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/HashedUTF8NGramToken.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/HashedUTF8NGramToken.java
index 43f89c7..b7bb828 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/HashedUTF8NGramToken.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/HashedUTF8NGramToken.java
@@ -22,7 +22,7 @@
 import java.io.DataOutput;
 import java.io.IOException;
 
-import edu.uci.ics.hyracks.dataflow.common.data.util.StringUtils;
+import edu.uci.ics.hyracks.data.std.primitive.UTF8StringPointable;
 
 public class HashedUTF8NGramToken extends UTF8NGramToken {
     public HashedUTF8NGramToken(byte tokenTypeTag, byte countTypeTag) {
@@ -45,9 +45,9 @@
         int numRegGrams = tokenLength - numPreChars - numPostChars;
         int pos = start;
         for (int i = 0; i < numRegGrams; i++) {
-            hash ^= Character.toLowerCase(StringUtils.charAt(data, pos));
+            hash ^= Character.toLowerCase(UTF8StringPointable.charAt(data, pos));
             hash *= GOLDEN_RATIO_32;
-            pos += StringUtils.charSize(data, pos);
+            pos += UTF8StringPointable.charSize(data, pos);
         }
 
         // post chars
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/HashedUTF8NGramTokenFactory.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/HashedUTF8NGramTokenFactory.java
index f04594a..4a87793 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/HashedUTF8NGramTokenFactory.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/HashedUTF8NGramTokenFactory.java
@@ -21,18 +21,18 @@
 
 public class HashedUTF8NGramTokenFactory extends AbstractUTF8TokenFactory {
 
-    private static final long serialVersionUID = 1L;
+	private static final long serialVersionUID = 1L;
 
-    public HashedUTF8NGramTokenFactory() {
-        super();
-    }
+	public HashedUTF8NGramTokenFactory() {
+		super();
+	}
 
-    public HashedUTF8NGramTokenFactory(byte tokenTypeTag, byte countTypeTag) {
-        super(tokenTypeTag, countTypeTag);
-    }
+	public HashedUTF8NGramTokenFactory(byte tokenTypeTag, byte countTypeTag) {
+		super(tokenTypeTag, countTypeTag);
+	}
 
-    @Override
-    public IToken createToken() {
-        return new HashedUTF8NGramToken(tokenTypeTag, countTypeTag);
-    }
+	@Override
+	public IToken createToken() {
+		return new HashedUTF8NGramToken(tokenTypeTag, countTypeTag);
+	}
 }
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/HashedUTF8WordToken.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/HashedUTF8WordToken.java
index 747b65d..42ed053 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/HashedUTF8WordToken.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/HashedUTF8WordToken.java
@@ -22,7 +22,7 @@
 import java.io.DataOutput;
 import java.io.IOException;
 
-import edu.uci.ics.hyracks.dataflow.common.data.util.StringUtils;
+import edu.uci.ics.hyracks.data.std.primitive.UTF8StringPointable;
 
 public class HashedUTF8WordToken extends UTF8WordToken {
 
@@ -46,10 +46,11 @@
         }
         int offset = 0;
         for (int i = 0; i < tokenLength; i++) {
-            if (StringUtils.charAt(t.getData(), t.getStart() + offset) != StringUtils.charAt(data, start + offset)) {
+            if (UTF8StringPointable.charAt(t.getData(), t.getStart() + offset) != UTF8StringPointable.charAt(data,
+                    start + offset)) {
                 return false;
             }
-            offset += StringUtils.charSize(data, start + offset);
+            offset += UTF8StringPointable.charSize(data, start + offset);
         }
         return true;
     }
@@ -67,9 +68,9 @@
         int pos = start;
         hash = GOLDEN_RATIO_32;
         for (int i = 0; i < tokenLength; i++) {
-            hash ^= Character.toLowerCase(StringUtils.charAt(data, pos));
+            hash ^= Character.toLowerCase(UTF8StringPointable.charAt(data, pos));
             hash *= GOLDEN_RATIO_32;
-            pos += StringUtils.charSize(data, pos);
+            pos += UTF8StringPointable.charSize(data, pos);
         }
         hash += tokenCount;
     }
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/HashedUTF8WordTokenFactory.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/HashedUTF8WordTokenFactory.java
index e8bbde8..318f041 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/HashedUTF8WordTokenFactory.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/HashedUTF8WordTokenFactory.java
@@ -21,18 +21,18 @@
 
 public class HashedUTF8WordTokenFactory extends AbstractUTF8TokenFactory {
 
-    private static final long serialVersionUID = 1L;
+	private static final long serialVersionUID = 1L;
 
-    public HashedUTF8WordTokenFactory() {
-        super();
-    }
+	public HashedUTF8WordTokenFactory() {
+		super();
+	}
 
-    public HashedUTF8WordTokenFactory(byte tokenTypeTag, byte countTypeTag) {
-        super(tokenTypeTag, countTypeTag);
-    }
+	public HashedUTF8WordTokenFactory(byte tokenTypeTag, byte countTypeTag) {
+		super(tokenTypeTag, countTypeTag);
+	}
 
-    @Override
-    public IToken createToken() {
-        return new HashedUTF8WordToken(tokenTypeTag, countTypeTag);
-    }
+	@Override
+	public IToken createToken() {
+		return new HashedUTF8WordToken(tokenTypeTag, countTypeTag);
+	}
 }
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/IBinaryTokenizer.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/IBinaryTokenizer.java
index c9087d7..05c6d0b 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/IBinaryTokenizer.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/IBinaryTokenizer.java
@@ -20,11 +20,11 @@
 package edu.uci.ics.hyracks.storage.am.invertedindex.tokenizers;
 
 public interface IBinaryTokenizer {
-    public IToken getToken();
+	public IToken getToken();
 
-    public boolean hasNext();
+	public boolean hasNext();
 
-    public void next();
+	public void next();
 
-    public void reset(byte[] data, int start, int length);
+	public void reset(byte[] data, int start, int length);
 }
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/IBinaryTokenizerFactory.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/IBinaryTokenizerFactory.java
index e6b9286..bfe78ee 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/IBinaryTokenizerFactory.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/IBinaryTokenizerFactory.java
@@ -22,5 +22,5 @@
 import java.io.Serializable;
 
 public interface IBinaryTokenizerFactory extends Serializable {
-    public IBinaryTokenizer createTokenizer();
+	public IBinaryTokenizer createTokenizer();
 }
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/INGramToken.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/INGramToken.java
index 183c421..befc6d2 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/INGramToken.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/INGramToken.java
@@ -20,9 +20,9 @@
 package edu.uci.ics.hyracks.storage.am.invertedindex.tokenizers;
 
 public interface INGramToken {
-    public int getNumPostChars();
+	public int getNumPostChars();
 
-    public int getNumPreChars();
+	public int getNumPreChars();
 
-    public void setNumPrePostChars(int numPreChars, int numPostChars);
+	public void setNumPrePostChars(int numPreChars, int numPostChars);
 }
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/IToken.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/IToken.java
index 0f6e34a..c1840d7 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/IToken.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/IToken.java
@@ -23,17 +23,18 @@
 import java.io.IOException;
 
 public interface IToken {
-    public byte[] getData();
+	public byte[] getData();
 
-    public int getLength();
+	public int getLength();
 
-    public int getStart();
+	public int getStart();
 
-    public int getTokenLength();
+	public int getTokenLength();
 
-    public void reset(byte[] data, int start, int length, int tokenLength, int tokenCount);
+	public void reset(byte[] data, int start, int length, int tokenLength,
+			int tokenCount);
 
-    public void serializeToken(DataOutput dos) throws IOException;
+	public void serializeToken(DataOutput dos) throws IOException;
 
-    public void serializeTokenCount(DataOutput dos) throws IOException;
+	public void serializeTokenCount(DataOutput dos) throws IOException;
 }
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/NGramUTF8StringBinaryTokenizer.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/NGramUTF8StringBinaryTokenizer.java
index 746ee1d..fdfc02f 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/NGramUTF8StringBinaryTokenizer.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/NGramUTF8StringBinaryTokenizer.java
@@ -19,7 +19,7 @@
 
 package edu.uci.ics.hyracks.storage.am.invertedindex.tokenizers;
 
-import edu.uci.ics.hyracks.dataflow.common.data.util.StringUtils;
+import edu.uci.ics.hyracks.data.std.primitive.UTF8StringPointable;
 
 public class NGramUTF8StringBinaryTokenizer extends AbstractUTF8StringBinaryTokenizer {
 
@@ -62,7 +62,7 @@
 
         concreteToken.setNumPrePostChars(numPreChars, numPostChars);
         if (numPreChars == 0) {
-            index += StringUtils.charSize(data, index);
+            index += UTF8StringPointable.charSize(data, index);
         }
 
         // compute token count
@@ -73,13 +73,14 @@
                 tokenCount++; // assume found
                 int offset = 0;
                 for (int j = 0; j < gramLength; j++) {
-                    if (Character.toLowerCase(StringUtils.charAt(data, currentTokenStart + offset)) != Character.toLowerCase(StringUtils.charAt(data, tmpIndex + offset))) {
+                    if (Character.toLowerCase(UTF8StringPointable.charAt(data, currentTokenStart + offset)) != Character
+                            .toLowerCase(UTF8StringPointable.charAt(data, tmpIndex + offset))) {
                         tokenCount--;
                         break;
                     }
-                    offset += StringUtils.charSize(data, tmpIndex + offset);
+                    offset += UTF8StringPointable.charSize(data, tmpIndex + offset);
                 }
-                tmpIndex += StringUtils.charSize(data, tmpIndex);
+                tmpIndex += UTF8StringPointable.charSize(data, tmpIndex);
             }
         }
 
@@ -97,7 +98,7 @@
         int end = pos + utf8Length;
         while (pos < end) {
             numChars++;
-            pos += StringUtils.charSize(data, pos);
+            pos += UTF8StringPointable.charSize(data, pos);
         }
 
         if (usePrePost) {
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/UTF8NGramToken.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/UTF8NGramToken.java
index 1b124dc..59cadc8 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/UTF8NGramToken.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/UTF8NGramToken.java
@@ -22,6 +22,7 @@
 import java.io.DataOutput;
 import java.io.IOException;
 
+import edu.uci.ics.hyracks.data.std.primitive.UTF8StringPointable;
 import edu.uci.ics.hyracks.dataflow.common.data.util.StringUtils;
 
 public class UTF8NGramToken extends AbstractUTF8Token implements INGramToken {
@@ -67,9 +68,9 @@
 
         int pos = start;
         for (int i = 0; i < numRegChars; i++) {
-            char c = Character.toLowerCase(StringUtils.charAt(data, pos));
+            char c = Character.toLowerCase(UTF8StringPointable.charAt(data, pos));
             StringUtils.writeCharAsModifiedUTF8(c, dos);
-            pos += StringUtils.charSize(data, pos);
+            pos += UTF8StringPointable.charSize(data, pos);
         }
 
         // post chars
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/UTF8NGramTokenFactory.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/UTF8NGramTokenFactory.java
index 7a72caa..968d8e1 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/UTF8NGramTokenFactory.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/UTF8NGramTokenFactory.java
@@ -21,19 +21,19 @@
 
 public class UTF8NGramTokenFactory extends AbstractUTF8TokenFactory {
 
-    private static final long serialVersionUID = 1L;
+	private static final long serialVersionUID = 1L;
 
-    public UTF8NGramTokenFactory() {
-        super();
-    }
+	public UTF8NGramTokenFactory() {
+		super();
+	}
 
-    public UTF8NGramTokenFactory(byte tokenTypeTag, byte countTypeTag) {
-        super(tokenTypeTag, countTypeTag);
-    }
+	public UTF8NGramTokenFactory(byte tokenTypeTag, byte countTypeTag) {
+		super(tokenTypeTag, countTypeTag);
+	}
 
-    @Override
-    public IToken createToken() {
-        return new UTF8NGramToken(tokenTypeTag, countTypeTag);
-    }
+	@Override
+	public IToken createToken() {
+		return new UTF8NGramToken(tokenTypeTag, countTypeTag);
+	}
 
 }
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/UTF8WordToken.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/UTF8WordToken.java
index 2a74145..97a1e12 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/UTF8WordToken.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/UTF8WordToken.java
@@ -22,6 +22,7 @@
 import java.io.DataOutput;
 import java.io.IOException;
 
+import edu.uci.ics.hyracks.data.std.primitive.UTF8StringPointable;
 import edu.uci.ics.hyracks.dataflow.common.data.util.StringUtils;
 
 public class UTF8WordToken extends AbstractUTF8Token {
@@ -38,9 +39,9 @@
         StringUtils.writeUTF8Len(tokenUTF8Len, dos);
         int pos = start;
         for (int i = 0; i < tokenLength; i++) {
-            char c = Character.toLowerCase(StringUtils.charAt(data, pos));
+            char c = Character.toLowerCase(UTF8StringPointable.charAt(data, pos));
             StringUtils.writeCharAsModifiedUTF8(c, dos);
-            pos += StringUtils.charSize(data, pos);
+            pos += UTF8StringPointable.charSize(data, pos);
         }
     }
 }
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/UTF8WordTokenFactory.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/UTF8WordTokenFactory.java
index 471747b..4358254 100644
--- a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/UTF8WordTokenFactory.java
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/tokenizers/UTF8WordTokenFactory.java
@@ -21,19 +21,19 @@
 
 public class UTF8WordTokenFactory extends AbstractUTF8TokenFactory {
 
-    private static final long serialVersionUID = 1L;
+	private static final long serialVersionUID = 1L;
 
-    public UTF8WordTokenFactory() {
-        super();
-    }
+	public UTF8WordTokenFactory() {
+		super();
+	}
 
-    public UTF8WordTokenFactory(byte tokenTypeTag, byte countTypeTag) {
-        super(tokenTypeTag, countTypeTag);
-    }
+	public UTF8WordTokenFactory(byte tokenTypeTag, byte countTypeTag) {
+		super(tokenTypeTag, countTypeTag);
+	}
 
-    @Override
-    public IToken createToken() {
-        return new UTF8WordToken(tokenTypeTag, countTypeTag);
-    }
+	@Override
+	public IToken createToken() {
+		return new UTF8WordToken(tokenTypeTag, countTypeTag);
+	}
 
 }
diff --git a/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/util/InvertedIndexUtils.java b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/util/InvertedIndexUtils.java
new file mode 100644
index 0000000..a1d1f06
--- /dev/null
+++ b/hyracks/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/util/InvertedIndexUtils.java
@@ -0,0 +1,47 @@
+/*
+ * Copyright 2009-2010 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.invertedindex.util;
+
+import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
+import edu.uci.ics.hyracks.data.std.primitive.IntegerPointable;
+
+public class InvertedIndexUtils {
+    // Type traits to be appended to the token type trait which finally form the BTree field type traits.
+    private static final ITypeTraits[] btreeValueTypeTraits = new ITypeTraits[4];
+    static {
+        // startPageId
+        btreeValueTypeTraits[0] = IntegerPointable.TYPE_TRAITS;
+        // endPageId
+        btreeValueTypeTraits[1] = IntegerPointable.TYPE_TRAITS;
+        // startOff
+        btreeValueTypeTraits[2] = IntegerPointable.TYPE_TRAITS;
+        // numElements
+        btreeValueTypeTraits[3] = IntegerPointable.TYPE_TRAITS;
+    }
+
+    public static ITypeTraits[] getBTreeTypeTraits(ITypeTraits[] tokenTypeTraits) {
+        ITypeTraits[] btreeTypeTraits = new ITypeTraits[tokenTypeTraits.length + btreeValueTypeTraits.length];
+        // Set key type traits.
+        for (int i = 0; i < tokenTypeTraits.length; i++) {
+            btreeTypeTraits[i] = tokenTypeTraits[i];
+        }
+        // Set value type traits.
+        for (int i = 0; i < btreeValueTypeTraits.length; i++) {
+            btreeTypeTraits[i + tokenTypeTraits.length] = btreeValueTypeTraits[i];
+        }
+        return btreeTypeTraits;
+    }
+}