diff --git a/hivesterix-optimizer/pom.xml b/hivesterix-optimizer/pom.xml
new file mode 100644
index 0000000..4e6032e
--- /dev/null
+++ b/hivesterix-optimizer/pom.xml
@@ -0,0 +1,47 @@
+<?xml version="1.0"?>
+<project
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<artifactId>hivesterix</artifactId>
+		<groupId>edu.uci.ics.hyracks</groupId>
+		<version>0.2.3-SNAPSHOT</version>
+	</parent>
+
+	<artifactId>hivesterix-optimizer</artifactId>
+	<name>hivesterix-optimizer</name>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-compiler-plugin</artifactId>
+				<version>2.0.2</version>
+				<configuration>
+					<source>1.7</source>
+					<target>1.7</target>
+					<encoding>UTF-8</encoding>
+					<fork>true</fork>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+
+	<dependencies>
+		<dependency>
+			<groupId>edu.uci.ics.hyracks</groupId>
+			<artifactId>hivesterix-common</artifactId>
+			<version>0.2.3-SNAPSHOT</version>
+			<type>jar</type>
+			<scope>compile</scope>
+		</dependency>
+		<dependency>
+			<groupId>edu.uci.ics.hyracks</groupId>
+			<artifactId>hivesterix-translator</artifactId>
+			<version>0.2.3-SNAPSHOT</version>
+			<type>jar</type>
+			<scope>compile</scope>
+		</dependency>
+	</dependencies>
+</project>
diff --git a/hivesterix-optimizer/src/main/java/edu/uci/ics/hivesterix/optimizer/rulecollections/HiveRuleCollections.java b/hivesterix-optimizer/src/main/java/edu/uci/ics/hivesterix/optimizer/rulecollections/HiveRuleCollections.java
new file mode 100644
index 0000000..7e4e271
--- /dev/null
+++ b/hivesterix-optimizer/src/main/java/edu/uci/ics/hivesterix/optimizer/rulecollections/HiveRuleCollections.java
@@ -0,0 +1,113 @@
+package edu.uci.ics.hivesterix.optimizer.rulecollections;
+
+import java.util.LinkedList;
+
+import edu.uci.ics.hivesterix.optimizer.rules.InsertProjectBeforeWriteRule;
+import edu.uci.ics.hivesterix.optimizer.rules.IntroduceEarlyProjectRule;
+import edu.uci.ics.hivesterix.optimizer.rules.LocalGroupByRule;
+import edu.uci.ics.hivesterix.optimizer.rules.RemoveRedundantSelectRule;
+import edu.uci.ics.hyracks.algebricks.core.rewriter.base.HeuristicOptimizer;
+import edu.uci.ics.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.BreakSelectIntoConjunctsRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.ComplexJoinInferenceRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.ConsolidateAssignsRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.ConsolidateSelectsRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.EliminateSubplanRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.EnforceStructuralPropertiesRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.ExtractCommonOperatorsRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.ExtractGbyExpressionsRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.FactorRedundantGroupAndDecorVarsRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.InferTypesRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.InlineVariablesRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.InsertProjectBeforeUnionRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.IntroduceAggregateCombinerRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.IntroduceGroupByCombinerRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.IsolateHyracksOperatorsRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.PullSelectOutOfEqJoin;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.PushLimitDownRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.PushProjectDownRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.PushProjectIntoDataSourceScanRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.PushSelectDownRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.PushSelectIntoJoinRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.ReinferAllTypesRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.RemoveRedundantProjectionRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.RemoveUnusedAssignAndAggregateRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.SetAlgebricksPhysicalOperatorsRule;
+import edu.uci.ics.hyracks.algebricks.rewriter.rules.SetExecutionModeRule;
+
+public final class HiveRuleCollections {
+
+    public final static LinkedList<IAlgebraicRewriteRule> NORMALIZATION = new LinkedList<IAlgebraicRewriteRule>();
+    static {
+        NORMALIZATION.add(new EliminateSubplanRule());
+        NORMALIZATION.add(new IntroduceAggregateCombinerRule());
+        NORMALIZATION.add(new BreakSelectIntoConjunctsRule());
+        NORMALIZATION.add(new IntroduceAggregateCombinerRule());
+        NORMALIZATION.add(new PushSelectIntoJoinRule());
+        NORMALIZATION.add(new ExtractGbyExpressionsRule());
+        NORMALIZATION.add(new RemoveRedundantSelectRule());
+    }
+
+    public final static LinkedList<IAlgebraicRewriteRule> COND_PUSHDOWN_AND_JOIN_INFERENCE = new LinkedList<IAlgebraicRewriteRule>();
+    static {
+        COND_PUSHDOWN_AND_JOIN_INFERENCE.add(new PushSelectDownRule());
+        COND_PUSHDOWN_AND_JOIN_INFERENCE.add(new InlineVariablesRule());
+        COND_PUSHDOWN_AND_JOIN_INFERENCE.add(new FactorRedundantGroupAndDecorVarsRule());
+        COND_PUSHDOWN_AND_JOIN_INFERENCE.add(new EliminateSubplanRule());
+    }
+
+    public final static LinkedList<IAlgebraicRewriteRule> LOAD_FIELDS = new LinkedList<IAlgebraicRewriteRule>();
+    static {
+        // should LoadRecordFieldsRule be applied in only one pass over the
+        // plan?
+        LOAD_FIELDS.add(new InlineVariablesRule());
+        // LOAD_FIELDS.add(new RemoveUnusedAssignAndAggregateRule());
+        LOAD_FIELDS.add(new ComplexJoinInferenceRule());
+        LOAD_FIELDS.add(new InferTypesRule());
+    }
+
+    public final static LinkedList<IAlgebraicRewriteRule> OP_PUSHDOWN = new LinkedList<IAlgebraicRewriteRule>();
+    static {
+        OP_PUSHDOWN.add(new PushProjectDownRule());
+        OP_PUSHDOWN.add(new PushSelectDownRule());
+    }
+
+    public final static LinkedList<IAlgebraicRewriteRule> DATA_EXCHANGE = new LinkedList<IAlgebraicRewriteRule>();
+    static {
+        DATA_EXCHANGE.add(new SetExecutionModeRule());
+    }
+
+    public final static LinkedList<IAlgebraicRewriteRule> CONSOLIDATION = new LinkedList<IAlgebraicRewriteRule>();
+    static {
+        CONSOLIDATION.add(new RemoveRedundantProjectionRule());
+        CONSOLIDATION.add(new ConsolidateSelectsRule());
+        CONSOLIDATION.add(new IntroduceEarlyProjectRule());
+        CONSOLIDATION.add(new ConsolidateAssignsRule());
+        CONSOLIDATION.add(new IntroduceGroupByCombinerRule());
+        CONSOLIDATION.add(new RemoveUnusedAssignAndAggregateRule());
+    }
+
+    public final static LinkedList<IAlgebraicRewriteRule> PHYSICAL_PLAN_REWRITES = new LinkedList<IAlgebraicRewriteRule>();
+    static {
+        PHYSICAL_PLAN_REWRITES.add(new PullSelectOutOfEqJoin());
+        PHYSICAL_PLAN_REWRITES.add(new SetAlgebricksPhysicalOperatorsRule());
+        PHYSICAL_PLAN_REWRITES.add(new EnforceStructuralPropertiesRule());
+        PHYSICAL_PLAN_REWRITES.add(new PushProjectDownRule());
+        PHYSICAL_PLAN_REWRITES.add(new SetAlgebricksPhysicalOperatorsRule());
+        PHYSICAL_PLAN_REWRITES.add(new PushLimitDownRule());
+        PHYSICAL_PLAN_REWRITES.add(new InsertProjectBeforeWriteRule());
+        PHYSICAL_PLAN_REWRITES.add(new InsertProjectBeforeUnionRule());
+    }
+
+    public final static LinkedList<IAlgebraicRewriteRule> prepareJobGenRules = new LinkedList<IAlgebraicRewriteRule>();
+    static {
+        prepareJobGenRules.add(new ReinferAllTypesRule());
+        prepareJobGenRules.add(new IsolateHyracksOperatorsRule(
+                HeuristicOptimizer.hyraxOperatorsBelowWhichJobGenIsDisabled));
+        prepareJobGenRules.add(new ExtractCommonOperatorsRule());
+        prepareJobGenRules.add(new LocalGroupByRule());
+        prepareJobGenRules.add(new PushProjectIntoDataSourceScanRule());
+        prepareJobGenRules.add(new ReinferAllTypesRule());
+    }
+
+}
diff --git a/hivesterix-optimizer/src/main/java/edu/uci/ics/hivesterix/optimizer/rules/InsertProjectBeforeWriteRule.java b/hivesterix-optimizer/src/main/java/edu/uci/ics/hivesterix/optimizer/rules/InsertProjectBeforeWriteRule.java
new file mode 100644
index 0000000..90777ee
--- /dev/null
+++ b/hivesterix-optimizer/src/main/java/edu/uci/ics/hivesterix/optimizer/rules/InsertProjectBeforeWriteRule.java
@@ -0,0 +1,79 @@
+package edu.uci.ics.hivesterix.optimizer.rules;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.commons.lang3.mutable.Mutable;
+import org.apache.commons.lang3.mutable.MutableObject;
+
+import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.IOptimizationContext;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalOperatorTag;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalVariable;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.AbstractLogicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.AbstractLogicalOperator.ExecutionMode;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.ProjectOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.WriteOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.visitors.VariableUtilities;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.physical.StreamProjectPOperator;
+import edu.uci.ics.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule;
+
+public class InsertProjectBeforeWriteRule implements IAlgebraicRewriteRule {
+
+    @Override
+    public boolean rewritePost(Mutable<ILogicalOperator> opRef, IOptimizationContext context) {
+        return false;
+    }
+
+    /**
+     * When the input schema to WriteOperator is different from the output
+     * schema in terms of variable order, add a project operator to get the
+     * write order
+     */
+    @Override
+    public boolean rewritePre(Mutable<ILogicalOperator> opRef, IOptimizationContext context) throws AlgebricksException {
+        AbstractLogicalOperator op = (AbstractLogicalOperator) opRef.getValue();
+        if (op.getOperatorTag() != LogicalOperatorTag.WRITE) {
+            return false;
+        }
+        WriteOperator opWrite = (WriteOperator) op;
+        ArrayList<LogicalVariable> finalSchema = new ArrayList<LogicalVariable>();
+        VariableUtilities.getUsedVariables(opWrite, finalSchema);
+        ArrayList<LogicalVariable> inputSchema = new ArrayList<LogicalVariable>();
+        VariableUtilities.getLiveVariables(opWrite, inputSchema);
+        if (!isIdentical(finalSchema, inputSchema)) {
+            ProjectOperator projectOp = new ProjectOperator(finalSchema);
+            Mutable<ILogicalOperator> parentOpRef = opWrite.getInputs().get(0);
+            projectOp.getInputs().add(parentOpRef);
+            opWrite.getInputs().clear();
+            opWrite.getInputs().add(new MutableObject<ILogicalOperator>(projectOp));
+            projectOp.setPhysicalOperator(new StreamProjectPOperator());
+            projectOp.setExecutionMode(ExecutionMode.PARTITIONED);
+
+            AbstractLogicalOperator op2 = (AbstractLogicalOperator) parentOpRef.getValue();
+            if (op2.getOperatorTag() == LogicalOperatorTag.PROJECT) {
+                ProjectOperator pi2 = (ProjectOperator) op2;
+                parentOpRef.setValue(pi2.getInputs().get(0).getValue());
+            }
+            context.computeAndSetTypeEnvironmentForOperator(projectOp);
+            return true;
+        } else
+            return false;
+
+    }
+
+    private boolean isIdentical(List<LogicalVariable> finalSchema, List<LogicalVariable> inputSchema) {
+        int finalSchemaSize = finalSchema.size();
+        int inputSchemaSize = inputSchema.size();
+        if (finalSchemaSize != inputSchemaSize)
+            throw new IllegalStateException("final output schema variables missing!");
+        for (int i = 0; i < finalSchemaSize; i++) {
+            LogicalVariable var1 = finalSchema.get(i);
+            LogicalVariable var2 = inputSchema.get(i);
+            if (!var1.equals(var2))
+                return false;
+        }
+        return true;
+    }
+}
diff --git a/hivesterix-optimizer/src/main/java/edu/uci/ics/hivesterix/optimizer/rules/IntroduceEarlyProjectRule.java b/hivesterix-optimizer/src/main/java/edu/uci/ics/hivesterix/optimizer/rules/IntroduceEarlyProjectRule.java
new file mode 100644
index 0000000..0a18629
--- /dev/null
+++ b/hivesterix-optimizer/src/main/java/edu/uci/ics/hivesterix/optimizer/rules/IntroduceEarlyProjectRule.java
@@ -0,0 +1,73 @@
+package edu.uci.ics.hivesterix.optimizer.rules;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import org.apache.commons.lang3.mutable.Mutable;
+import org.apache.commons.lang3.mutable.MutableObject;
+
+import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.IOptimizationContext;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalOperatorTag;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalVariable;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.AbstractLogicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.ProjectOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.visitors.VariableUtilities;
+import edu.uci.ics.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule;
+
+public class IntroduceEarlyProjectRule implements IAlgebraicRewriteRule {
+
+    @Override
+    public boolean rewritePre(Mutable<ILogicalOperator> opRef, IOptimizationContext context) throws AlgebricksException {
+        return false;
+    }
+
+    @Override
+    public boolean rewritePost(Mutable<ILogicalOperator> opRef, IOptimizationContext context)
+            throws AlgebricksException {
+        AbstractLogicalOperator op = (AbstractLogicalOperator) opRef.getValue();
+        if (op.getOperatorTag() != LogicalOperatorTag.PROJECT) {
+            return false;
+        }
+        AbstractLogicalOperator middleOp = (AbstractLogicalOperator) op.getInputs().get(0).getValue();
+        List<LogicalVariable> deliveredVars = new ArrayList<LogicalVariable>();
+        List<LogicalVariable> usedVars = new ArrayList<LogicalVariable>();
+        List<LogicalVariable> producedVars = new ArrayList<LogicalVariable>();
+
+        VariableUtilities.getUsedVariables(op, deliveredVars);
+        VariableUtilities.getUsedVariables(middleOp, usedVars);
+        VariableUtilities.getProducedVariables(middleOp, producedVars);
+
+        Set<LogicalVariable> requiredVariables = new HashSet<LogicalVariable>();
+        requiredVariables.addAll(deliveredVars);
+        requiredVariables.addAll(usedVars);
+        requiredVariables.removeAll(producedVars);
+
+        if (middleOp.getInputs().size() <= 0 || middleOp.getInputs().size() > 1)
+            return false;
+
+        AbstractLogicalOperator targetOp = (AbstractLogicalOperator) middleOp.getInputs().get(0).getValue();
+        if (targetOp.getOperatorTag() != LogicalOperatorTag.DATASOURCESCAN)
+            return false;
+
+        Set<LogicalVariable> deliveredEarlyVars = new HashSet<LogicalVariable>();
+        VariableUtilities.getLiveVariables(targetOp, deliveredEarlyVars);
+
+        deliveredEarlyVars.removeAll(requiredVariables);
+        if (deliveredEarlyVars.size() > 0) {
+            ArrayList<LogicalVariable> requiredVars = new ArrayList<LogicalVariable>();
+            requiredVars.addAll(requiredVariables);
+            ILogicalOperator earlyProjectOp = new ProjectOperator(requiredVars);
+            Mutable<ILogicalOperator> earlyProjectOpRef = new MutableObject<ILogicalOperator>(earlyProjectOp);
+            Mutable<ILogicalOperator> targetRef = middleOp.getInputs().get(0);
+            middleOp.getInputs().set(0, earlyProjectOpRef);
+            earlyProjectOp.getInputs().add(targetRef);
+            context.computeAndSetTypeEnvironmentForOperator(earlyProjectOp);
+            return true;
+        }
+        return false;
+    }
+}
diff --git a/hivesterix-optimizer/src/main/java/edu/uci/ics/hivesterix/optimizer/rules/LocalGroupByRule.java b/hivesterix-optimizer/src/main/java/edu/uci/ics/hivesterix/optimizer/rules/LocalGroupByRule.java
new file mode 100644
index 0000000..90ca008
--- /dev/null
+++ b/hivesterix-optimizer/src/main/java/edu/uci/ics/hivesterix/optimizer/rules/LocalGroupByRule.java
@@ -0,0 +1,66 @@
+package edu.uci.ics.hivesterix.optimizer.rules;
+
+import org.apache.commons.lang3.mutable.Mutable;
+
+import edu.uci.ics.hivesterix.logical.plan.HiveOperatorAnnotations;
+import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.IOptimizationContext;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.IPhysicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalOperatorTag;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.OperatorAnnotations;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.PhysicalOperatorTag;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.AbstractLogicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.ExchangeOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.physical.OneToOneExchangePOperator;
+import edu.uci.ics.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule;
+
+public class LocalGroupByRule implements IAlgebraicRewriteRule {
+
+    @Override
+    public boolean rewritePre(Mutable<ILogicalOperator> opRef, IOptimizationContext context) throws AlgebricksException {
+        return false;
+    }
+
+    @Override
+    public boolean rewritePost(Mutable<ILogicalOperator> opRef, IOptimizationContext context)
+            throws AlgebricksException {
+        AbstractLogicalOperator op = (AbstractLogicalOperator) opRef.getValue();
+        if (op.getOperatorTag() != LogicalOperatorTag.GROUP) {
+            return false;
+        }
+        Boolean localGby = (Boolean) op.getAnnotations().get(HiveOperatorAnnotations.LOCAL_GROUP_BY);
+        if (localGby != null && localGby.equals(Boolean.TRUE)) {
+            Boolean hashGby = (Boolean) op.getAnnotations().get(OperatorAnnotations.USE_HASH_GROUP_BY);
+            Boolean externalGby = (Boolean) op.getAnnotations().get(OperatorAnnotations.USE_EXTERNAL_GROUP_BY);
+            if ((hashGby != null && (hashGby.equals(Boolean.TRUE)) || (externalGby != null && externalGby
+                    .equals(Boolean.TRUE)))) {
+                reviseExchange(op);
+            } else {
+                ILogicalOperator child = op.getInputs().get(0).getValue();
+                AbstractLogicalOperator childOp = (AbstractLogicalOperator) child;
+                while (child.getInputs().size() > 0) {
+                    if (childOp.getOperatorTag() == LogicalOperatorTag.ORDER)
+                        break;
+                    else {
+                        child = child.getInputs().get(0).getValue();
+                        childOp = (AbstractLogicalOperator) child;
+                    }
+                }
+                if (childOp.getOperatorTag() == LogicalOperatorTag.ORDER)
+                    reviseExchange(childOp);
+            }
+            return true;
+        }
+        return false;
+    }
+
+    private void reviseExchange(AbstractLogicalOperator op) {
+        ExchangeOperator exchange = (ExchangeOperator) op.getInputs().get(0).getValue();
+        IPhysicalOperator physicalOp = exchange.getPhysicalOperator();
+        if (physicalOp.getOperatorTag() == PhysicalOperatorTag.HASH_PARTITION_EXCHANGE) {
+            exchange.setPhysicalOperator(new OneToOneExchangePOperator());
+        }
+    }
+
+}
diff --git a/hivesterix-optimizer/src/main/java/edu/uci/ics/hivesterix/optimizer/rules/RemoveRedundantSelectRule.java b/hivesterix-optimizer/src/main/java/edu/uci/ics/hivesterix/optimizer/rules/RemoveRedundantSelectRule.java
new file mode 100644
index 0000000..44ff12d
--- /dev/null
+++ b/hivesterix-optimizer/src/main/java/edu/uci/ics/hivesterix/optimizer/rules/RemoveRedundantSelectRule.java
@@ -0,0 +1,44 @@
+package edu.uci.ics.hivesterix.optimizer.rules;
+
+import org.apache.commons.lang3.mutable.Mutable;
+
+import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.IOptimizationContext;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalOperatorTag;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.AbstractLogicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.SelectOperator;
+import edu.uci.ics.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule;
+
+public class RemoveRedundantSelectRule implements IAlgebraicRewriteRule {
+
+    @Override
+    public boolean rewritePre(Mutable<ILogicalOperator> opRef, IOptimizationContext context) throws AlgebricksException {
+        return false;
+    }
+
+    @Override
+    public boolean rewritePost(Mutable<ILogicalOperator> opRef, IOptimizationContext context)
+            throws AlgebricksException {
+        AbstractLogicalOperator op = (AbstractLogicalOperator) opRef.getValue();
+        if (op.getOperatorTag() != LogicalOperatorTag.SELECT) {
+            return false;
+        }
+        AbstractLogicalOperator inputOp = (AbstractLogicalOperator) op.getInputs().get(0).getValue();
+        if (inputOp.getOperatorTag() != LogicalOperatorTag.SELECT) {
+            return false;
+        }
+        SelectOperator selectOp = (SelectOperator) op;
+        SelectOperator inputSelectOp = (SelectOperator) inputOp;
+        ILogicalExpression expr1 = selectOp.getCondition().getValue();
+        ILogicalExpression expr2 = inputSelectOp.getCondition().getValue();
+
+        if (expr1.equals(expr2)) {
+            selectOp.getInputs().set(0, inputSelectOp.getInputs().get(0));
+            return true;
+        }
+        return false;
+    }
+
+}