Merge branch 'master' of https://code.google.com/p/hyracks into icetindil/issue_352
diff --git a/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/PushUnnestDownThroughProductRule.java b/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/PushUnnestDownThroughProductRule.java
new file mode 100644
index 0000000..c70fca9
--- /dev/null
+++ b/algebricks/algebricks-rewriter/src/main/java/edu/uci/ics/hyracks/algebricks/rewriter/rules/PushUnnestDownThroughProductRule.java
@@ -0,0 +1,87 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.algebricks.rewriter.rules;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.commons.lang3.mutable.Mutable;
+
+import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.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.expressions.ConstantExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.AbstractBinaryJoinOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.AbstractLogicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.visitors.VariableUtilities;
+import edu.uci.ics.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule;
+
+public class PushUnnestDownThroughProductRule 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 op1 = (AbstractLogicalOperator) opRef.getValue();
+ if (op1.getOperatorTag() != LogicalOperatorTag.UNNEST) {
+ return false;
+ }
+ Mutable<ILogicalOperator> op2Ref = op1.getInputs().get(0);
+ AbstractLogicalOperator op2 = (AbstractLogicalOperator) op2Ref.getValue();
+ if (op2.getOperatorTag() != LogicalOperatorTag.INNERJOIN) {
+ return false;
+ }
+ AbstractBinaryJoinOperator join = (AbstractBinaryJoinOperator) op2;
+ if (join.getCondition().getValue() != ConstantExpression.TRUE) {
+ return false;
+ }
+
+ List<LogicalVariable> used = new ArrayList<LogicalVariable>();
+ VariableUtilities.getUsedVariables(op1, used);
+
+ Mutable<ILogicalOperator> b0Ref = op2.getInputs().get(0);
+ ILogicalOperator b0 = b0Ref.getValue();
+ List<LogicalVariable> b0Scm = new ArrayList<LogicalVariable>();
+ VariableUtilities.getLiveVariables(b0, b0Scm);
+ if (b0Scm.containsAll(used)) {
+ // push unnest on left branch
+ op2Ref.setValue(b0);
+ b0Ref.setValue(op1);
+ opRef.setValue(op2);
+ return true;
+ } else {
+ Mutable<ILogicalOperator> b1Ref = op2.getInputs().get(1);
+ ILogicalOperator b1 = b1Ref.getValue();
+ List<LogicalVariable> b1Scm = new ArrayList<LogicalVariable>();
+ VariableUtilities.getLiveVariables(b1, b1Scm);
+ if (b1Scm.containsAll(used)) {
+ // push unnest on right branch
+ op2Ref.setValue(b1);
+ b1Ref.setValue(op1);
+ opRef.setValue(op2);
+ return true;
+ } else {
+ return false;
+ }
+ }
+ }
+
+}