| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 at |
| * |
| * 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 org.apache.hyracks.algebricks.rewriter.rules; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import org.apache.commons.lang3.mutable.Mutable; |
| import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException; |
| import org.apache.hyracks.algebricks.core.algebra.base.ILogicalOperator; |
| import org.apache.hyracks.algebricks.core.algebra.base.IOptimizationContext; |
| import org.apache.hyracks.algebricks.core.algebra.base.LogicalOperatorTag; |
| import org.apache.hyracks.algebricks.core.algebra.base.LogicalVariable; |
| import org.apache.hyracks.algebricks.core.algebra.operators.logical.AbstractBinaryJoinOperator; |
| import org.apache.hyracks.algebricks.core.algebra.operators.logical.AbstractLogicalOperator; |
| import org.apache.hyracks.algebricks.core.algebra.operators.logical.visitors.VariableUtilities; |
| import org.apache.hyracks.algebricks.core.algebra.util.OperatorPropertiesUtil; |
| import org.apache.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule; |
| |
| public class PushMapOperatorDownThroughProductRule 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(); |
| // Even the LIMIT operator is a map operator, we don't push LIMIT operator into a join |
| // since a new LIMIT under a join can't generate the original result. |
| if (!op1.isMap() || op1.getOperatorTag() == LogicalOperatorTag.LIMIT) { |
| 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 (!OperatorPropertiesUtil.isAlwaysTrueCond(join.getCondition().getValue())) { |
| 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 operator 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 operator on right branch |
| op2Ref.setValue(b1); |
| b1Ref.setValue(op1); |
| opRef.setValue(op2); |
| return true; |
| } else { |
| return false; |
| } |
| } |
| } |
| |
| } |