| /* |
| * 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.algebricks.rewriter.rules; |
| |
| import java.util.LinkedList; |
| 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.operators.logical.AbstractLogicalOperator; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.SelectOperator; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.visitors.VariableUtilities; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.util.OperatorPropertiesUtil; |
| import edu.uci.ics.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule; |
| |
| public class PushSelectDownRule implements IAlgebraicRewriteRule { |
| |
| @Override |
| public boolean rewritePost(Mutable<ILogicalOperator> opRef, IOptimizationContext context) { |
| return false; |
| } |
| |
| @Override |
| public boolean rewritePre(Mutable<ILogicalOperator> opRef, IOptimizationContext context) throws AlgebricksException { |
| AbstractLogicalOperator op = (AbstractLogicalOperator) opRef.getValue(); |
| if (op.getOperatorTag() != LogicalOperatorTag.SELECT) { |
| return false; |
| } |
| |
| Mutable<ILogicalOperator> opRef2 = op.getInputs().get(0); |
| AbstractLogicalOperator op2 = (AbstractLogicalOperator) opRef2.getValue(); |
| |
| if (context.checkAndAddToAlreadyCompared(op, op2)) { |
| return false; |
| } |
| |
| LogicalOperatorTag tag2 = op2.getOperatorTag(); |
| |
| if (tag2 == LogicalOperatorTag.INNERJOIN || tag2 == LogicalOperatorTag.LEFTOUTERJOIN |
| || tag2 == LogicalOperatorTag.REPLICATE) { |
| return false; |
| } else { // not a join |
| boolean res = propagateSelectionRec(opRef, opRef2); |
| if (res) { |
| OperatorPropertiesUtil.typeOpRec(opRef, context); |
| } |
| return res; |
| } |
| } |
| |
| private static boolean propagateSelectionRec(Mutable<ILogicalOperator> sigmaRef, Mutable<ILogicalOperator> opRef2) |
| throws AlgebricksException { |
| AbstractLogicalOperator op2 = (AbstractLogicalOperator) opRef2.getValue(); |
| if (op2.getInputs().size() != 1 || op2.getOperatorTag() == LogicalOperatorTag.DATASOURCESCAN) { |
| return false; |
| } |
| |
| SelectOperator sigma = (SelectOperator) sigmaRef.getValue(); |
| LinkedList<LogicalVariable> usedInSigma = new LinkedList<LogicalVariable>(); |
| sigma.getCondition().getValue().getUsedVariables(usedInSigma); |
| |
| LinkedList<LogicalVariable> produced2 = new LinkedList<LogicalVariable>(); |
| VariableUtilities.getProducedVariables(op2, produced2); |
| if (OperatorPropertiesUtil.disjoint(produced2, usedInSigma)) { |
| // just swap |
| opRef2.setValue(sigma); |
| sigmaRef.setValue(op2); |
| List<Mutable<ILogicalOperator>> sigmaInpList = sigma.getInputs(); |
| sigmaInpList.clear(); |
| sigmaInpList.addAll(op2.getInputs()); |
| List<Mutable<ILogicalOperator>> op2InpList = op2.getInputs(); |
| op2InpList.clear(); |
| op2InpList.add(opRef2); |
| propagateSelectionRec(opRef2, sigma.getInputs().get(0)); |
| return true; |
| |
| } |
| return false; |
| } |
| |
| } |