| /* |
| * 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.ArrayList; |
| import java.util.Iterator; |
| 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.ILogicalPlan; |
| 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.GroupByOperator; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.SubplanOperator; |
| 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; |
| |
| /** |
| * Looks for a nested group-by plan ending in |
| * subplan { |
| * ... |
| * } |
| * select (function-call: algebricks:not, Args:[function-call: |
| * algebricks:is-null, Args:[...]]) |
| * nested tuple source -- |UNPARTITIONED| |
| */ |
| |
| public class SubplanOutOfGroupRule 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 op0 = (AbstractLogicalOperator) opRef.getValue(); |
| if (op0.getOperatorTag() != LogicalOperatorTag.GROUP) { |
| return false; |
| } |
| GroupByOperator gby = (GroupByOperator) op0; |
| |
| Iterator<ILogicalPlan> plansIter = gby.getNestedPlans().iterator(); |
| ILogicalPlan p = null; |
| while (plansIter.hasNext()) { |
| p = plansIter.next(); |
| } |
| if (p == null) { |
| return false; |
| } |
| if (p.getRoots().size() != 1) { |
| return false; |
| } |
| Mutable<ILogicalOperator> op1Ref = p.getRoots().get(0); |
| AbstractLogicalOperator op1 = (AbstractLogicalOperator) op1Ref.getValue(); |
| boolean found = false; |
| while (op1.getInputs().size() == 1) { |
| if (op1.getOperatorTag() == LogicalOperatorTag.SUBPLAN) { |
| SubplanOperator subplan = (SubplanOperator) op1; |
| AbstractLogicalOperator op2 = (AbstractLogicalOperator) subplan.getInputs().get(0).getValue(); |
| if (OperatorPropertiesUtil.isNullTest(op2)) { |
| if (subplan.getNestedPlans().size() == 1) { |
| ILogicalPlan p1 = subplan.getNestedPlans().get(0); |
| if (p1.getRoots().size() == 1) { |
| AbstractLogicalOperator r1 = (AbstractLogicalOperator) p1.getRoots().get(0).getValue(); |
| if (r1.getOperatorTag() == LogicalOperatorTag.INNERJOIN |
| || r1.getOperatorTag() == LogicalOperatorTag.LEFTOUTERJOIN) { |
| // now, check that it propagates all variables, |
| // so it can be pushed |
| List<LogicalVariable> op2Vars = new ArrayList<LogicalVariable>(); |
| VariableUtilities.getLiveVariables(op2, op2Vars); |
| List<LogicalVariable> op1Vars = new ArrayList<LogicalVariable>(); |
| VariableUtilities.getLiveVariables(subplan, op1Vars); |
| if (op1Vars.containsAll(op2Vars)) { |
| found = true; |
| break; |
| } |
| } |
| } |
| } |
| } |
| } |
| op1Ref = op1.getInputs().get(0); |
| op1 = (AbstractLogicalOperator) op1Ref.getValue(); |
| } |
| if (!found) { |
| return false; |
| } |
| |
| ILogicalOperator subplan = op1; |
| ILogicalOperator op2 = op1.getInputs().get(0).getValue(); |
| op1Ref.setValue(op2); |
| Mutable<ILogicalOperator> opUnderRef = gby.getInputs().get(0); |
| ILogicalOperator opUnder = opUnderRef.getValue(); |
| subplan.getInputs().clear(); |
| subplan.getInputs().add(new MutableObject<ILogicalOperator>(opUnder)); |
| opUnderRef.setValue(subplan); |
| |
| return true; |
| } |
| } |