| /* |
| * 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.drill.exec.planner.physical; |
| |
| import java.util.List; |
| |
| import org.apache.calcite.plan.RelOptRule; |
| import org.apache.calcite.plan.RelOptRuleCall; |
| import org.apache.calcite.plan.RelTraitSet; |
| import org.apache.calcite.rel.InvalidRelException; |
| import org.apache.calcite.rel.RelNode; |
| import org.apache.calcite.rel.type.RelDataTypeField; |
| import org.apache.calcite.util.trace.CalciteTrace; |
| import org.apache.drill.exec.planner.logical.DrillUnionRel; |
| import org.apache.drill.exec.planner.logical.RelOptHelper; |
| import org.apache.drill.exec.planner.physical.DrillDistributionTrait.DistributionField; |
| |
| import org.apache.drill.shaded.guava.com.google.common.base.Preconditions; |
| import org.apache.drill.shaded.guava.com.google.common.collect.ImmutableList; |
| import org.apache.drill.shaded.guava.com.google.common.collect.Lists; |
| import org.slf4j.Logger; |
| |
| public class UnionAllPrule extends Prule { |
| public static final RelOptRule INSTANCE = new UnionAllPrule(); |
| protected static final Logger tracer = CalciteTrace.getPlannerTracer(); |
| |
| private UnionAllPrule() { |
| super(RelOptHelper.any(DrillUnionRel.class), "Prel.UnionAllPrule"); |
| } |
| |
| @Override |
| public boolean matches(RelOptRuleCall call) { |
| DrillUnionRel union = call.rel(0); |
| return (! union.isDistinct()); |
| } |
| |
| @Override |
| public void onMatch(RelOptRuleCall call) { |
| final DrillUnionRel union = call.rel(0); |
| final List<RelNode> inputs = union.getInputs(); |
| List<RelNode> convertedInputList = Lists.newArrayList(); |
| PlannerSettings settings = PrelUtil.getPlannerSettings(call.getPlanner()); |
| boolean allHashDistributed = true; |
| |
| for (RelNode child : inputs) { |
| List<DistributionField> childDistFields = Lists.newArrayList(); |
| RelNode convertedChild; |
| |
| for (RelDataTypeField f : child.getRowType().getFieldList()) { |
| childDistFields.add(new DistributionField(f.getIndex())); |
| } |
| |
| if (settings.isUnionAllDistributeEnabled()) { |
| /* |
| * Strictly speaking, union-all does not need re-distribution of data; but in Drill's execution |
| * model, the data distribution and parallelism operators are the same. Here, we insert a |
| * hash distribution operator to allow parallelism to be determined independently for the parent |
| * and children. (See DRILL-4833). |
| * Note that a round robin distribution would have sufficed but we don't have one. |
| */ |
| DrillDistributionTrait hashChild = new DrillDistributionTrait(DrillDistributionTrait.DistributionType.HASH_DISTRIBUTED, ImmutableList.copyOf(childDistFields)); |
| RelTraitSet traitsChild = call.getPlanner().emptyTraitSet().plus(Prel.DRILL_PHYSICAL).plus(hashChild); |
| convertedChild = convert(child, PrelUtil.fixTraits(call, traitsChild)); |
| } else { |
| RelTraitSet traitsChild = call.getPlanner().emptyTraitSet().plus(Prel.DRILL_PHYSICAL); |
| convertedChild = convert(child, PrelUtil.fixTraits(call, traitsChild)); |
| allHashDistributed = false; |
| } |
| convertedInputList.add(convertedChild); |
| } |
| |
| try { |
| |
| RelTraitSet traits; |
| if (allHashDistributed) { |
| // since all children of union-all are hash distributed, propagate the traits of the left child |
| traits = convertedInputList.get(0).getTraitSet(); |
| } else { |
| // output distribution trait is set to ANY since union-all inputs may be distributed in different ways |
| // and unlike a join there are no join keys that allow determining how the output would be distributed. |
| // Note that a downstream operator may impose a required distribution which would be satisfied by |
| // inserting an Exchange after the Union-All. |
| traits = call.getPlanner().emptyTraitSet().plus(Prel.DRILL_PHYSICAL).plus(DrillDistributionTrait.ANY); |
| } |
| |
| Preconditions.checkArgument(convertedInputList.size() >= 2, "Union list must be at least two items."); |
| RelNode left = convertedInputList.get(0); |
| for (int i = 1; i < convertedInputList.size(); i++) { |
| left = new UnionAllPrel(union.getCluster(), traits, ImmutableList.of(left, convertedInputList.get(i))); |
| |
| } |
| call.transformTo(left); |
| |
| } catch (InvalidRelException e) { |
| tracer.warn(e.toString()); |
| } |
| } |
| |
| } |