| /** |
| * 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 java.util.logging.Logger; |
| |
| 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.util.trace.CalciteTrace; |
| import org.apache.drill.exec.planner.logical.DrillUnionRel; |
| import org.apache.drill.exec.planner.logical.RelOptHelper; |
| |
| import com.google.common.base.Preconditions; |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.collect.Lists; |
| |
| 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 = (DrillUnionRel) call.rel(0); |
| return (! union.isDistinct()); |
| } |
| |
| @Override |
| public void onMatch(RelOptRuleCall call) { |
| final DrillUnionRel union = (DrillUnionRel) call.rel(0); |
| final List<RelNode> inputs = union.getInputs(); |
| List<RelNode> convertedInputList = Lists.newArrayList(); |
| RelTraitSet traits = call.getPlanner().emptyTraitSet().plus(Prel.DRILL_PHYSICAL); |
| |
| try { |
| for (int i = 0; i < inputs.size(); i++) { |
| RelNode convertedInput = convert(inputs.get(i), PrelUtil.fixTraits(call, traits)); |
| convertedInputList.add(convertedInput); |
| } |
| |
| // 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)), |
| false /* compatibility already checked during logical phase */); |
| |
| } |
| call.transformTo(left); |
| |
| } catch (InvalidRelException e) { |
| tracer.warning(e.toString()); |
| } |
| } |
| |
| } |