rubenada commented on a change in pull request #1369: [CALCITE-2979] Add a block-based nested loop join algorithm (Khawla Mouhoubi) URL: https://github.com/apache/calcite/pull/1369#discussion_r315063887
########## File path: core/src/main/java/org/apache/calcite/adapter/enumerable/EnumerableBatchNestedLoopJoin.java ########## @@ -0,0 +1,252 @@ +/* + * 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.calcite.adapter.enumerable; + +import org.apache.calcite.linq4j.function.Predicate2; +import org.apache.calcite.linq4j.tree.BlockBuilder; +import org.apache.calcite.linq4j.tree.DeclarationStatement; +import org.apache.calcite.linq4j.tree.Expression; +import org.apache.calcite.linq4j.tree.Expressions; +import org.apache.calcite.linq4j.tree.ParameterExpression; +import org.apache.calcite.linq4j.tree.Primitive; +import org.apache.calcite.plan.RelOptCluster; +import org.apache.calcite.plan.RelOptCost; +import org.apache.calcite.plan.RelOptPlanner; +import org.apache.calcite.plan.RelTraitSet; +import org.apache.calcite.rel.RelCollationTraitDef; +import org.apache.calcite.rel.RelNode; +import org.apache.calcite.rel.RelWriter; +import org.apache.calcite.rel.core.CorrelationId; +import org.apache.calcite.rel.core.Join; +import org.apache.calcite.rel.core.JoinRelType; +import org.apache.calcite.rel.metadata.RelMdCollation; +import org.apache.calcite.rel.metadata.RelMetadataQuery; +import org.apache.calcite.rex.RexNode; +import org.apache.calcite.rex.RexProgramBuilder; +import org.apache.calcite.util.BuiltInMethod; +import org.apache.calcite.util.ImmutableBitSet; +import org.apache.calcite.util.Pair; + +import com.google.common.collect.ImmutableList; + +import java.lang.reflect.Modifier; +import java.lang.reflect.Type; +import java.util.ArrayList; +import java.util.List; +import java.util.Set; + +/** Implementation of {@link org.apache.calcite.rel.core.Join} in + * {@link org.apache.calcite.adapter.enumerable.EnumerableConvention enumerable calling convention}. */ +public class EnumerableBatchNestedLoopJoin extends Join implements EnumerableRel { + + private final ImmutableBitSet requiredColumns; + protected EnumerableBatchNestedLoopJoin( + RelOptCluster cluster, + RelTraitSet traits, + RelNode left, + RelNode right, + RexNode condition, + Set<CorrelationId> variablesSet, + ImmutableBitSet requiredColumns, + JoinRelType joinType) { + super(cluster, traits, left, right, condition, variablesSet, joinType); + this.requiredColumns = requiredColumns; + } + + public static EnumerableBatchNestedLoopJoin create( + RelNode left, + RelNode right, + RexNode condition, + ImmutableBitSet requiredColumns, + Set<CorrelationId> variablesSet, + JoinRelType joinType) { + final RelOptCluster cluster = left.getCluster(); + final RelMetadataQuery mq = cluster.getMetadataQuery(); + final RelTraitSet traitSet = + cluster.traitSetOf(EnumerableConvention.INSTANCE) + .replaceIfs(RelCollationTraitDef.INSTANCE, + () -> RelMdCollation.enumerableBatchNestedLoopJoin(mq, left, right, joinType)); + return new EnumerableBatchNestedLoopJoin( + cluster, + traitSet, + left, + right, + condition, + variablesSet, + requiredColumns, + joinType); + } + + @Override public EnumerableBatchNestedLoopJoin copy(RelTraitSet traitSet, + RexNode condition, RelNode left, RelNode right, JoinRelType joinType, + boolean semiJoinDone) { + return new EnumerableBatchNestedLoopJoin(getCluster(), traitSet, + left, right, condition, variablesSet, requiredColumns, joinType); + } + + @Override public RelOptCost computeSelfCost( + final RelOptPlanner planner, + final RelMetadataQuery mq) { + double rowCount = mq.getRowCount(this); + + final double rightRowCount = right.estimateRowCount(mq); + final double leftRowCount = left.estimateRowCount(mq); + if (Double.isInfinite(leftRowCount) || Double.isInfinite(rightRowCount)) { + return planner.getCostFactory().makeInfiniteCost(); + } + + Double restartCount = mq.getRowCount(getLeft()) / variablesSet.size(); + + RelOptCost rightCost = planner.getCost(getRight(), mq); + RelOptCost rescanCost = + rightCost.multiplyBy(Math.max(1.0, restartCount - 1)); + + // TODO Add cost of last loop (the one that looks for the match) + return planner.getCostFactory().makeCost( + rowCount + leftRowCount, 0, 0).plus(rescanCost); + } + + @Override public RelWriter explainTerms(RelWriter pw) { + super.explainTerms(pw); + return pw.item("batchSize", variablesSet.size()); + } + + public Result implement(EnumerableRelImplementor implementor, Prefer pref) { + final BlockBuilder builder = new BlockBuilder(); + final Result leftResult = + implementor.visitChild(this, 0, (EnumerableRel) left, pref); + Expression leftExpression = + builder.append( + "left", leftResult.block); + + List<String> corrVar = new ArrayList<>(); + for (CorrelationId c : variablesSet) { + corrVar.add(c.getName()); + } + + final BlockBuilder corrBlock = new BlockBuilder(); + Type corrVarType = leftResult.physType.getJavaRowType(); + ParameterExpression corrArg; + ParameterExpression corrArgList = + Expressions.parameter(Modifier.FINAL, + List.class, "corrList"); + + // Declare batchSize correlation variables + if (!Primitive.is(corrVarType)) { + for (int c = 0; c < corrVar.size(); c++) { + corrArg = + Expressions.parameter(Modifier.FINAL, + corrVarType, corrVar.get(c)); + DeclarationStatement decl = Expressions.declare( + Modifier.FINAL, + corrArg, + Expressions.convert_( + Expressions.call( + corrArgList, + BuiltInMethod.LIST_GET.method, + Expressions.constant(c)), + corrVarType)); + corrBlock.add(decl); + implementor.registerCorrelVariable(corrVar.get(c), corrArg, + corrBlock, leftResult.physType); + } + } else { + for (int c = 0; c < corrVar.size(); c++) { + corrArg = + Expressions.parameter(Modifier.FINAL, + Primitive.box(corrVarType), "$box" + corrVar.get(c)); + DeclarationStatement decl = Expressions.declare( + Modifier.FINAL, + corrArg, + Expressions.call( + corrArgList, + BuiltInMethod.LIST_GET.method, + Expressions.constant(c))); + corrBlock.add(decl); + ParameterExpression corrRef = + (ParameterExpression) corrBlock.append(corrVar.get(c), + Expressions.unbox(corrArg)); + implementor.registerCorrelVariable(corrVar.get(c), corrRef, + corrBlock, leftResult.physType); + } + } + final Result rightResult = + implementor.visitChild(this, 1, (EnumerableRel) right, pref); + + corrBlock.add(rightResult.block); + for (String c : corrVar) { + implementor.clearCorrelVariable(c); + } + + final PhysType physType = + PhysTypeImpl.of( + implementor.getTypeFactory(), + getRowType(), + pref.prefer(JavaRowFormat.CUSTOM)); + Expression selector = + EnumUtils.joinSelector( + joinType, physType, + ImmutableList.of(leftResult.physType, rightResult.physType)); + + final BlockBuilder builderPredicate = new BlockBuilder(); + Expression predicate = predicate(implementor, + builderPredicate, + leftResult.physType, + rightResult.physType); + + builder.append( + Expressions.call(BuiltInMethod.CORRELATE_BATCH_JOIN.method, + Expressions.constant(EnumUtils.toLinq4jJoinType(joinType)), + leftExpression, + Expressions.lambda(corrBlock.toBlock(), corrArgList), + selector, + predicate, + Expressions.constant(variablesSet.size()))); + return implementor.result(physType, builder.toBlock()); + } + + // Predicate "matches" that is gonna be used in correlateBatchJoin to compare two tuples Review comment: Thanks for the correction, but preposition "to" is still missing in the comment. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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