maropu commented on a change in pull request #23750: [SPARK-19712][SQL] Pushing Left Semi and Left Anti joins through Project, Aggregate, Window, Union etc. URL: https://github.com/apache/spark/pull/23750#discussion_r257530553
########## File path: sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/PushDownLeftSemiAntiJoin.scala ########## @@ -0,0 +1,197 @@ +/* + * 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.spark.sql.catalyst.optimizer + +import org.apache.spark.sql.catalyst.expressions._ +import org.apache.spark.sql.catalyst.expressions.aggregate.{AggregateExpression, AggregateFunction, Complete} +import org.apache.spark.sql.catalyst.plans.LeftSemiOrAnti +import org.apache.spark.sql.catalyst.plans.logical._ +import org.apache.spark.sql.catalyst.rules.Rule + +/** + * Pushes Left semi and Left Anti joins below the following operators. + * 1) Project + * 2) Window + * 3) Union + * 4) Aggregate + * 5) Other permissible unary operators. please see [[PushDownPredicate.canPushThrough]]. + */ + +object PushDownLeftSemiAntiJoin extends Rule[LogicalPlan] with PredicateHelper { + def apply(plan: LogicalPlan): LogicalPlan = plan transform { + // Similar to the above Filter over Project + // LeftSemi/LeftAnti over Project + case Join(p @ Project(pList, gChild), rightOp, LeftSemiOrAnti(joinType), joinCond, hint) + if pList.forall(_.deterministic) && + !pList.find(ScalarSubquery.hasScalarSubquery(_)).isDefined && + canPushThroughCondition(Seq(gChild), joinCond, rightOp) => + if (joinCond.isEmpty) { + // No join condition, just push down the Join below Project + p.copy(child = Join(gChild, rightOp, joinType, joinCond, hint)) + } else { + val aliasMap = PushDownPredicate.getAliasMap(p) + val newJoinCond = if (aliasMap.nonEmpty) { + Option(replaceAlias(joinCond.get, aliasMap)) + } else { + joinCond + } + p.copy(child = Join(gChild, rightOp, joinType, newJoinCond, hint)) + } + + // Similar to the above Filter over Aggregate + // LeftSemi/LeftAnti over Aggregate + case join @ Join(agg: Aggregate, rightOp, LeftSemiOrAnti(joinType), joinCond, hint) + if agg.aggregateExpressions.forall(_.deterministic) + && agg.groupingExpressions.nonEmpty => + if (joinCond.isEmpty) { + // No join condition, just push down Join below Aggregate + agg.copy(child = Join(agg.child, rightOp, joinType, joinCond, hint)) + } else { + val aliasMap = PushDownPredicate.getAliasMap(agg) + + // For each join condition, expand the alias and + // check if the condition can be evaluated using + // attributes produced by the aggregate operator's child operator. + val (pushDown, stayUp) = splitConjunctivePredicates(joinCond.get).partition { cond => + val replaced = replaceAlias(cond, aliasMap) + cond.references.nonEmpty && Review comment: oh, I see. Thanks! ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
