peter-toth commented on code in PR #42223: URL: https://github.com/apache/spark/pull/42223#discussion_r1283035781
########## sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/CombineJoinedAggregates.scala: ########## @@ -0,0 +1,132 @@ +/* + * 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 scala.collection.mutable.ArrayBuffer + +import org.apache.spark.sql.catalyst.expressions.{Alias, And, Attribute, AttributeMap, Expression, NamedExpression, Or} +import org.apache.spark.sql.catalyst.expressions.aggregate.AggregateExpression +import org.apache.spark.sql.catalyst.plans.{Cross, FullOuter, Inner, JoinType, LeftOuter, RightOuter} +import org.apache.spark.sql.catalyst.plans.logical.{Aggregate, Filter, Join, LeafNode, LogicalPlan, Project, SerializeFromObject} +import org.apache.spark.sql.catalyst.rules.Rule +import org.apache.spark.sql.catalyst.trees.TreePattern.{AGGREGATE, JOIN} + +/** + * This rule eliminates the [[Join]] if all the join side are [[Aggregate]]s by combine these + * [[Aggregate]]s. This rule also support the nested [[Join]], as long as all the join sides for + * every [[Join]] are [[Aggregate]]s. + * + * Note: this rule doesn't following cases: + * 1. One of the to be merged two [[Aggregate]]s with child [[Filter]] and the other one is not. Review Comment: > > disabled merge (to be on the safe side) if any filters are pushed down to scans as partitioning or bucketing filters > > The treatment looks too strict. For partition filters, as long as the number of data rows is not too large, it can still benefit. Sure, merging can be beneficial (partitions filters overlap or scan cost is not significant), but I wanted to be on the safe side with the PR. We can also lift that restriction later with a more sophisticated logic. > > allowed merge depending on a new spark.sql.planMerge.ignorePushedDataFilters > > The treatment looks too strict too. Even if the data filter cannot be pushed down, we can still achieve many benefits. If no filters are pushed down then merging is allowed, see 1st point. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org
