bmarcott commented on a change in pull request #27096: [SPARK-28148][SQL] Repartition after join is not optimized away URL: https://github.com/apache/spark/pull/27096#discussion_r383072866
########## File path: sql/core/src/main/scala/org/apache/spark/sql/execution/exchange/PruneShuffleAndSort.scala ########## @@ -0,0 +1,52 @@ +/* + * 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.execution.exchange + +import org.apache.spark.sql.catalyst.expressions.SortOrder +import org.apache.spark.sql.catalyst.plans.physical.{HashPartitioning, PartitioningCollection} +import org.apache.spark.sql.catalyst.rules.Rule +import org.apache.spark.sql.execution.{SortExec, SparkPlan} + +/** + * Removes unnecessary shuffles and sorts after new ones are introduced by [[Rule]]s for + * [[SparkPlan]]s, such as [[EnsureRequirements]]. + */ +case class PruneShuffleAndSort() extends Rule[SparkPlan] { + + override def apply(plan: SparkPlan): SparkPlan = { + plan.transformUp { + case operator @ ShuffleExchangeExec(upper: HashPartitioning, child, _) => + child.outputPartitioning match { + case lower: HashPartitioning if upper.semanticEquals(lower) => child Review comment: @maryannxue This PR focused on fixing removing unnecessary sorting and shuffling after a join, which potentially includes its own ShuffleExchangeExec with HashPartioning. Both cases you mentioned are already optimized properly: the shuffling on "some_other_column" is removed and all sortWithinPartitions are removed (due to previous optimizations in logical plan, and the optimizations introduced here) I wouldn't mind generalizing to all Partitioning types of the ShuffleExchangeExec, but I am not sure how to compare two partitioning types for equality. You can see the special case for HashPartitioning in this PR. ---------------------------------------------------------------- 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. 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]
