dwsmith1983 commented on code in PR #6785: URL: https://github.com/apache/datafusion-comet/pull/6785#discussion_r4322322761
########## spark/src/main/scala/org/apache/comet/rules/CometShuffledHashJoinStrategy.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.comet.rules + +import org.apache.spark.sql.SparkSession +import org.apache.spark.sql.catalyst.expressions.RowOrdering +import org.apache.spark.sql.catalyst.optimizer.{BuildLeft, BuildRight, BuildSide} +import org.apache.spark.sql.catalyst.planning.ExtractEquiJoinKeys +import org.apache.spark.sql.catalyst.plans.{ExistenceJoin, LeftSemi} +import org.apache.spark.sql.catalyst.plans.logical.{Join, JoinHint, JoinStrategyHint, LogicalPlan} +import org.apache.spark.sql.execution.{SparkPlan, SparkStrategy} +import org.apache.spark.sql.execution.adaptive.{BroadcastQueryStageExec, LogicalQueryStage} +import org.apache.spark.sql.execution.joins.{ShuffledHashJoinExec, SortMergeJoinExec} +import org.apache.spark.sql.internal.SQLConf + +import org.apache.comet.CometConf +import org.apache.comet.CometSparkSessionExtensions.{isCometLoaded, withFallbackReason, withInfo} +import org.apache.comet.shims.ShimJoinSelection + +/** + * Plans an equi-join as a ShuffledHashJoinExec where Spark would plan a SortMergeJoinExec, when + * spark.comet.exec.forceShuffledHashJoin is on. Choosing the join here, before EnsureRequirements + * and RemoveRedundantSorts run, lets Spark place and keep every sort the plan needs above the + * join. Planner strategies also run again on every AQE re-plan, where the join's children carry + * the materialized shuffle sizes. + * + * Adapted from the equivalent rule in Apache Gluten. + */ +case class CometShuffledHashJoinStrategy(session: SparkSession) + extends SparkStrategy + with ShimJoinSelection { + + override def apply(plan: LogicalPlan): Seq[SparkPlan] = plan match { + case join: Join if isEnabled(join) => planJoin(join) + case _ => Nil + } + + private def sqlConf: SQLConf = session.sessionState.conf + + // Planner strategies run whether or not Comet is enabled, and before CometRule, so plan-only + // mode needs its own check here. + private def isEnabled(join: Join): Boolean = + CometConf.COMET_FORCE_SHJ.get(sqlConf) && + CometConf.COMET_EXEC_ENABLED.get(sqlConf) && + !CometConf.COMET_EXPLAIN_PLAN_ONLY_ENABLED.get(sqlConf) && + !join.isStreaming && + isCometLoaded(sqlConf) + + private def planJoin(join: Join): Seq[SparkPlan] = join match { + case ExtractEquiJoinKeys(joinType, leftKeys, rightKeys, condition, _, left, right, hint) + if !isLeftToSpark(join, hint) && canSortMergeJoin(joinType) && + RowOrdering.isOrderable(leftKeys) && hashJoinSupportedShim(leftKeys, rightKeys) => + buildSide(join) match { + case Some(BuildRight) if joinType == LeftSemi || joinType.isInstanceOf[ExistenceJoin] => + // LeftSemi https://github.com/apache/datafusion-comet/issues/2667 + // ExistenceJoin https://github.com/apache/datafusion-comet/issues/2697 + planBySpark(join) { smj => + withFallbackReason(smj, declineReason(s"BuildRight with $joinType is not supported")) + } + case Some(side) => + buildSideOverLimit(join, side) match { + case Some(reason) => + // The sort-merge join still runs natively, so this is information for extended + // explain rather than a fallback reason. + planBySpark(join)(smj => withInfo(smj, declineReason(reason))) + case None => + Seq( + ShuffledHashJoinExec( Review Comment: Confirmed. It isn't specific to the forced join: on main, a `SHUFFLE_HASH` or `BROADCAST` hint over the same `localCheckpoint` probe loses the order the same way, for both outer shapes and both hash join kinds. It's the second shape of #6922. The fix goes to main first. When the streamed order can't be checked and reaches the join through an input from the JVM (a checkpoint or a cache) or through a nested loop join, the outer hash join falls back to Spark. Joins over native operators in the same plan stay native, since DataFusion sees the order there. Once that lands I'll merge it here and add the forced checkpoint case. -- 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. 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