dwsmith1983 commented on code in PR #6785: URL: https://github.com/apache/datafusion-comet/pull/6785#discussion_r4233303896
########## spark/src/main/scala/org/apache/comet/rules/CometShuffledHashJoinStrategy.scala: ########## @@ -0,0 +1,194 @@ +/* + * 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.{BROADCAST, Join, JoinHint, LogicalPlan, SHUFFLE_HASH, SHUFFLE_MERGE, SHUFFLE_REPLICATE_NL} +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( + leftKeys, + rightKeys, + joinType, + side, + condition, + planLater(left), + planLater(right))) + } + case None => Nil + } + case _ => Nil + } + + // Broadcasts, including the ones AQE plans once a stage turns out small, and joins with a + // strategy hint are planned by Spark as usual. + private def isLeftToSpark(join: Join, hint: JoinHint): Boolean = + isBroadcastStage(join.left) || isBroadcastStage(join.right) || + canPlanAsBroadcastHashJoin(join, sqlConf) || hasStrategyHint(hint) + + private def isBroadcastStage(plan: LogicalPlan): Boolean = plan match { + case LogicalQueryStage(_, _: BroadcastQueryStageExec) => true + case _ => false + } + + // AQE's own hints, such as NO_BROADCAST_HASH and PREFER_SHUFFLE_HASH, do not count. + private def hasStrategyHint(hint: JoinHint): Boolean = + Seq(hint.leftHint, hint.rightHint).flatten.flatMap(_.strategy).exists { + case BROADCAST | SHUFFLE_MERGE | SHUFFLE_HASH | SHUFFLE_REPLICATE_NL => true + case _ => false Review Comment: > Could `hasStrategyHint` use it Done. It now checks `JoinStrategyHint.strategies`, so the four constant imports and the match are gone. I also added a test that a side AQE marks `NO_BROADCAST_HASH` keeps the hash join, since that hint is outside the set and nothing covered it. -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
