agrawaldevesh commented on a change in pull request #29104: URL: https://github.com/apache/spark/pull/29104#discussion_r458273917
########## File path: sql/core/src/main/scala/org/apache/spark/sql/execution/joins/BroadcastNullAwareHashJoinExec.scala ########## @@ -0,0 +1,205 @@ +/* + * 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.joins + +import org.apache.spark.rdd.RDD +import org.apache.spark.sql.catalyst.InternalRow +import org.apache.spark.sql.catalyst.expressions._ +import org.apache.spark.sql.catalyst.expressions.codegen.{CodegenContext, ExprCode, GenerateUnsafeProjection} +import org.apache.spark.sql.catalyst.optimizer.{BuildRight, BuildSide} +import org.apache.spark.sql.catalyst.plans._ +import org.apache.spark.sql.catalyst.plans.physical._ +import org.apache.spark.sql.execution.{CodegenSupport, ExplainUtils, SparkPlan} +import org.apache.spark.sql.execution.metric.SQLMetrics +import org.apache.spark.sql.internal.SQLConf +import org.apache.spark.sql.types.LongType + +case class BroadcastNullAwareHashJoinExec( + leftKeys: Seq[Expression], + rightKeys: Seq[Expression], + left: SparkPlan, + right: SparkPlan, + buildSide: BuildSide, + joinType: JoinType, + condition: Option[Expression]) extends BaseJoinExec with CodegenSupport { + + // TODO support multi column NULL-aware anti join in future. + // See. http://www.vldb.org/pvldb/vol2/vldb09-423.pdf Section 6 + // multi-column null aware anti join is much more complicated than single column ones. + require(leftKeys.length == 1, "leftKeys length should be 1") + require(rightKeys.length == 1, "rightKeys length should be 1") + require(right.output.length == 1, "null aware anti join only supports single column.") + require(joinType == LeftAnti, "joinType must be LeftAnti.") + require(buildSide == BuildRight, "buildSide must be BuildRight.") + require(SQLConf.get.nullAwareAntiJoinOptimizeEnabled, + "nullAwareAntiJoinOptimizeEnabled must be on for null aware anti join optimize.") + + override lazy val metrics = Map( + "numOutputRows" -> SQLMetrics.createMetric(sparkContext, "number of output rows")) + + private val (streamed, broadcast) = (left, right) + + override def simpleStringWithNodeId(): String = { + val opId = ExplainUtils.getOpId(this) + s"$nodeName $joinType ${buildSide} ($opId)".trim + } + + override def requiredChildDistribution: Seq[Distribution] = { + UnspecifiedDistribution :: BroadcastDistribution(IdentityBroadcastMode) :: Nil + } + + private[this] def genResultProjection: UnsafeProjection = { + UnsafeProjection.create(output, output) + } + + override def output: Seq[Attribute] = { + left.output + } + + private def prepareBroadcastHashedRelation = { + val buildSideRows = broadcast.executeBroadcast[Array[InternalRow]]().value + HashedRelation(buildSideRows.iterator, + BindReferences.bindReferences[Expression]( + Seq(right.output.head), AttributeSeq(right.output)), + buildSideRows.length) + } + + private def nullAwareLeftAntiJoin( + relation: HashedRelation): RDD[InternalRow] = { + streamed.execute().mapPartitionsInternal { streamedIter => + if (relation.inputEmpty) { + streamedIter + } else if (relation.anyNullKeyExists) { + Iterator.empty + } else { + val keyGenerator = UnsafeProjection.create( + BindReferences.bindReferences[Expression]( + leftKeys, + AttributeSeq(left.output)) + ) + streamedIter.filter(row => { + val lookupKey: UnsafeRow = keyGenerator(row) + val streamedRowIsNull = lookupKey.isNullAt(0) + val notInKeyEqual = relation.get(lookupKey) != null + !streamedRowIsNull && !notInKeyEqual + }) + } + } + } + + protected override def doExecute(): RDD[InternalRow] = { + val relation: HashedRelation = prepareBroadcastHashedRelation + val resultRdd = (joinType, buildSide) match { + case (LeftAnti, BuildRight) => + nullAwareLeftAntiJoin(relation) + case _ => + throw new IllegalArgumentException( + s"BroadcastNullAwareHashJoinExec only supports (LeftAnti + BuildRight) for now.") + } + + val numOutputRows = longMetric("numOutputRows") + resultRdd.mapPartitionsWithIndexInternal { (index, iter) => + val resultProj = genResultProjection + resultProj.initialize(index) + iter.map { r => + numOutputRows += 1 + resultProj(r) + } + } + } + + override def needCopyResult: Boolean = + streamed.asInstanceOf[CodegenSupport].needCopyResult + + override def inputRDDs(): Seq[RDD[InternalRow]] = { + streamed.asInstanceOf[CodegenSupport].inputRDDs() + } + + override def doProduce(ctx: CodegenContext): String = { + streamed.asInstanceOf[CodegenSupport].produce(ctx, this) + } + + private def genStreamSideJoinKey( + ctx: CodegenContext, + input: Seq[ExprCode]): (ExprCode, String) = { + ctx.currentVars = input + if (leftKeys.length == 1 && leftKeys.head.dataType == LongType) { + // generate the join key as Long + val ev = + BindReferences.bindReference[Expression](leftKeys.head, left.output).genCode(ctx) + (ev, ev.isNull) + } else { + // generate the join key as UnsafeRow + val ev = GenerateUnsafeProjection.createCode(ctx, + BindReferences.bindReferences[Expression](leftKeys, left.output)) + (ev, s"${ev.value}.anyNull()") + } + } + + override def doConsume(ctx: CodegenContext, input: Seq[ExprCode], row: ExprCode): String = { + val relation: HashedRelation = prepareBroadcastHashedRelation + val broadcastRef = ctx.addReferenceObj("broadcast", relation) + val clsName = relation.getClass.getName + + // Inline mutable state since not many join operations in a task + val relationTerm = ctx.addMutableState(clsName, "relation", + v => s""" + | $v = (($clsName) $broadcastRef).asReadOnlyCopy(); + | incPeakExecutionMemory($v.estimatedSize()); + """.stripMargin, forceInline = true) + + val (keyEv, anyNull) = genStreamSideJoinKey(ctx, input) + val matched = ctx.freshName("matched") + val numOutput = metricTerm(ctx, "numOutputRows") + val found = ctx.freshName("found") + + if (relation.inputEmpty) { + s""" + |// singleColumn NAAJ inputEmpty(true) accept all + |$numOutput.add(1); + |${consume(ctx, input)} + """.stripMargin + } else if (relation.anyNullKeyExists) { + s""" + |// singleColumn NAAJ inputEmpty(false) anyNullKeyExists(true) reject all + """.stripMargin + } else { + s""" + |// singleColumn NAAJ inputEmpty(false) anyNullKeyExists(false) + |boolean $found = false; + |// generate join key for stream side + |${keyEv.code} + |// Check if the key has nulls. + |if (!($anyNull)) { + | // Check if the HashedRelation exists. + | UnsafeRow $matched = (UnsafeRow)$relationTerm.getValue(${keyEv.value}); Review comment: So the unique key code path optimization of BHJ isn't relevant here ? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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