executor: fix hash join v2 bug that mistakenly think the join has other condition (#56834)

close #56825

Author: windtalker

pkg/executor/builder.go

@@ -1514,13 +1514,28 @@ func (b *executorBuilder) buildHashJoinV2(v *plannercore.PhysicalHashJoin) exec.
 		return nil
 	}
 
+	joinOtherCondition := v.OtherConditions
+	joinLeftCondition := v.LeftConditions
+	joinRightCondition := v.RightConditions
+	if len(joinOtherCondition) == 0 {
+		// sometimes the OtherCondtition could be a not nil slice with length = 0
+		// in HashJoinV2, it is assumed that if there is no other condition, e.HashJoinCtxV2.OtherCondition should be nil
+		joinOtherCondition = nil
+	}
+	if len(joinLeftCondition) == 0 {
+		joinLeftCondition = nil
+	}
+	if len(joinRightCondition) == 0 {
+		joinRightCondition = nil
+	}
+
 	e := &join.HashJoinV2Exec{
 		BaseExecutor:          exec.NewBaseExecutor(b.ctx, v.Schema(), v.ID(), leftExec, rightExec),
 		ProbeSideTupleFetcher: &join.ProbeSideTupleFetcherV2{},
 		ProbeWorkers:          make([]*join.ProbeWorkerV2, v.Concurrency),
 		BuildWorkers:          make([]*join.BuildWorkerV2, v.Concurrency),
 		HashJoinCtxV2: &join.HashJoinCtxV2{
-			OtherCondition: v.OtherConditions,
+			OtherCondition: joinOtherCondition,
 		},
 	}
 	e.HashJoinCtxV2.SessCtx = b.ctx
@@ -1541,12 +1556,12 @@ func (b *executorBuilder) buildHashJoinV2(v *plannercore.PhysicalHashJoin) exec.
 	joinedTypes = append(joinedTypes, rhsTypes...)
 
 	if v.InnerChildIdx == 1 {
-		if len(v.RightConditions) > 0 {
+		if joinRightCondition != nil {
 			b.err = errors.Annotate(exeerrors.ErrBuildExecutor, "join's inner condition should be empty")
 			return nil
 		}
 	} else {
-		if len(v.LeftConditions) > 0 {
+		if joinLeftCondition != nil {
 			b.err = errors.Annotate(exeerrors.ErrBuildExecutor, "join's inner condition should be empty")
 			return nil
 		}
@@ -1558,21 +1573,21 @@ func (b *executorBuilder) buildHashJoinV2(v *plannercore.PhysicalHashJoin) exec.
 		if v.InnerChildIdx == 1 {
 			buildSideExec, buildKeys = leftExec, v.LeftJoinKeys
 			e.ProbeSideTupleFetcher.ProbeSideExec, probeKeys = rightExec, v.RightJoinKeys
-			e.HashJoinCtxV2.BuildFilter = v.LeftConditions
+			e.HashJoinCtxV2.BuildFilter = joinLeftCondition
 		} else {
 			buildSideExec, buildKeys = rightExec, v.RightJoinKeys
 			e.ProbeSideTupleFetcher.ProbeSideExec, probeKeys = leftExec, v.LeftJoinKeys
-			e.HashJoinCtxV2.BuildFilter = v.RightConditions
+			e.HashJoinCtxV2.BuildFilter = joinRightCondition
 		}
 	} else {
 		if v.InnerChildIdx == 0 {
 			buildSideExec, buildKeys = leftExec, v.LeftJoinKeys
 			e.ProbeSideTupleFetcher.ProbeSideExec, probeKeys = rightExec, v.RightJoinKeys
-			e.HashJoinCtxV2.ProbeFilter = v.RightConditions
+			e.HashJoinCtxV2.ProbeFilter = joinRightCondition
 		} else {
 			buildSideExec, buildKeys = rightExec, v.RightJoinKeys
 			e.ProbeSideTupleFetcher.ProbeSideExec, probeKeys = leftExec, v.LeftJoinKeys
-			e.HashJoinCtxV2.ProbeFilter = v.LeftConditions
+			e.HashJoinCtxV2.ProbeFilter = joinLeftCondition
 		}
 	}
 	probeKeyColIdx := make([]int, len(probeKeys))
@@ -1598,9 +1613,9 @@ func (b *executorBuilder) buildHashJoinV2(v *plannercore.PhysicalHashJoin) exec.
 	e.LUsed = append(e.LUsed, childrenUsedSchema[0]...)
 	e.RUsed = make([]int, 0, len(childrenUsedSchema[1]))
 	e.RUsed = append(e.RUsed, childrenUsedSchema[1]...)
-	if v.OtherConditions != nil {
+	if joinOtherCondition != nil {
 		leftColumnSize := v.Children()[0].Schema().Len()
-		e.LUsedInOtherCondition, e.RUsedInOtherCondition = extractUsedColumnsInJoinOtherCondition(v.OtherConditions, leftColumnSize)
+		e.LUsedInOtherCondition, e.RUsedInOtherCondition = extractUsedColumnsInJoinOtherCondition(joinOtherCondition, leftColumnSize)
 	}
 	// todo add partition hash join exec
 	executor_metrics.ExecutorCountHashJoinExec.Inc()