ulysses-you commented on code in PR #57491:
URL: https://github.com/apache/spark/pull/57491#discussion_r3648282059
##########
sql/core/src/test/scala/org/apache/spark/sql/DataFrameSetOperationsSuite.scala:
##########
@@ -1659,6 +1659,187 @@ class DataFrameSetOperationsSuite extends
SharedSparkSession with AdaptiveSparkP
}
}
+ test("SPARK-58317: union partitioning - PartitioningCollection child
intersects to single") {
+ withSQLConf(
+ SQLConf.AUTO_BROADCASTJOIN_THRESHOLD.key -> "-1",
+ SQLConf.PREFER_SORTMERGEJOIN.key -> "false") {
+ withTempView("t1", "t2", "t3", "t4") {
+ Seq((1, 2, 4), (1, 3, 5), (2, 2, 3)).toDF("c1", "c2",
"c3").createOrReplaceTempView("t1")
+ Seq((1, 9), (2, 9)).toDF("c1", "x").createOrReplaceTempView("t2")
+ Seq((1, 2, 4), (2, 4, 5), (3, 6, 7)).toDF("c1", "c2",
"c3").createOrReplaceTempView("t3")
+ Seq((1, 9), (3, 9)).toDF("c1", "y").createOrReplaceTempView("t4")
+
+ // The first branch is an inner shuffled-hash join and selects both
join keys (t1.c1 and
+ // t2.c1), so its output partitioning is a
PartitioningCollection(Hash(c1), Hash(c1#..))
+ // that a downstream ProjectExec cannot narrow to a single member. The
second branch is a
+ // left join, whose output partitioning is a single
HashPartitioning(c1). The union should
+ // intersect the two to a single HashPartitioning(c1) and let the
group-by skip a shuffle.
+ def unionDF: DataFrame = sql(
+ """SELECT c1, c2, c3, count(*) FROM (
+ | SELECT /*+ SHUFFLE_HASH(t2) */ t1.c1, t1.c2, t1.c3, t2.c1 AS k
+ | FROM t1 JOIN t2 ON t1.c1 = t2.c1
+ | UNION ALL
+ | SELECT /*+ SHUFFLE_HASH(t4) */ t3.c1, t3.c2, t3.c3, t3.c1 AS k
+ | FROM t3 LEFT JOIN t4 ON t3.c1 = t4.c1
+ |) GROUP BY c1, c2, c3
+ |""".stripMargin)
+
+ val correctResult = withSQLConf(SQLConf.UNION_OUTPUT_PARTITIONING.key
-> "false") {
+ unionDF.collect()
+ }
+
+ val shuffleNums = Seq(true, false).map { enabled =>
+ withSQLConf(
+ SQLConf.ADAPTIVE_EXECUTION_ENABLED.key -> "false",
+ SQLConf.UNION_OUTPUT_PARTITIONING.key -> enabled.toString) {
+ val union = unionDF
+ val unionExec = union.queryExecution.executedPlan.collect { case
u: UnionExec => u }
+ assert(unionExec.size == 1)
+
+ val partitioning = unionExec.head.outputPartitioning
+ if (enabled) {
+ assert(partitioning.isInstanceOf[HashPartitioning],
+ s"expected a HashPartitioning pass-through but got
$partitioning")
+ } else {
+ assert(partitioning.isInstanceOf[UnknownPartitioning])
+ }
+
+ checkAnswer(union, correctResult)
+ union.queryExecution.executedPlan.collect {
+ case s: ShuffleExchangeExec => s
+ }.size
+ }
+ }
+ // Enabling the pass-through removes the shuffle before the aggregate.
+ assert(shuffleNums.head + 1 == shuffleNums.last)
+ }
+ }
+ }
+
+ test("SPARK-58317: union partitioning - all PartitioningCollection children
pass through") {
+ withSQLConf(
+ SQLConf.AUTO_BROADCASTJOIN_THRESHOLD.key -> "-1",
+ SQLConf.PREFER_SORTMERGEJOIN.key -> "false") {
+ withTempView("t1", "t2", "t3", "t4") {
+ Seq((1, 2), (2, 3)).toDF("c1", "c2").createOrReplaceTempView("t1")
+ Seq((1, 9), (2, 9)).toDF("c1", "x").createOrReplaceTempView("t2")
+ Seq((1, 2), (3, 4)).toDF("c1", "c2").createOrReplaceTempView("t3")
+ Seq((1, 9), (3, 9)).toDF("c1", "y").createOrReplaceTempView("t4")
+
+ // Both branches are inner shuffled-hash joins on a single key and
select both sides' join
+ // key (t1.c1 and t2.c1 AS k), so a downstream ProjectExec cannot
narrow either child's
+ // PartitioningCollection(Hash(c1), Hash(k)) to a single member. The
union should intersect
+ // to a PartitioningCollection carrying both members.
+ def unionDF: DataFrame = sql(
+ """SELECT /*+ SHUFFLE_HASH(t2) */ t1.c1, t2.c1 AS k
+ |FROM t1 JOIN t2 ON t1.c1 = t2.c1
+ |UNION ALL
+ |SELECT /*+ SHUFFLE_HASH(t4) */ t3.c1, t4.c1 AS k
+ |FROM t3 JOIN t4 ON t3.c1 = t4.c1
+ |""".stripMargin)
+
+ val correctResult = withSQLConf(SQLConf.UNION_OUTPUT_PARTITIONING.key
-> "false") {
+ unionDF.collect()
+ }
+
+ Seq(true, false).foreach { enabled =>
+ withSQLConf(
+ SQLConf.ADAPTIVE_EXECUTION_ENABLED.key -> "false",
+ SQLConf.UNION_OUTPUT_PARTITIONING.key -> enabled.toString) {
+ val union = unionDF
+ val unionExec = union.queryExecution.executedPlan.collect { case
u: UnionExec => u }
+ assert(unionExec.size == 1)
+
+ val partitioning = unionExec.head.outputPartitioning
+ if (enabled) {
+ assert(partitioning.isInstanceOf[PartitioningCollection],
+ s"expected a PartitioningCollection pass-through but got
$partitioning")
+ val members =
partitioning.asInstanceOf[PartitioningCollection].partitionings
+ assert(members.forall(_.isInstanceOf[HashPartitioning]))
+ assert(members.size == 2)
+ } else {
+ assert(partitioning.isInstanceOf[UnknownPartitioning])
+ }
+
+ checkAnswer(union, correctResult)
+ }
+ }
+ }
+ }
+ }
+
+ test("SPARK-58317: union partitioning - empty intersection falls back") {
+ withSQLConf(
+ SQLConf.AUTO_BROADCASTJOIN_THRESHOLD.key -> "-1",
+ SQLConf.PREFER_SORTMERGEJOIN.key -> "false") {
+ withTempView("t1", "t2") {
+ Seq((1, 2, 4), (2, 3, 5)).toDF("c1", "c2",
"c3").createOrReplaceTempView("t1")
+ Seq((1, 9), (2, 9)).toDF("c1", "x").createOrReplaceTempView("t2")
+
+ // First branch reports PartitioningCollection(Hash(c1), Hash(c1#..));
the second branch
+ // is repartitioned on a disjoint column, so the intersection is empty.
+ def unionDF: DataFrame = sql(
+ """SELECT /*+ SHUFFLE_HASH(t2) */ t1.c1, t1.c2, t1.c3, t2.c1 AS k
+ |FROM t1 JOIN t2 ON t1.c1 = t2.c1
+ |UNION ALL
+ |SELECT c1, c2, c3, c2 AS k FROM t1 DISTRIBUTE BY c2
+ |""".stripMargin)
+
+ val correctResult = withSQLConf(SQLConf.UNION_OUTPUT_PARTITIONING.key
-> "false") {
+ unionDF.collect()
+ }
+
+ Seq(true, false).foreach { enabled =>
+ withSQLConf(
+ SQLConf.ADAPTIVE_EXECUTION_ENABLED.key -> "false",
+ SQLConf.UNION_OUTPUT_PARTITIONING.key -> enabled.toString) {
+ val union = unionDF
+ val unionExec = union.queryExecution.executedPlan.collect { case
u: UnionExec => u }
+ assert(unionExec.size == 1)
+
assert(unionExec.head.outputPartitioning.isInstanceOf[UnknownPartitioning])
+ checkAnswer(union, correctResult)
+ }
+ }
+ }
+ }
+ }
+
+ test("SPARK-58317: union partitioning - PartitioningCollection pass-through
under AQE") {
+ // AQE is enabled by default in production; the collection pass-through
must produce correct
+ // results there too, where the union output flows through the
coalesce-compatibility path.
+ withSQLConf(
+ SQLConf.ADAPTIVE_EXECUTION_ENABLED.key -> "true",
+ SQLConf.AUTO_BROADCASTJOIN_THRESHOLD.key -> "-1",
+ SQLConf.PREFER_SORTMERGEJOIN.key -> "false") {
+ withTempView("t1", "t2", "t3", "t4") {
+ Seq((1, 2), (2, 3), (1, 4)).toDF("c1",
"c2").createOrReplaceTempView("t1")
+ Seq((1, 9), (2, 9)).toDF("c1", "x").createOrReplaceTempView("t2")
+ Seq((1, 2), (3, 4)).toDF("c1", "c2").createOrReplaceTempView("t3")
+ Seq((1, 9), (3, 9)).toDF("c1", "y").createOrReplaceTempView("t4")
+
+ def unionDF: DataFrame = sql(
+ """SELECT c1, count(*) FROM (
+ | SELECT /*+ SHUFFLE_HASH(t2) */ t1.c1, t2.c1 AS k
+ | FROM t1 JOIN t2 ON t1.c1 = t2.c1
+ | UNION ALL
+ | SELECT /*+ SHUFFLE_HASH(t4) */ t3.c1, t4.c1 AS k
+ | FROM t3 JOIN t4 ON t3.c1 = t4.c1
+ |) GROUP BY c1
Review Comment:
Applied in b79f1b2 -- `SELECT c1, k, ...` / `GROUP BY c1, k`, same reasoning
as above so the `PartitioningCollection` survives `ColumnPruning` under AQE.
##########
sql/core/src/main/scala/org/apache/spark/sql/execution/basicPhysicalOperators.scala:
##########
@@ -937,47 +940,76 @@ case class UnionExec(children: Seq[SparkPlan]) extends
SparkPlan with CodegenSup
}
override def outputPartitioning: Partitioning = {
- if (conf.getConf(SQLConf.UNION_OUTPUT_PARTITIONING)) {
- val partitionings = prepareOutputPartitioning()
- if (partitionings.forall(comparePartitioning(_, partitionings.head))) {
- val partitioner = partitionings.head
-
- // Take the output attributes of this union and map the partitioner to
them.
- val attributeMap = children.head.output.zip(output).toMap
- partitioner match {
- case headKp: KeyedPartitioning =>
- // A `UnionExec` concatenates its children's partitions in order
(one child's
- // partitions after another's), so the merged `KeyedPartitioning`
carries the
- // concatenation of the children's partition keys, one key per
physical output
- // partition. Children usually hold different key sets, so the
merged keys often
- // contain duplicates and `isGrouped` is false; a downstream
`GroupPartitionsExec`
- // regroups partitions that share a key. The children's
expressions have already
- // been remapped to the first child's attributes by
`prepareOutputPartitioning`;
- // here they are remapped to the union's output attributes.
- val mergedKeys = partitionings.flatMap {
- case k: KeyedPartitioning => k.partitionKeys
- case _ => return super.outputPartitioning
- }
- val mergedExpressions = headKp.expressions.map(_.transform {
- case a: Attribute if attributeMap.contains(a) => attributeMap(a)
- })
- val isGrouped = mergedKeys.distinct.size == mergedKeys.size
- val isNarrowed = partitionings.exists {
- case k: KeyedPartitioning => k.isNarrowed
- case _ => false
- }
- KeyedPartitioning(mergedExpressions, mergedKeys, isGrouped,
isNarrowed)
- case e: Expression =>
- e.transform {
- case a: Attribute if attributeMap.contains(a) => attributeMap(a)
- }.asInstanceOf[Partitioning]
- case _ => partitioner
- }
+ if (!conf.getConf(SQLConf.UNION_OUTPUT_PARTITIONING)) {
+ return super.outputPartitioning
+ }
+
+ // Children's partitionings with attributes remapped to the first child's
attributes.
+ val partitionings = prepareOutputPartitioning()
+ // Map from the first child's attributes to this union's own output
attributes.
+ val attributeMap = children.head.output.zip(output).toMap
+ def toUnionOutput(p: Partitioning): Partitioning = p match {
+ case e: Expression =>
+ e.transform {
+ case a: Attribute if attributeMap.contains(a) => attributeMap(a)
+ }.asInstanceOf[Partitioning]
+ case _ => p
+ }
+
+ // Case A: every child is a single `KeyedPartitioning`. A `UnionExec`
concatenates its
+ // children's partitions in order (one child's partitions after
another's), so the merged
+ // `KeyedPartitioning` carries the concatenation of the children's
partition keys, one key
+ // per physical output partition. Children usually hold different key
sets, so the merged
+ // keys often contain duplicates and `isGrouped` is false; a downstream
`GroupPartitionsExec`
+ // regroups partitions that share a key. This concatenation (numPartitions
= sum) is a
+ // distinct physical strategy from the co-located pass-through below
(numPartitions = N), so
+ // it is kept as a separate case and never folded into a
`PartitioningCollection`.
+ if (partitionings.forall(_.isInstanceOf[KeyedPartitioning])) {
+ val kps = partitionings.map(_.asInstanceOf[KeyedPartitioning])
+ val headKp = kps.head
+ // The `KeyedPartitioning`s must agree on the partition expressions to
merge.
+ val compatible = kps.forall(comparePartitioning(_, headKp))
+ if (compatible) {
+ val mergedKeys = kps.flatMap(_.partitionKeys)
+ val mergedExpressions = headKp.expressions.map(_.transform {
+ case a: Attribute if attributeMap.contains(a) => attributeMap(a)
+ })
+ val isGrouped = mergedKeys.distinct.size == mergedKeys.size
+ val isNarrowed = kps.exists(_.isNarrowed)
+ return KeyedPartitioning(mergedExpressions, mergedKeys, isGrouped,
isNarrowed)
} else {
- super.outputPartitioning
+ return super.outputPartitioning
}
- } else {
- super.outputPartitioning
+ }
+
+ // Case B: treat each child's partitioning as a set of candidate
partitionings (a
+ // `PartitioningCollection` flattens to its members; a single partitioning
is a one-element
+ // set) and pass through the intersection across all children. Only
index-co-locatable
+ // partitionings participate; `KeyedPartitioning` is excluded here because
its concatenation
+ // semantics (Case A) are incompatible with the co-located union RDD.
+ def flattenPartitioning(p: Partitioning): Seq[Partitioning] = p match {
Review Comment:
Done in b79f1b2. Rather than depend on the `sql/core` helper from catalyst,
I lifted a shared `PartitioningCollection.flatten` into the catalyst companion
object and reused it from both `UnionExec` and
`PartitioningPreservingUnaryExecNode`, removing the duplication.
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