anchovYu commented on code in PR #42276:
URL: https://github.com/apache/spark/pull/42276#discussion_r1286515285
##########
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/ResolveLateralColumnAliasReference.scala:
##########
@@ -131,95 +131,97 @@ object ResolveLateralColumnAliasReference extends
Rule[LogicalPlan] {
(pList.exists(hasWindowExpression) && p.expressions.forall(_.resolved)
&& p.childrenResolved)
}
- override def apply(plan: LogicalPlan): LogicalPlan = {
- if (!conf.getConf(SQLConf.LATERAL_COLUMN_ALIAS_IMPLICIT_ENABLED)) {
- plan
- } else if (plan.containsAnyPattern(TEMP_RESOLVED_COLUMN,
UNRESOLVED_HAVING)) {
- // It should not change the plan if `TempResolvedColumn` or
`UnresolvedHaving` is present in
- // the query plan. These plans need certain plan shape to get recognized
and resolved by other
- // rules, such as Filter/Sort + Aggregate to be matched by
ResolveAggregateFunctions.
- // LCA resolution can break the plan shape, like adding Project above
Aggregate.
- plan
- } else {
- // phase 2: unwrap
- plan.resolveOperatorsUpWithPruning(
- _.containsPattern(LATERAL_COLUMN_ALIAS_REFERENCE), ruleId) {
- case p @ Project(projectList, child) if ruleApplicableOnOperator(p,
projectList)
- &&
projectList.exists(_.containsPattern(LATERAL_COLUMN_ALIAS_REFERENCE)) =>
- var aliasMap = AttributeMap.empty[AliasEntry]
- val referencedAliases = collection.mutable.Set.empty[AliasEntry]
- def unwrapLCAReference(e: NamedExpression): NamedExpression = {
-
e.transformWithPruning(_.containsPattern(LATERAL_COLUMN_ALIAS_REFERENCE)) {
- case lcaRef: LateralColumnAliasReference if
aliasMap.contains(lcaRef.a) =>
- val aliasEntry = aliasMap.get(lcaRef.a).get
- // If there is no chaining of lateral column alias reference,
push down the alias
- // and unwrap the LateralColumnAliasReference to the
NamedExpression inside
- // If there is chaining, don't resolve and save to future
rounds
- if
(!aliasEntry.alias.containsPattern(LATERAL_COLUMN_ALIAS_REFERENCE)) {
- referencedAliases += aliasEntry
- lcaRef.ne
- } else {
- lcaRef
- }
- case lcaRef: LateralColumnAliasReference if
!aliasMap.contains(lcaRef.a) =>
- // It shouldn't happen, but restore to unresolved attribute to
be safe.
- UnresolvedAttribute(lcaRef.nameParts)
- }.asInstanceOf[NamedExpression]
- }
- val newProjectList = projectList.zipWithIndex.map {
- case (a: Alias, idx) =>
- val lcaResolved = unwrapLCAReference(a)
- // Insert the original alias instead of rewritten one to detect
chained LCA
- aliasMap += (a.toAttribute -> AliasEntry(a, idx))
- lcaResolved
- case (e, _) =>
- unwrapLCAReference(e)
- }
+ /** Internal application method. A hand-written bottom-up recursive
traverse. */
+ private def apply0(plan: LogicalPlan): LogicalPlan = {
+ plan match {
+ case p: LogicalPlan if
!p.containsPattern(LATERAL_COLUMN_ALIAS_REFERENCE) =>
+ p
- if (referencedAliases.isEmpty) {
- p
- } else {
- val outerProjectList = collection.mutable.Seq(newProjectList: _*)
- val innerProjectList =
-
collection.mutable.ArrayBuffer(child.output.map(_.asInstanceOf[NamedExpression]):
_*)
- referencedAliases.foreach { case AliasEntry(alias: Alias, idx) =>
- outerProjectList.update(idx, alias.toAttribute)
- innerProjectList += alias
- }
- p.copy(
- projectList = outerProjectList.toSeq,
- child = Project(innerProjectList.toSeq, child)
- )
- }
+ // It should not change the Aggregate (and thus the plan shape) if its
parent is an
+ // UnresolvedHaving, to avoid breaking the shape pattern
`UnresolvedHaving - Aggregate`
+ // matched by ResolveAggregateFunctions. See SPARK-42936 and SPARK-44714
for more details.
+ case u @ UnresolvedHaving(_, agg: Aggregate) =>
+ u.copy(child = agg.mapChildren(apply0))
- case agg @ Aggregate(groupingExpressions, aggregateExpressions, _)
- if ruleApplicableOnOperator(agg, aggregateExpressions)
- &&
aggregateExpressions.exists(_.containsPattern(LATERAL_COLUMN_ALIAS_REFERENCE))
=>
+ case pOriginal: Project if ruleApplicableOnOperator(pOriginal,
pOriginal.projectList)
+ &&
pOriginal.projectList.exists(_.containsPattern(LATERAL_COLUMN_ALIAS_REFERENCE))
=>
+ val p @ Project(projectList, child) = pOriginal.mapChildren(apply0)
+ var aliasMap = AttributeMap.empty[AliasEntry]
+ val referencedAliases = collection.mutable.Set.empty[AliasEntry]
+ def unwrapLCAReference(e: NamedExpression): NamedExpression = {
+
e.transformWithPruning(_.containsPattern(LATERAL_COLUMN_ALIAS_REFERENCE)) {
+ case lcaRef: LateralColumnAliasReference if
aliasMap.contains(lcaRef.a) =>
+ val aliasEntry = aliasMap.get(lcaRef.a).get
+ // If there is no chaining of lateral column alias reference,
push down the alias
+ // and unwrap the LateralColumnAliasReference to the
NamedExpression inside
+ // If there is chaining, don't resolve and save to future rounds
+ if
(!aliasEntry.alias.containsPattern(LATERAL_COLUMN_ALIAS_REFERENCE)) {
+ referencedAliases += aliasEntry
+ lcaRef.ne
+ } else {
+ lcaRef
+ }
+ case lcaRef: LateralColumnAliasReference if
!aliasMap.contains(lcaRef.a) =>
+ // It shouldn't happen, but restore to unresolved attribute to
be safe.
+ UnresolvedAttribute(lcaRef.nameParts)
+ }.asInstanceOf[NamedExpression]
+ }
+ val newProjectList = projectList.zipWithIndex.map {
+ case (a: Alias, idx) =>
+ val lcaResolved = unwrapLCAReference(a)
+ // Insert the original alias instead of rewritten one to detect
chained LCA
+ aliasMap += (a.toAttribute -> AliasEntry(a, idx))
+ lcaResolved
+ case (e, _) =>
+ unwrapLCAReference(e)
+ }
- // Check if current Aggregate is eligible to lift up with Project:
the aggregate
- // expression only contains: 1) aggregate functions, 2) grouping
expressions, 3) leaf
- // expressions excluding attributes not in grouping expressions
- // This check is to prevent unnecessary transformation on invalid
plan, to guarantee it
- // throws the same exception. For example, cases like non-aggregate
expressions not
- // in group by, once transformed, will throw a different exception:
missing input.
- def eligibleToLiftUp(exp: Expression): Boolean = {
- exp match {
- case _: AggregateExpression => true
- case e if groupingExpressions.exists(_.semanticEquals(e)) => true
- case a: Attribute => false
- case s: ScalarSubquery if s.children.nonEmpty
- && !groupingExpressions.exists(_.semanticEquals(s)) => false
- // Manually skip detection on function itself because it can be
an aggregate function.
- // This is to avoid expressions like sum(salary) over ()
eligible to lift up.
- case WindowExpression(function, spec) =>
- function.children.forall(eligibleToLiftUp) &&
eligibleToLiftUp(spec)
- case e => e.children.forall(eligibleToLiftUp)
- }
- }
- if (!aggregateExpressions.forall(eligibleToLiftUp)) {
- return agg
+ if (referencedAliases.isEmpty) {
+ p
+ } else {
+ val outerProjectList = collection.mutable.Seq(newProjectList: _*)
+ val innerProjectList =
+
collection.mutable.ArrayBuffer(child.output.map(_.asInstanceOf[NamedExpression]):
_*)
+ referencedAliases.foreach { case AliasEntry(alias: Alias, idx) =>
+ outerProjectList.update(idx, alias.toAttribute)
+ innerProjectList += alias
}
+ p.copy(
+ projectList = outerProjectList.toSeq,
+ child = Project(innerProjectList.toSeq, child)
+ )
+ }
+
+ case aggOriginal: Aggregate
+ if ruleApplicableOnOperator(aggOriginal,
aggOriginal.aggregateExpressions)
+ && aggOriginal.aggregateExpressions.exists(
+ _.containsPattern(LATERAL_COLUMN_ALIAS_REFERENCE)) =>
+ val agg @ Aggregate(groupingExpressions, aggregateExpressions, _) =
+ aggOriginal.mapChildren(apply0)
+ // Check if current Aggregate is eligible to lift up with Project: the
aggregate
+ // expression only contains: 1) aggregate functions, 2) grouping
expressions, 3) leaf
+ // expressions excluding attributes not in grouping expressions
+ // This check is to prevent unnecessary transformation on invalid
plan, to guarantee it
+ // throws the same exception. For example, cases like non-aggregate
expressions not
+ // in group by, once transformed, will throw a different exception:
missing input.
+ def eligibleToLiftUp(exp: Expression): Boolean = {
+ exp match {
+ case _: AggregateExpression => true
+ case e if groupingExpressions.exists(_.semanticEquals(e)) => true
+ case a: Attribute => false
+ case s: ScalarSubquery if s.children.nonEmpty
+ && !groupingExpressions.exists(_.semanticEquals(s)) => false
+ // Manually skip detection on function itself because it can be an
aggregate function.
+ // This is to avoid expressions like sum(salary) over () eligible
to lift up.
+ case WindowExpression(function, spec) =>
+ function.children.forall(eligibleToLiftUp) &&
eligibleToLiftUp(spec)
+ case e => e.children.forall(eligibleToLiftUp)
+ }
+ }
+ if (!aggregateExpressions.forall(eligibleToLiftUp)) {
+ agg
Review Comment:
Previously this line was `return agg`. That could be risky to `return` in a
closure.. But for `apply0` with or without return should be the same.
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