WangGuangxin commented on a change in pull request #26011: [SPARK-29343][SQL]
Eliminate sorts without limit in the subquery of Join/Aggregation
URL: https://github.com/apache/spark/pull/26011#discussion_r344989239
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File path:
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/Optimizer.scala
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@@ -953,40 +952,62 @@ object CombineFilters extends Rule[LogicalPlan] with
PredicateHelper {
}
/**
- * Removes no-op SortOrder from Sort
+ * Removes Sort operation. This can happen:
+ * 1) if the sort order is empty or the sort order does not have any reference
+ * 2) if the child is already sorted
+ * 3) if there is another Sort operator separated by 0...n Project/Filter
operators
+ * 4) if the Sort operator is within Join separated by 0...n Project/Filter
operators only,
+ * and the Join conditions is deterministic
+ * 5) if the Sort operator is within GroupBy separated by 0...n Project/Filter
operators only,
+ * and the aggregate function is order irrelevant
*/
object EliminateSorts extends Rule[LogicalPlan] {
def apply(plan: LogicalPlan): LogicalPlan = plan transform {
case s @ Sort(orders, _, child) if orders.isEmpty ||
orders.exists(_.child.foldable) =>
val newOrders = orders.filterNot(_.child.foldable)
if (newOrders.isEmpty) child else s.copy(order = newOrders)
- }
-}
-
-/**
- * Removes redundant Sort operation. This can happen:
- * 1) if the child is already sorted
- * 2) if there is another Sort operator separated by 0...n Project/Filter
operators
- */
-object RemoveRedundantSorts extends Rule[LogicalPlan] {
- def apply(plan: LogicalPlan): LogicalPlan = plan transformDown {
case Sort(orders, true, child) if
SortOrder.orderingSatisfies(child.outputOrdering, orders) =>
child
case s @ Sort(_, _, child) => s.copy(child = recursiveRemoveSort(child))
+ case j @ Join(originLeft, originRight, _, cond, _) if
cond.forall(_.deterministic) =>
+ j.copy(left = recursiveRemoveSort(originLeft), right =
recursiveRemoveSort(originRight))
+ case g @ Aggregate(_, aggs, originChild) if isOrderIrrelevantAggs(aggs) =>
+ g.copy(child = recursiveRemoveSort(originChild))
}
- def recursiveRemoveSort(plan: LogicalPlan): LogicalPlan = plan match {
+ private def recursiveRemoveSort(plan: LogicalPlan): LogicalPlan = plan match
{
case Sort(_, _, child) => recursiveRemoveSort(child)
case other if canEliminateSort(other) =>
other.withNewChildren(other.children.map(recursiveRemoveSort))
case _ => plan
}
- def canEliminateSort(plan: LogicalPlan): Boolean = plan match {
+ private def canEliminateSort(plan: LogicalPlan): Boolean = plan match {
case p: Project => p.projectList.forall(_.deterministic)
case f: Filter => f.condition.deterministic
case _ => false
}
+
+ private def isOrderIrrelevantAggs(aggs: Seq[NamedExpression]): Boolean = {
+ def isOrderIrrelevantAggFunction(func: AggregateFunction): Boolean = func
match {
+ case _: Sum => true
+ case _: Min => true
+ case _: Max => true
+ case _: Count => true
+ case _: Average => true
Review comment:
Sure, I'll fix it in a followup
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