Github user chenghao-intel commented on a diff in the pull request:
https://github.com/apache/spark/pull/1935#discussion_r16221796
--- Diff:
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/aggregates.scala
---
@@ -65,6 +65,80 @@ abstract class PartialAggregate extends
AggregateExpression {
def asPartial: SplitEvaluation
}
+abstract class MergeableAggregate extends PartialAggregate {
+ self: Product =>
+
+ def asPartial: SplitEvaluation = {
+ val partialValues = Alias(ReturnAggregate(this), "partialValue")()
+ SplitEvaluation(
+ MergeAggregates(partialValues.toAttribute),
+ partialValues :: Nil
+ )
+ }
+
+ def newInstance(): MergableAggregateFunction
+}
+
+case class ReturnAggregate(child: AggregateExpression)
+ extends AggregateExpression with Serializable with
trees.UnaryNode[Expression] {
+
+ def dataType = child.dataType
+
+ def nullable = child.nullable
+
+ def references = child.references
+
+ def newInstance() = new ReturnAggregateFunction(child, this)
--- End diff --
Oh, sorry, understood. the result of `eval` is the AggregateFunction itself.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
