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https://issues.apache.org/jira/browse/SPARK-13919?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15202116#comment-15202116
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Apache Spark commented on SPARK-13919:
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User 'davies' has created a pull request for this issue:
https://github.com/apache/spark/pull/11828
> Resolving the Conflicts of ColumnPruning and PushPredicateThroughProject
> -------------------------------------------------------------------------
>
> Key: SPARK-13919
> URL: https://issues.apache.org/jira/browse/SPARK-13919
> Project: Spark
> Issue Type: Improvement
> Components: SQL
> Affects Versions: 2.0.0
> Reporter: Xiao Li
>
> Now, {{ColumnPruning}} and {{PushPredicateThroughProject}} reverse each
> other's effect. Although it will not cause the max iteration now, some
> queries are not optimized to the best.
> For example, in the following query,
> {code}
> val input = LocalRelation('a.int, 'b.string, 'c.double, 'd.int)
> val originalQuery =
> input.select('a, 'b, 'c, 'd,
> WindowExpression(
> AggregateExpression(Count('b), Complete, isDistinct = false),
> WindowSpecDefinition( 'a :: Nil,
> SortOrder('b, Ascending) :: Nil,
> UnspecifiedFrame)).as('window)).where('window > 1).select('a, 'c)
> {code}
> After multiple iteration of two rules of {{ColumnPruning}} and
> {{PushPredicateThroughProject}}, the optimized plan we generated is like:
> {code}
> Project [a#0,c#0]
>
>
> +- Filter (window#0L > cast(1 as bigint))
>
>
> +- Project [a#0,c#0,window#0L]
>
>
> +- Window [(count(b#0),mode=Complete,isDistinct=false)
> windowspecdefinition(a#0, b#0 ASC, RANGE BETWEEN UNBOUNDED PRECEDING AND
> CURRENT ROW) AS window#0L], [a#0], [b#0 ASC]
> +- LocalRelation [a#0,b#0,c#0,d#0]
>
>
> {code}
> However, the expected optimized plan should be like:
> {code}
> Project [a#0,c#0]
> +- Filter (window#0L > cast(1 as bigint))
> +- Project [a#0,c#0,window#0L]
> +- Window [(count(b#0),mode=Complete,isDistinct=false)
> windowspecdefinition(a#0, b#0 ASC, RANGE BETWEEN UNBOUNDED PRECEDING AND
> CURRENT ROW) AS window#0L], [a#0], [b#0 ASC]
> +- Project [a#0,b#0,c#0]
> +- LocalRelation [a#0,b#0,c#0,d#0]
>
>
> {code}
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