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https://issues.apache.org/jira/browse/SPARK-1461?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13973830#comment-13973830
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Cheng Hao commented on SPARK-1461:
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The PR https://github.com/apache/spark/pull/446
> Support Short-circuit Expression Evaluation
> -------------------------------------------
>
> Key: SPARK-1461
> URL: https://issues.apache.org/jira/browse/SPARK-1461
> Project: Spark
> Issue Type: Improvement
> Components: SQL
> Reporter: Cheng Hao
> Assignee: Cheng Hao
> Fix For: 1.1.0
>
>
> Short-circuit expression evaluation impacts the performance significantly.
> e.g.
> In expression: (a>b) && (c>d), if a>b equals false or null, the expression
> value is false or null definitely without considering the value of sub
> expression c>d.
> However, if c or d contains a stateful UDF (for example, the UDF
> row_sequence) as its child expression, we have to evaluate the stateful
> expression but ignore its result.
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