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https://issues.apache.org/jira/browse/SPARK-16475?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15370032#comment-15370032
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Dongjoon Hyun commented on SPARK-16475:
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Oh, Spark supports `Hint` really? Amazing. Sure. This is the interesting topic
of SQL optimization.
By the way, the scope of this issue maybe starts from SQLParser.
> Broadcast Hint for SQL Queries
> ------------------------------
>
> Key: SPARK-16475
> URL: https://issues.apache.org/jira/browse/SPARK-16475
> Project: Spark
> Issue Type: Improvement
> Reporter: Reynold Xin
> Attachments: BroadcastHintinSparkSQL.pdf
>
>
> Broadcast hint is a way for users to manually annotate a query and suggest to
> the query optimizer the join method. It is very useful when the query
> optimizer cannot make optimal decision with respect to join methods due to
> conservativeness or the lack of proper statistics.
> The DataFrame API has broadcast hint since Spark 1.5. However, we do not have
> an equivalent functionality in SQL queries. We propose adding Hive-style
> broadcast hint to Spark SQL.
> For more information, please see the attached document.
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