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https://issues.apache.org/jira/browse/HIVE-15721?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15839566#comment-15839566
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Lefty Leverenz commented on HIVE-15721:
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Doc note: This removes the restriction that HIVE-15544 said would need to be
documented (also in release 2.2.0), so actually this is an "undocumentation
note" -- see these comments on HIVE-15544:
* [restriction comment on HIVE-15544 |
https://issues.apache.org/jira/browse/HIVE-15544?focusedCommentId=15829209&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-15829209]
* [doc comment on HIVE-15544 |
https://issues.apache.org/jira/browse/HIVE-15544?focusedCommentId=15833334&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-15833334]
> Allow IN/NOT IN correlated subquery with aggregates
> ----------------------------------------------------
>
> Key: HIVE-15721
> URL: https://issues.apache.org/jira/browse/HIVE-15721
> Project: Hive
> Issue Type: Sub-task
> Components: Query Planning
> Reporter: Vineet Garg
> Assignee: Vineet Garg
> Labels: TODOC2.2, sub-query
> Fix For: 2.2.0
>
> Attachments: HIVE-15721.1.patch, HIVE-15721.2.patch
>
>
> With HIVE-15544 IN/NOT IN correlated subqueries with aggregates were disabled
> since re-writting them into JOIN could have produced wrong result.
> Wrong results would occur if subquery produces zero row, since aggregate
> always produce result lower such query into LEFT JOIN or SEMI JOIN would not
> take these case into consideration.
> We propose to allow such queries with an added run time check which will
> throw an error/exception if subquery produces zero row.
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