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https://issues.apache.org/jira/browse/HIVE-5830?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13841877#comment-13841877
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Ashutosh Chauhan commented on HIVE-5830:
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Patch looks good. Can you add comments on what kind of query form we are
generating through all new static methods.
Also cross join of subq with count * will be expensive. As an optimization we
should convert such kind of joins where other side is an output of a function
always into a map-join. This will also give us an opportunity in this case to
pack subsequent LOJ into same MR task.
Though, this optimization is independent of this work and would be generally
useful outside of this use-case. Can you create a jira for that one?
> SubQuery: Not In subqueries should check if subquery contains nulls in
> matching column
> --------------------------------------------------------------------------------------
>
> Key: HIVE-5830
> URL: https://issues.apache.org/jira/browse/HIVE-5830
> Project: Hive
> Issue Type: Bug
> Components: Query Processor
> Reporter: Harish Butani
> Assignee: Harish Butani
> Fix For: 0.13.0
>
> Attachments: HIVE-5830.2.patch
>
>
> As pointed out by [~snarayanan] in HIVE-784 for not in when there are nulls
> in the SubQuery's matching column the Outer Query should return no rows.
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