[jira] [Assigned] (HIVE-24929) Allow correlated exists subqueries with windowing clause

["Krisztian Kasa (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HIVE-24929?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Krisztian Kasa reassigned HIVE-24929:
-------------------------------------


> Allow correlated exists subqueries with windowing clause
> --------------------------------------------------------
>
>                 Key: HIVE-24929
>                 URL: https://issues.apache.org/jira/browse/HIVE-24929
>             Project: Hive
>          Issue Type: Improvement
>          Components: Query Planning
>            Reporter: Krisztian Kasa
>            Assignee: Krisztian Kasa
>            Priority: Major
>             Fix For: 4.0.0
>
>
> Currently queries which has windowing clause with subqueries are not supported by Hive: Hive rewrites subqueries to joins and the rewritten plan would lead to incorrect results such cases.
> However this restriction can be lifted in case of Exists/Not exists subqueries since those cases we don not interested in the result of the window function call but the existence of any record.
> {code}
> select id, int_col
> from alltypesagg a
> where exists
>   (select sum(int_col) over (partition by bool_col)
>    from alltypestiny b
>    where a.id = b.id);
> {code}
> {code}
> select id, int_col from alltypestiny t
> where not exists
>   (select sum(int_col) over (partition by bool_col)
>    from alltypesagg a where t.id = a.int_col);
> {code}



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