[jira] [Comment Edited] (HIVE-15539) Optimize complex multi-insert queries in Calcite

["Jesus Camacho Rodriguez (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HIVE-15539?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15805361#comment-15805361 ] 

Jesus Camacho Rodriguez edited comment on HIVE-15539 at 1/6/17 7:22 PM:
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[~vgarg], I have regenerated the q files and changes seem fine. Could you review it?

https://reviews.apache.org/r/55276/

Thanks


was (Author: jcamachorodriguez):
[~vgarg], I have regenerated the q files and changes seem fine. Could you review it? Thanks

> Optimize complex multi-insert queries in Calcite
> ------------------------------------------------
>
>                 Key: HIVE-15539
>                 URL: https://issues.apache.org/jira/browse/HIVE-15539
>             Project: Hive
>          Issue Type: Improvement
>          Components: Parser
>    Affects Versions: 2.2.0
>            Reporter: Jesus Camacho Rodriguez
>            Assignee: Jesus Camacho Rodriguez
>         Attachments: HIVE-15539.03.patch, HIVE-15539.04.patch
>
>
> Currently multi-insert queries are not optimized by Calcite. Proper integration with Calcite would include creating a _spool_ operator whose output is reused by every _insert_ statement; however, _spool_ operator has not been added to Calcite yet (CALCITE-481).
> In the meantime, and since complex logic for multi-insert queries is in FROM clause, we can optimize the FROM clause with Calcite and connect the optimized result to the original query.
> Initially, we will recognize three different cases:
> - FROM clause is trivial, e.g., table reference, or not supported. No need to optimize with Calcite.
> - FROM clause is a subquery. Optimize the subquery with Calcite.
> - FROM clause is a join. Rewrite join into a subquery and optimize it with Calcite. Change references in INSERT statements to refer to subquery columns.
> This should be beneficial for MERGE statements processing too, since MERGE statements are treated as multi-insert queries by Hive.



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