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From "Ashutosh Chauhan (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HIVE-4197) Bring windowing support inline with SQL Standard
Date Fri, 22 Mar 2013 13:07:29 GMT

    [ https://issues.apache.org/jira/browse/HIVE-4197?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13610242#comment-13610242
] 

Ashutosh Chauhan commented on HIVE-4197:
----------------------------------------

Hmm.. One way I can think of is to sort rows ourselves. We need to add an extra column in
mapper (combination of task.id and monotonic increasing row number) and than in PTFOperator
have an implementation of ByteBasedList which uses Priority Queue to store data in memory
instead of ByteBuffer. This Priority Queue will insert data in order of this new column we
added and dropping it soon after.
However, this seems to me is pretty heavy-handed approach. I will prefer something simpler.
Harish, this problem of stable sort is getting exposed only on hadoop2, so I will suggest
for now lets focus on other issues as we think and come up with a better solution for it,
since on hadoop1 we don't have such a problem.

                
> Bring windowing support inline with SQL Standard
> ------------------------------------------------
>
>                 Key: HIVE-4197
>                 URL: https://issues.apache.org/jira/browse/HIVE-4197
>             Project: Hive
>          Issue Type: Bug
>          Components: PTF-Windowing
>            Reporter: Harish Butani
>         Attachments: WindowingSpecification.pdf
>
>
> The current behavior defers from the Standard in several significant places.
> Please review attached doc; there are still a few open issues. Once we agree on the behavior,
can proceed with fixing the implementation.

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