[jira] [Commented] (DRILL-4147) Union All operator runs in a single fragment

["ASF GitHub Bot (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/DRILL-4147?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15399895#comment-15399895 ] 

ASF GitHub Bot commented on DRILL-4147:
---------------------------------------

GitHub user amansinha100 opened a pull request:

    https://github.com/apache/drill/pull/555

    DRILL-4147: Change union-all distribution trait to inherit that of it…

    …s child (ANY).
    
    Additional unit tests.

You can merge this pull request into a Git repository by running:

    $ git pull https://github.com/amansinha100/incubator-drill DRILL-4147

Alternatively you can review and apply these changes as the patch at:

    https://github.com/apache/drill/pull/555.patch

To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:

    This closes #555
    
----
commit 2a58c54999ac665ddd26ea8ebc82098c587bbc4f
Author: Aman Sinha <as...@maprtech.com>
Date:   2015-12-02T00:46:51Z

    DRILL-4147: Change union-all distribution trait to inherit that of its child (ANY).
    
    Additional unit tests.

----


> Union All operator runs in a single fragment
> --------------------------------------------
>
>                 Key: DRILL-4147
>                 URL: https://issues.apache.org/jira/browse/DRILL-4147
>             Project: Apache Drill
>          Issue Type: Bug
>            Reporter: amit hadke
>            Assignee: Aman Sinha
>
> A User noticed that running select  from a single directory is much faster than union all on two directories.
> (https://drill.apache.org/blog/2014/12/09/running-sql-queries-on-amazon-s3/#comment-2349732267) 
> It seems like UNION ALL operator doesn't parallelize sub scans (its using SINGLETON for distribution type). Everything is ran in single fragment.
> We may have to use SubsetTransformer in UnionAllPrule.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)