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From vraghavan78 <...@git.apache.org>
Subject [GitHub] incubator-hawq pull request: Fallback to planner for command: ALTE...
Date Fri, 15 Jan 2016 20:03:49 GMT
GitHub user vraghavan78 opened a pull request:

    https://github.com/apache/incubator-hawq/pull/273

    Fallback to planner for command: ALTER TABLE SET DISTRIBUTED BY

    When the user fires the following query: 
    ```
     alter table redist_test set with (reorganize=true) distributed  randomly;
    ```
    The intention of the user is to force redistribute the tuple so that there is no skew.

    
    Under the hood, GPDB first creates a temp table via CTAS and then replaces the table with
the temp table. Given that source table and the temp table are both random, Orca says random
satisfies random and therefore no tuple relocation via motions is needed. This changes the
expected behavior. 
    
    The fix inside Orca is quite extensive, so the immediate stop gap is to fall back to the
planner when we execute the CTAS.
    #permalink


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

    $ git pull https://github.com/vraghavan78/incubator-hawq altertbl

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

    https://github.com/apache/incubator-hawq/pull/273.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 #273
    
----
commit 90ab2d40663c06cf87b40ab38c5ffb36c044fdc3
Author: Venkatesh Raghavan <vraghavan@pivotal.io>
Date:   2016-01-15T20:01:46Z

    Fallback to planner for command: ALTER TABLE SET DISTRIBUTED BY

----


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