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From DaveBirdsall <...@git.apache.org>
Subject [GitHub] incubator-trafodion pull request #1043: [TRAFODION-25] Temporary code for UP...
Date Mon, 03 Apr 2017 20:20:28 GMT
GitHub user DaveBirdsall opened a pull request:

    https://github.com/apache/incubator-trafodion/pull/1043

    [TRAFODION-25] Temporary code for UPDATE costing

    This adds some temporary code for UPDATE costing.
    
    The existing code returns a constant value for cost on all UPDATE operations; it is a
stub that was put in when the predecessor product was ported to Hadoop and HBase. The temporary
code is a copy of the costing code for DELETE. It is being put in because we have an immediate
need for parallel UPDATE plans in a particular application, which you don't get with the current
stub.
    
    This temporary code, of course, uses the DELETE theory of operation, which understates
the costs for UPDATE in general. So it is a stop-gap until better code can be written.
    
    To turn on this code, one must issue CQD HBASE_UPDATE_COSTING 'ON'. Without this CQD,
the old stub, a constant cost of 1, will be used.

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

    $ git pull https://github.com/DaveBirdsall/incubator-trafodion Trafodion25u

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

    https://github.com/apache/incubator-trafodion/pull/1043.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 #1043
    
----
commit 55e65d2b2a65153c6d5ef58d994980795560f72f
Author: Dave Birdsall <dbirdsall@apache.org>
Date:   2017-04-03T20:15:46Z

    [TRAFODION-25] Temporary code for UPDATE costing

----


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