quickstep-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From jianqiao <...@git.apache.org>
Subject [GitHub] incubator-quickstep pull request #332: Small adjustments in star schema cost...
Date Wed, 07 Feb 2018 22:00:01 GMT
GitHub user jianqiao opened a pull request:

    https://github.com/apache/incubator-quickstep/pull/332

    Small adjustments in star schema cost model for # distinct values estimation

    This PR has a small adjustment in star schema cost model for # of distinct values estimation,
together with a fix to a potential bug with `impliesUniqueAttributes`.
    
    The adjustment is likely to improve query plans _when table stats are not present_. It
does not affect SSB/TPC-H performance.

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

    $ git pull https://github.com/jianqiao/incubator-quickstep adjust-cost

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

    https://github.com/apache/incubator-quickstep/pull/332.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 #332
    
----
commit 8e94a8e7ef6c99e5c64d1d96bb7283f9f1154116
Author: Jianqiao Zhu <jianqiao@...>
Date:   2018-02-07T21:42:15Z

    Small adjust in star schema cost model for # distinct values

----


---

Mime
View raw message