[
https://issues.apache.org/jira/browse/TAJO-2007?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15057686#comment-15057686
]
ASF GitHub Bot commented on TAJO-2007:
--------------------------------------
Github user jihoonson commented on the pull request:
https://github.com/apache/tajo/pull/900#issuecomment-164696159
@hyunsik thanks for your work. Even though this patch contains lots of
changes, the code change is very minor. These changes look good.
In addition, changes in tests also look good. Honestly, I think we can do
more realistic query plan tests on TPC-H tables.
The only thing I'm concerned with is that some tests are intended to test
broadcast join, but are not actually executed with broadcast join. I think we
need to change the test query. Do you have any good idea?
> By default, Optimizer should use the table volume in TableStat.
> ---------------------------------------------------------------
>
> Key: TAJO-2007
> URL: https://issues.apache.org/jira/browse/TAJO-2007
> Project: Tajo
> Issue Type: Improvement
> Components: Planner/Optimizer
> Reporter: Hyunsik Choi
> Assignee: Hyunsik Choi
> Fix For: 0.12.0, 0.11.1
>
>
> Currently, the optimizer by default gets table volumes through storage
> manager and employ them for join optimization. But, in some cases, it causes
> performance degradation because aggregating all file volumes is not cheap in
> large partitioned tables on S3 or HDFS.
> So, this patch improves TableStatUpdateRewriter to use table volumes of
> TableStat by default, and it also adds a session variable 'USE_TABLE_VOLUME'
> to allow the optimizer to use the table volume through storage handler.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
