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https://issues.apache.org/jira/browse/TAJO-2007?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15055238#comment-15055238
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ASF GitHub Bot commented on TAJO-2007:
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Github user blrunner commented on the pull request:
https://github.com/apache/tajo/pull/900#issuecomment-164317909
Thank you for your contribution.
I'm reviewing this PR. :)
> 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.
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