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https://issues.apache.org/jira/browse/HIVE-15771?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15847698#comment-15847698
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Prasanth Jayachandran commented on HIVE-15771:
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cc/ [~ashutoshc] [~jcamachorodriguez] [~pxiong]
> CBO chooses wrong join order for TPC-DS query72
> -----------------------------------------------
>
> Key: HIVE-15771
> URL: https://issues.apache.org/jira/browse/HIVE-15771
> Project: Hive
> Issue Type: Bug
> Components: CBO
> Affects Versions: 2.2.0
> Reporter: Prasanth Jayachandran
> Priority: Critical
> Attachments: q72-explain.txt, q72-mod-explain.txt, q72-mod.svg,
> q72.svg, query72-mod.sql, query72.sql
>
>
> Query72 of TPC-DS on 1TB scale generates wrong join order resulting in
> increased query execution time. It chooses fact-to-fact table join followed
> by joins with dimension tables as opposed to doing map-join with dimension
> tables first and doing the fact-to-fact table join at the last.
> Please find attachment for the join order selected by CBO vs rewritten query
> with correct join order.
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