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https://issues.apache.org/jira/browse/HIVE-15771?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Prasanth Jayachandran updated HIVE-15771:
-----------------------------------------
Description:
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 expected join order.
was:
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.
> 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 expected join order.
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