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Posted to issues@hive.apache.org by "Stamatis Zampetakis (Jira)" <ji...@apache.org> on 2024/07/01 07:56:00 UTC

[jira] [Resolved] (HIVE-28310) Disable hive.optimize.join.disjunctive.transitive.predicates.pushdown by default

     [ https://issues.apache.org/jira/browse/HIVE-28310?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Stamatis Zampetakis resolved HIVE-28310.
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    Fix Version/s: 4.1.0
       Resolution: Fixed

Fixed in https://github.com/apache/hive/commit/a875a455867979758e24e51f97481f62ad80bc07

Thanks for the reviews [~asolimando] and [~kkasa]!

> Disable hive.optimize.join.disjunctive.transitive.predicates.pushdown by default
> --------------------------------------------------------------------------------
>
>                 Key: HIVE-28310
>                 URL: https://issues.apache.org/jira/browse/HIVE-28310
>             Project: Hive
>          Issue Type: Task
>          Components: CBO
>    Affects Versions: 4.0.0
>            Reporter: Stamatis Zampetakis
>            Assignee: Stamatis Zampetakis
>            Priority: Major
>              Labels: pull-request-available
>             Fix For: 4.1.0
>
>
> HIVE-25758 introduced hive.optimize.join.disjunctive.transitive.predicates.pushdown  to conditionally limit some features of the HiveJoinPushTransitivePredicatesRule which are rather unsafe and can lead to Hiveserver2 crashes (OOM, hangs, etc.). 
> The property was initially set to true to retain the old behavior and prevent changes in performance for those queries that work fine as is. However, when the property is true there are various known cases/queries that can bring down HS2 completely. When this happens debugging, finding the root cause, and turning off the property may require lots of effort from developers and users.
> In this ticket, we propose to disable the property by default and thus limit the optimizations performed by the rule (at least till a complete solution is found for the known problematic cases).
> This change favors HS2 stability at the expense of slight performance degradation in certain queries.



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