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From "Ashutosh Chauhan (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HIVE-11573) PointLookupOptimizer can be pessimistic at a low nDV
Date Mon, 24 Aug 2015 16:12:45 GMT

    [ https://issues.apache.org/jira/browse/HIVE-11573?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14709525#comment-14709525
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Ashutosh Chauhan commented on HIVE-11573:
-----------------------------------------

I agree there is no good reason for storing original predicate in FilterDesc any more.

> PointLookupOptimizer can be pessimistic at a low nDV
> ----------------------------------------------------
>
>                 Key: HIVE-11573
>                 URL: https://issues.apache.org/jira/browse/HIVE-11573
>             Project: Hive
>          Issue Type: Bug
>    Affects Versions: 1.3.0, 2.0.0
>            Reporter: Gopal V
>            Assignee: Gopal V
>              Labels: TODOC2.0
>             Fix For: 1.3.0, 2.0.0
>
>         Attachments: HIVE-11573.1.patch, HIVE-11573.2.patch, HIVE-11573.3.patch, HIVE-11573.4.patch,
HIVE-11573.5.patch
>
>
> The PointLookupOptimizer can turn off some of the optimizations due to its use of tuple
IN() clauses.
> Limit the application of the optimizer for very low nDV cases and extract the sub-clause
as a pre-condition during runtime, to trigger the simple column predicate index lookups.



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