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From "Tristan Stevens (JIRA)" <>
Subject [jira] [Commented] (HIVE-11266) count(*) wrong result based on table statistics
Date Wed, 08 Mar 2017 07:38:38 GMT


Tristan Stevens commented on HIVE-11266:

If Hive is still serving results directly from the stats then with external tables it cannot
guarantee their accuracy.

> count(*) wrong result based on table statistics
> -----------------------------------------------
>                 Key: HIVE-11266
>                 URL:
>             Project: Hive
>          Issue Type: Bug
>    Affects Versions: 1.1.0
>            Reporter: Simone Battaglia
>            Assignee: Pengcheng Xiong
>            Priority: Critical
> Hive returns wrong count result on an external table with table statistics if I change
table data files.
> This is the scenario in details:
> 1) create external table my_table (...) location 'my_location';
> 2) analyze table my_table compute statistics;
> 3) change/add/delete one or more files in 'my_location' directory;
> 4) select count(\*) from my_table;
> In this case the count query doesn't generate a MR job and returns the result based on
table statistics. This result is wrong because is based on statistics stored in the Hive metastore
and doesn't take into account modifications introduced on data files.
> Obviously setting "hive.compute.query.using.stats" to FALSE this problem doesn't occur
but the default value of this property is TRUE.
> I thinks that also this post on stackoverflow, that shows another type of bug in case
of multiple insert, is related to the one that I reported:

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