[jira] [Assigned] (HIVE-19684) Hive stats optimizer wrongly uses stats against non native tables

["slim bouguerra (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HIVE-19684?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

slim bouguerra reassigned HIVE-19684:
-------------------------------------


> Hive stats optimizer wrongly uses stats against non native tables
> -----------------------------------------------------------------
>
>                 Key: HIVE-19684
>                 URL: https://issues.apache.org/jira/browse/HIVE-19684
>             Project: Hive
>          Issue Type: Bug
>            Reporter: slim bouguerra
>            Assignee: slim bouguerra
>            Priority: Major
>
> Stats of non native tables are inaccurate, thus queries over non native tables can not optimized by stats optimizer.
> Take example of query 
> {code}
> Explain select count(*) from (select `__time` from druid_test_table limit 1) as src ;
> {code} 
> the plan will be reduced to 
> {code}
> POSTHOOK: query: explain extended select count(*) from (select `__time` from druid_test_table limit 1) as src
> POSTHOOK: type: QUERY
> STAGE DEPENDENCIES:
>   Stage-0 is a root stage
> STAGE PLANS:
>   Stage: Stage-0
>     Fetch Operator
>       limit: 1
>       Processor Tree:
>         ListSink
> {code}



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