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https://issues.apache.org/jira/browse/HIVE-12963?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Alina Abramova updated HIVE-12963:
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    Attachment: HIVE-12244.2.patch

> LIMIT statement with SORT BY creates additional MR job with hardcoded only 
> one reducer
> --------------------------------------------------------------------------------------
>
>                 Key: HIVE-12963
>                 URL: https://issues.apache.org/jira/browse/HIVE-12963
>             Project: Hive
>          Issue Type: Bug
>          Components: Hive
>    Affects Versions: 1.0.0, 1.2.1, 0.13
>            Reporter: Alina Abramova
>            Assignee: Alina Abramova
>         Attachments: HIVE-12963.1.patch
>
>
> I execute query:
> hive> select age from test1 sort by age.age  limit 10;                      
> Total jobs = 2
> Launching Job 1 out of 2
> Number of reduce tasks not specified. Estimated from input data size: 1
> Launching Job 2 out of 2
> Number of reduce tasks determined at compile time: 1
> When I have a large number of rows then the last stage of the job takes a 
> long time. I think we could allow to user choose number of reducers of last 
> job or refuse extra MR job.
> The same behavior I observed with queries:
> hive> create table new_test as select age from test1 group by age.age  limit 
> 10;



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