[
https://issues.apache.org/jira/browse/HIVE-12963?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Alina Abramova updated HIVE-12963:
----------------------------------
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;
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
