hive-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Pradeep Kamath (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HIVE-3733) Improve Hive's logic for conditional merge
Date Fri, 07 Dec 2012 06:05:22 GMT

    [ https://issues.apache.org/jira/browse/HIVE-3733?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13526161#comment-13526161
] 

Pradeep Kamath commented on HIVE-3733:
--------------------------------------

Hi Namit - HIVE-3733.4.patch.txt has the most recent full patch.
                
> Improve Hive's logic for conditional merge
> ------------------------------------------
>
>                 Key: HIVE-3733
>                 URL: https://issues.apache.org/jira/browse/HIVE-3733
>             Project: Hive
>          Issue Type: Improvement
>            Reporter: Pradeep Kamath
>            Assignee: Pradeep Kamath
>         Attachments: HIVE-3733.1.patch.txt, HIVE-3733.3.patch.txt, HIVE-3733.4.patch.txt
>
>
> If the config hive.merge.mapfiles is set to true and hive.merge.mapredfiles is set to
false then when hive encounters a FileSinkOperator when generating map reduce tasks, it will
look at the entire job to see if it has a reducer, if it does it will not merge. Instead it
should be check if the FileSinkOperator is a child of the reducer. This means that outputs
generated in the mapper will be merged, and outputs generated in the reducer will not be,
the intended effect of setting those configs.
> Simple repro:
> set hive.merge.mapfiles=true;
> set hive.merge.mapredfiles=false;
> EXPLAIN
> FROM <input_table>
> INSERT OVERWRITE TABLE <output_table1> SELECT key, COUNT(*) group by key
> INSERT OVERWRITE TABLE <output_table2> SELECT *;
> The output should contain a Conditional Operator, Mapred Stages, and Move tasks

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Mime
View raw message