hive-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Navis (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HIVE-2340) optimize orderby followed by a groupby
Date Tue, 05 Feb 2013 00:58:18 GMT

    [ https://issues.apache.org/jira/browse/HIVE-2340?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13570813#comment-13570813
] 

Navis commented on HIVE-2340:
-----------------------------

@Gunther Hagleitner: I also considered ratio thing, but number of reducers is calculated based
on input size just before submitted to hadoop and cannot be known in optimizer layer. 
Except those special cases with order by and bucketing, number of reducers for both RS is
-1. So generally speaking, it's safe.
                
> optimize orderby followed by a groupby
> --------------------------------------
>
>                 Key: HIVE-2340
>                 URL: https://issues.apache.org/jira/browse/HIVE-2340
>             Project: Hive
>          Issue Type: Sub-task
>          Components: Query Processor
>            Reporter: Navis
>            Assignee: Navis
>            Priority: Minor
>              Labels: perfomance
>         Attachments: ASF.LICENSE.NOT.GRANTED--HIVE-2340.D1209.1.patch, ASF.LICENSE.NOT.GRANTED--HIVE-2340.D1209.2.patch,
ASF.LICENSE.NOT.GRANTED--HIVE-2340.D1209.3.patch, ASF.LICENSE.NOT.GRANTED--HIVE-2340.D1209.4.patch,
ASF.LICENSE.NOT.GRANTED--HIVE-2340.D1209.5.patch, HIVE-2340.1.patch.txt, HIVE-2340.D1209.10.patch,
HIVE-2340.D1209.6.patch, HIVE-2340.D1209.7.patch, HIVE-2340.D1209.8.patch, HIVE-2340.D1209.9.patch,
testclidriver.txt
>
>
> Before implementing optimizer for JOIN-GBY, try to implement RS-GBY optimizer(cluster-by
following group-by).

--
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