You are viewing a plain text version of this content. The canonical link for it is here.

Posted to dev@pig.apache.org by "Daniel Dai (JIRA)" <ji...@apache.org> on 2011/03/14 23:41:29 UTC

[jira] Updated: (PIG-483) PERFORMANCE: different strategies for large and small order bys

     [ https://issues.apache.org/jira/browse/PIG-483?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Daniel Dai updated PIG-483:
---------------------------

    Description: 
Currently pig always does a multi-pass order by where it first determines a distribution for the keys and then orders in a second pass.  This avoids the necessity of having a single reducer.  However, in cases where the data is small enough to fit into a single reducer, this is inefficient.  For small data sets it would be good to realize the small size of the set and do the order by in a single pass with a single reducer.

This is a candidate project for Google summer of code 2011. More information about the program can be found at http://wiki.apache.org/pig/GSoc2011

  was:Currently pig always does a multi-pass order by where it first determines a distribution for the keys and then orders in a second pass.  This avoids the necessity of having a single reducer.  However, in cases where the data is small enough to fit into a single reducer, this is inefficient.  For small data sets it would be good to realize the small size of the set and do the order by in a single pass with a single reducer.

         Labels: gsoc2011  (was: )

> PERFORMANCE: different strategies for large and small order bys
> ---------------------------------------------------------------
>
>                 Key: PIG-483
>                 URL: https://issues.apache.org/jira/browse/PIG-483
>             Project: Pig
>          Issue Type: Improvement
>    Affects Versions: 0.2.0
>            Reporter: Olga Natkovich
>              Labels: gsoc2011
>
> Currently pig always does a multi-pass order by where it first determines a distribution for the keys and then orders in a second pass.  This avoids the necessity of having a single reducer.  However, in cases where the data is small enough to fit into a single reducer, this is inefficient.  For small data sets it would be good to realize the small size of the set and do the order by in a single pass with a single reducer.
> This is a candidate project for Google summer of code 2011. More information about the program can be found at http://wiki.apache.org/pig/GSoc2011

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira