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From "Navis (JIRA)" <j...@apache.org>
Subject [jira] [Created] (HIVE-3972) Support using multiple reducer for fetching order by results
Date Fri, 01 Feb 2013 07:45:13 GMT
Navis created HIVE-3972:
---------------------------

             Summary: Support using multiple reducer for fetching order by results
                 Key: HIVE-3972
                 URL: https://issues.apache.org/jira/browse/HIVE-3972
             Project: Hive
          Issue Type: Improvement
          Components: Query Processor
            Reporter: Navis
            Assignee: Navis
            Priority: Minor


Queries for fetching results which have lastly "order by" clause make final MR run with single
reducer, which can be too much. For example, 
{code}
select value, sum(key) as sum from src group by value order by sum;
{code}
If number of reducer is reasonable, multiple result files could be merged into single sorted
stream in the fetcher level.

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