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From "Namit Jain (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (HIVE-3763) Aggregation followed by a sort-merge join requires a new MR job
Date Fri, 14 Dec 2012 06:24:12 GMT

     [ https://issues.apache.org/jira/browse/HIVE-3763?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Namit Jain updated HIVE-3763:
-----------------------------

    Status: Patch Available  (was: Open)
    
> Aggregation followed by a sort-merge join requires a new MR job
> ---------------------------------------------------------------
>
>                 Key: HIVE-3763
>                 URL: https://issues.apache.org/jira/browse/HIVE-3763
>             Project: Hive
>          Issue Type: Bug
>            Reporter: Namit Jain
>            Assignee: Namit Jain
>
> After Hive-3633, if tbl1 and tbl2 are tables bucketiezed and sorted by key into 2 buckets,
the following query:
> 	
> 	
> select count(*) from (	
>   select /*+mapjoin(a)*/ a.key as key, a.value as val1, b.value as val2 from tbl1 a join
tbl2 b on a.key = b.key
> ) subq1;	
> requires 2 MR job - the first one is a sort-merge join, and the second MR job
> performs the count(*) on the output of the sort-merge join. 
> Ideally, this should be performed in a single MR job.

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