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From "Namit Jain (JIRA)" <j...@apache.org>
Subject [jira] [Created] (HIVE-3763) Aggregation followed by a sort-merge join requires a new MR job
Date Mon, 03 Dec 2012 05:39:58 GMT
Namit Jain created HIVE-3763:
--------------------------------

             Summary: 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


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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