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Posted to dev@hive.apache.org by "Namit Jain (JIRA)" <ji...@apache.org> on 2012/12/03 06:39:58 UTC
[jira] [Created] (HIVE-3763) Aggregation followed by a sort-merge
join requires a new MR job
Namit Jain created HIVE-3763:
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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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