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From "Zhenxiao Luo (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (HIVE-3467) BucketMapJoinOptimizer should optimize joins on partition columns
Date Mon, 10 Dec 2012 07:33:22 GMT

     [ https://issues.apache.org/jira/browse/HIVE-3467?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Zhenxiao Luo updated HIVE-3467:
-------------------------------

    Attachment: HIVE-3467.3.patch.txt
    
> BucketMapJoinOptimizer should optimize joins on partition columns
> -----------------------------------------------------------------
>
>                 Key: HIVE-3467
>                 URL: https://issues.apache.org/jira/browse/HIVE-3467
>             Project: Hive
>          Issue Type: Bug
>          Components: Query Processor
>    Affects Versions: 0.10.0
>            Reporter: Kevin Wilfong
>            Assignee: Zhenxiao Luo
>         Attachments: HIVE-3467.1.patch.txt, HIVE-3467.2.patch.txt, HIVE-3467.3.patch.txt
>
>
> Consider the query:
> SELECT * FROM t1 JOIN t2 on t1.part = t2.part and t1.key = t2.key;
> Where t1 and t2 are partitioned by part and bucketed by key.
> Suppose part take values 1 and 2 and t1 and t2 are bucketed into 2 buckets.
> The bucket map join optimizer will put the first bucket of part=1 and part=2 partitions
of t2 into the same mapper as that of part=1 partition of t1.  It will do the same for the
part=2 partition of t1.
> It could take advantage of the partition values and send the first bucket of only the
part=1 partitions of t1 and t2 into one mapper and the first bucket of only the part=2 partitions
into another.

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