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https://issues.apache.org/jira/browse/HIVE-1194?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12839932#action_12839932
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He Yongqiang commented on HIVE-1194:
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yes, we can do that. there are two problems need to resolve;
(1) serialize and deserialize the mapping. We generate the mapping at compile
time, and the operator instance is different then the one in runtime.
(2) the fetchOperators need to be accessed in SMBMapJoinOperator. need to pass
these from exec-mapper to SMBMapJoinOperator
I just made a small changes,
i added a new method initializeLocalWork() in Operator. In exec-mapper, the
mapoperator's initializeLocalWork() is called, and triggered all its children's
initializeLocalWork().
> sorted merge join
> -----------------
>
> Key: HIVE-1194
> URL: https://issues.apache.org/jira/browse/HIVE-1194
> Project: Hadoop Hive
> Issue Type: New Feature
> Components: Query Processor
> Reporter: Namit Jain
> Assignee: He Yongqiang
> Fix For: 0.6.0
>
> Attachments: hive-1194-2010-02-28.patch
>
>
> If the input tables are sorted on the join key, and a mapjoin is being
> performed, it is useful to exploit the sorted properties of the table.
> This can lead to substantial cpu savings - this needs to work across bucketed
> map joins also.
> Since, sorted properties of a table are not enforced currently, a new
> parameter can be added to specify to use the sort-merge join.
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