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From "Maryann Xue (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (PHOENIX-16) Join Query optimization
Date Fri, 31 Jan 2014 03:18:08 GMT

    [ https://issues.apache.org/jira/browse/PHOENIX-16?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13887418#comment-13887418
] 

Maryann Xue commented on PHOENIX-16:
------------------------------------

The below query should work.
       select * from t1 inner join t2 on t1.col1 = t2.col2 and t2.id < 1000 where t1.id
< 1000

This is actually an optimization to be done, for in the original query "t2.id < 1000" could
have been recognized as a pre-filter, but in a more general case, this would take more check
and should be handled more carefully.

> Join Query optimization
> -----------------------
>
>                 Key: PHOENIX-16
>                 URL: https://issues.apache.org/jira/browse/PHOENIX-16
>             Project: Phoenix
>          Issue Type: Improvement
>    Affects Versions: 3.0.0
>            Reporter: abhishek
>            Assignee: Maryann Xue
>
> select * from t1 inner join t2 on t1.col1 = t2.col2 where t1.id < 1000 and t2.id <
1000
> For above query, phoenix first join the tables t1 and t2, and then apply the filter t1.id
< 1000 and t2.id < 1000. This is very inefficient. This can be easily fixed by pushing
the filter operation before the join query.



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