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From "Namit Jain (JIRA)" <>
Subject [jira] [Created] (HIVE-3639) join order across mutiple joins
Date Tue, 30 Oct 2012 07:12:24 GMT
Namit Jain created HIVE-3639:

             Summary: join order across mutiple joins
                 Key: HIVE-3639
             Project: Hive
          Issue Type: Improvement
          Components: Query Processor
            Reporter: Namit Jain

This came up during a discussion with Sambavi - please add any details I may
have missed.

For a query of the form:

select ..
A join B on A.c1 = B.c1
join C on B.c2=C.c2;

A,B are joined first and the result is then joined with C.
This is clearly sub-optimal if A is the largest table, in which case
B and C should be joined first, and then the result should be joined with A.

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