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From "Mike Matrigali (JIRA)" <j...@apache.org>
Subject [jira] [Created] (DERBY-6226) enhance optmizer to use multiple probes into multiple indexes to satisfy OR queries on different columns.
Date Thu, 23 May 2013 22:17:21 GMT
Mike Matrigali created DERBY-6226:
-------------------------------------

             Summary: enhance optmizer to use multiple probes into multiple indexes to satisfy
OR queries on different columns.
                 Key: DERBY-6226
                 URL: https://issues.apache.org/jira/browse/DERBY-6226
             Project: Derby
          Issue Type: Improvement
          Components: SQL
    Affects Versions: 10.8.3.1, 10.11.0.0
            Reporter: Mike Matrigali


For queries of the type:

select * from a where col1 = ? or col2 = ?
and good indexes exist on col1 and col2 it would optimal if derby could execute a plan that
did an index scan first on the col1 index and then an index scan on col2 index.  
Currently it looks like derby will do a full index scan if col1 and col2 are in any index,
or a full table
scan otherwise.

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