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From "Rick Hillegas (JIRA)" <j...@apache.org>
Subject [jira] Created: (DERBY-4327) Implement optimizer support for bushy trees.
Date Wed, 29 Jul 2009 13:06:14 GMT
Implement optimizer support for bushy trees.
--------------------------------------------

                 Key: DERBY-4327
                 URL: https://issues.apache.org/jira/browse/DERBY-4327
             Project: Derby
          Issue Type: Improvement
          Components: SQL
            Reporter: Rick Hillegas


Currently, the optimizer only considers left-deep trees. For queries involving many tables,
the best plan may be bushy. In this email thread, a user notes poor performance by Derby on
queries involving 5 or more tables: http://www.nabble.com/Slow-performance-on-5-or-more-joins-in-a-star-schema-tt24708686.html

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