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From "Dag H. Wanvik (JIRA)" <j...@apache.org>
Subject [jira] [Created] (DERBY-6335) Improve performance of FETCH NEXT/OFFSET with ORDER BY
Date Thu, 05 Sep 2013 13:44:53 GMT
Dag H. Wanvik created DERBY-6335:
------------------------------------

             Summary: Improve performance of FETCH NEXT/OFFSET with ORDER BY
                 Key: DERBY-6335
                 URL: https://issues.apache.org/jira/browse/DERBY-6335
             Project: Derby
          Issue Type: Improvement
          Components: SQL
            Reporter: Dag H. Wanvik


We can utilize information about the number of rows to be retrieved to

a) optimize any sorting imposed by the ORDER BY by keeping only the top <next> rows
in memory,
b) inform the optimizer with more precise information about the number of rows in those cases
where such a constrict is a join participant.

For b) this would only work if <next> were known statically at compile time. For a)
this could work even with ? parameters,



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