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From "Rick Hillegas (JIRA)" <j...@apache.org>
Subject [jira] Commented: (DERBY-2998) Add support for ROW_NUMBER() window function
Date Fri, 18 Jan 2008 21:18:34 GMT

    [ https://issues.apache.org/jira/browse/DERBY-2998?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12560547#action_12560547
] 

Rick Hillegas commented on DERBY-2998:
--------------------------------------

Thanks for the explanation of the problem, Thomas. I am still a bit puzzled, however. You
have sketched the shape of the BestPlan produced by the optimizer, as seen before generate()
is run on the plan. Could you show us the ExecutablePlan as well?

Off the top of my head, at execution time, the sort ought to be happening beneath the WindowResultSet
in the ExecutablePlan. It, however, sounds as though the row_number column has been pushed
down into the ResultSet that the sorter is operating on. That sounds wrong to me. The row_number
column should only appear in the top ResultSet generated from the top level PRN in the plan
you sketched.

Thanks,
-Rick

> Add support for ROW_NUMBER() window function
> --------------------------------------------
>
>                 Key: DERBY-2998
>                 URL: https://issues.apache.org/jira/browse/DERBY-2998
>             Project: Derby
>          Issue Type: Sub-task
>          Components: SQL
>            Reporter: Thomas Nielsen
>            Assignee: Thomas Nielsen
>            Priority: Minor
>         Attachments: d2998-4.diff, d2998-4.stat, d2998-5.diff, d2998-5.stat, d2998-6.diff,
d2998-6.stat, d2998-7.diff, d2998-7.stat, d2998-8.diff, d2998-8.stat, d2998-doc-1.diff, d2998-doc-1.stat,
d2998-test.diff, d2998-test.stat, d2998-test2.diff, d2998-test2.stat, d2998-test3.diff, d2998-test3.stat
>
>
> As part of implementing the overall OLAP Operations features of SQL (DERBY-581), implement
the ROW_NUMBER() window function.
> More information about this feature is available at http://wiki.apache.org/db-derby/OLAPRowNumber

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