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Message Posted: Wed, 25 Jul 2007 @ 10:53:42 GMT
Subj: | | Re: MAX vs rank-qualify |
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From: | | Anomy Anom |
<-- Anonymously Posted: Tuesday, July 24, 2007 22:19 -->
Thanks Barry and Deiter for your insights.
@Barry:
| The OLAP functions will always redistribute the qualifying rows of the table by values (based on partition and order by clause). The
normal aggregate functions can avoid a redistribution if the primary index columns are the same or a subset of the columns that you're using in
your "GROUP BY" clause. | |
For the case of the OLAP function, does the redistribution happen even when the primary index columns are a subset of the partition by columns
(when it shouldnt be logically speaking?) The explain does not take me any near to the answer because the explain only states "is assumed to be
redistributed by value to all AMPs"
Regards
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