Re: Sorting a query on a view ignores an index
От | Mathieu De Zutter |
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Тема | Re: Sorting a query on a view ignores an index |
Дата | |
Msg-id | 20030821162448.GC973@pleyel.kotnet.org обсуждение исходный текст |
Ответ на | Re: Sorting a query on a view ignores an index (Tom Lane <tgl@sss.pgh.pa.us>) |
Ответы |
Re: Sorting a query on a view ignores an index
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Список | pgsql-performance |
On Thu, Aug 21, 2003 at 10:59:11AM -0400, Tom Lane wrote: > Mathieu De Zutter <mathieu@dezutter.org> writes: > > However, i dont want the view to be presorted, but sort it in the > > queries that use the view. When I do that, the index I have on that > > field seems to be ignored. It stretches so far that, when I sort the > > view on A and sort the query on A too, the query will try to sort > > _again_ _without_ index and thus lose all performance. > > This is a limitation of the 7.3 query planner. 7.4 should do better. Ok I'll have to live with that I guess. Apart from avoiding views or subselects when sorting afterwards and putting the whole bunch in a huge SQL statement (which i'll have to produce on-the-fly), do you have an other alternative? The 2 seconds is way to much, as the database will eventually run on a machine that is 10 times slower. With kind regards, Mathieu
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