Re: Index not being used in MAX function (7.2.3)
От | Bruno Wolff III |
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Тема | Re: Index not being used in MAX function (7.2.3) |
Дата | |
Msg-id | 20030613205813.GA20982@wolff.to обсуждение исходный текст |
Ответ на | Re: Index not being used in MAX function (7.2.3) ("Jim C. Nasby" <jim@nasby.net>) |
Ответы |
Re: Index not being used in MAX function (7.2.3)
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Список | pgsql-general |
On Fri, Jun 13, 2003 at 15:12:39 -0500, "Jim C. Nasby" <jim@nasby.net> wrote: > On Fri, Jun 13, 2003 at 10:37:46AM -0500, Bruno Wolff III wrote: > > On Thu, Jun 12, 2003 at 17:26:11 -0500, > > "Jim C. Nasby" <jim@nasby.net> wrote: > > > On Thu, Jun 12, 2003 at 12:08:15PM +0800, Ang Chin Han wrote: > > > > > > This becomes really important whenever pgsql gains the ability to use > > > multiple indexes per table (someone smack me if it can do this now and I > > > > SMACK! > > You can use multiple indexes per query plan node? IE: if you have > indexes on a and b, you can use both indexes when you do WHERE a=blah > and b=foo? That's what I was reffering to... I think what you are describing doesn't make much sense. On any scan you are only going to using one index (possibly over several columns). But while processing a query you might be making use of several indexes on a table. For example the following query should would fast if appropiate indexes exist: select (select col1 from tab order by col1), (select col2 from tab order by col2)
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