Re: multicolumn index column order
| От | valgog | 
|---|---|
| Тема | Re: multicolumn index column order | 
| Дата | |
| Msg-id | 1185352440.504985.282370@19g2000hsx.googlegroups.com обсуждение исходный текст | 
| Ответ на | Re: multicolumn index column order ("Valentine Gogichashvili" <valgog@gmail.com>) | 
| Ответы | Re: multicolumn index column order | 
| Список | pgsql-performance | 
On Jul 25, 2:14 am, Lew <l...@lewscanon.nospam> wrote: > > How about two indexes, one on each column? Then the indexes will cooperate > when combined in a WHERE clause. > <http://www.postgresql.org/docs/8.2/interactive/indexes-bitmap-scans.html> > > I don't believe the index makes a semantic difference with regard to ascending > or descending. An index is used to locate records in the selection phase of a > query or modification command. > > -- > Lew Ordered indexes (b-tree in this case) are also used to get the needed record order and it is absolutely not necessary to have a WHARE clause in your select statement to use them when you are using ORDER BY. -- Valentine
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