Re: Question on COUNT performance
| От | Reinoud van Leeuwen |
|---|---|
| Тема | Re: Question on COUNT performance |
| Дата | |
| Msg-id | 20100714134410.GK62243@spoetnik.xs4all.nl обсуждение исходный текст |
| Ответ на | Re: Question on COUNT performance (Joshua Tolley <eggyknap@gmail.com>) |
| Список | pgsql-sql |
On Wed, Jul 14, 2010 at 07:30:39AM -0600, Joshua Tolley wrote: > > Have you tried 'select count (1)..."? > > If this helps at all, it's unlikely to help much. I remember having seen > discussion somewhere that there's an optimization such that count(*) and > count(1) do the same thing anyway, but I can't find it in the code > immediately. oops, I was thinking too much about Sybase (where is makes a huge difference, since the optimiser sees that everything it needs can be found in the index so the table does not have to be read at all). Reinoud -- __________________________________________________ "Nothing is as subjective as reality" Reinoud van Leeuwen reinoud.v@n.leeuwen.net http://reinoud.van.leeuwen.net kvk 27320762 __________________________________________________
В списке pgsql-sql по дате отправления: