The recommendation for effective_cache_size is about 2/3 of your server's physical RAM (if the server is dedicated only for postgres). This should have a significant impact on whether Postgres planner chooses indexes over sequential scans.
-- Husam -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jean-Pierre Pelletier Sent: Thursday, September 22, 2005 4:10 PM To: josh@agliodbs.com Cc: pgsql-performance@postgresql.org Subject: Re: [PERFORM] Queries 15 times slower on 8.1 beta 2 than on 8.0 my settings are: effective_cache_size = 1000 random_page_cost = 4 work_mem = 20000 ----- Original Message ----- From: "Josh Berkus" <josh@agliodbs.com> To: "Jean-Pierre Pelletier" <[EMAIL PROTECTED]> Sent: Thursday, September 22, 2005 6:58 PM Subject: Re: [PERFORM] Queries 15 times slower on 8.1 beta 2 than on 8.0 > Jean-Pierre, > >> How do I produce an "Index scan plan" ? > > You just did. What's your effective_cache_size set to? > random_page_cost? work_mem? > > -- > --Josh > > Josh Berkus > Aglio Database Solutions > San Francisco ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq ********************************************************************** This message contains confidential information intended only for the use of the addressee(s) named above and may contain information that is legally privileged. If you are not the addressee, or the person responsible for delivering it to the addressee, you are hereby notified that reading, disseminating, distributing or copying this message is strictly prohibited. If you have received this message by mistake, please immediately notify us by replying to the message and delete the original message immediately thereafter. Thank you. FADLD Tag ********************************************************************** ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org
