Thread: FW: Performance 8.4.0
The database is 8gb currently. Use to be a lot bigger but we removed all large objects out and developed a file server storagefor it, and using default page costs for 8.4, I did have it changed in 8.1.4 -----Original Message----- From: Robert Haas [mailto:robertmhaas@gmail.com] Sent: Sunday, 2 August 2009 11:26 PM To: Chris Dunn Cc: pgsql-performance@postgresql.org Subject: Re: [PERFORM] Performance 8.4.0 On Fri, Jul 31, 2009 at 12:22 AM, Chris Dunn<chris.dunn@bigredsky.com> wrote: > constraint_exclusion = on This is critical if you need it, but a waste of CPU time if you don't. Other than that your paramaters look good. Are you using the default page cost settings? I see you have 12 GB RAM; how big is your database? ...Robert
On Sun, Aug 2, 2009 at 10:04 PM, Chris Dunn<chris.dunn@bigredsky.com> wrote: > The database is 8gb currently. Use to be a lot bigger but we removed all large objects out and developed a file serverstorage for it, and using default page costs for 8.4, I did have it changed in 8.1.4 You might want to play with lowering them. The default page costs make page accesses expensive relative to per-tuple operations, which is appropriate if you are I/O-bound but not so much if you are CPU bound, and especially if the whole database is memory resident. I'd try something like random_page_cost = seq_page_cost = 0.1 for starters, or whatever values were working for you in 8.1, but the sweet spot may be higher or lower. ...Robert