Re: [PERFORM] effective_cache_size on 32-bits postgres

2013-03-18 Thread Rodrigo Barboza
Yes, Claudio. You got it. But Rob seems to have already answered the confusion between 32 and 64 bits for effective_cache_size. Actually I am creating generic configuration based on physical memory. So I wanna be conservative about effective_cache_size. That's why I'm following postgres tuning webs

Re: [PERFORM] effective_cache_size on 32-bits postgres

2013-03-18 Thread Pavel Stehule
2013/3/18 Kevin Grittner : > Rodrigo Barboza wrote: > >> So setting this as half of ram, as suggested in postgres tuning >> webpage should be safe? > > Half of RAM is likely to be a very bad setting for any work load. > It will tend to result in the highest possible number of pages > duplicated in

Re: [PERFORM] effective_cache_size on 32-bits postgres

2013-03-18 Thread Claudio Freire
On Mon, Mar 18, 2013 at 3:47 PM, Kevin Grittner wrote: > Rodrigo Barboza wrote: > >> So setting this as half of ram, as suggested in postgres tuning >> webpage should be safe? > > Half of RAM is likely to be a very bad setting for any work load. > It will tend to result in the highest possible nu

Re: [PERFORM] effective_cache_size on 32-bits postgres

2013-03-18 Thread Kevin Grittner
Rodrigo Barboza wrote: > So setting this as half of ram, as suggested in postgres tuning > webpage should be safe? Half of RAM is likely to be a very bad setting for any work load. It will tend to result in the highest possible number of pages duplicated in PostgreSQL and OS caches, reducing th

Re: [PERFORM] effective_cache_size on 32-bits postgres

2013-03-18 Thread Pavel Stehule
2013/3/18 Rodrigo Barboza : > So setting this as half of ram, as suggested in postgres tuning webpage > should be safe? > It says it is a conservative value... depends how much memory is used as cache ?? it can be a shared_buffers + file system cache Regards Pavel Stehule > > > On Mon, Mar 18,

Re: [PERFORM] effective_cache_size on 32-bits postgres

2013-03-18 Thread Rodrigo Barboza
So setting this as half of ram, as suggested in postgres tuning webpage should be safe? It says it is a conservative value... On Mon, Mar 18, 2013 at 3:18 PM, Pavel Stehule wrote: > 2013/3/18 Pavel Stehule : > > Hello > > > > 2013/3/18 Rodrigo Barboza : > >> Hi guys, I am worried about the effec

Re: [PERFORM] effective_cache_size on 32-bits postgres

2013-03-18 Thread Pavel Stehule
2013/3/18 Pavel Stehule : > Hello > > 2013/3/18 Rodrigo Barboza : >> Hi guys, I am worried about the effective_cache_size. >> I run a 32-bits postgres installation on a machine with 64 bits kernel. >> Should I limit effective_cache_size to a maximum of 2.5gb? > > sure and probably little bit less

Re: [PERFORM] effective_cache_size on 32-bits postgres

2013-03-18 Thread Rodrigo Barboza
Ok, now I'm lost, who is right about the limit? Rob or Pavel? Rob, I know it should be a 64 bit, and it will be soon, but there are good reasons for this scenario and it's ok for now. On Mon, Mar 18, 2013 at 3:15 PM, Pavel Stehule wrote: > Hello > > 2013/3/18 Rodrigo Barboza : > > Hi guys, I am

Re: [PERFORM] effective_cache_size on 32-bits postgres

2013-03-18 Thread Pavel Stehule
Hello 2013/3/18 Rodrigo Barboza : > Hi guys, I am worried about the effective_cache_size. > I run a 32-bits postgres installation on a machine with 64 bits kernel. > Should I limit effective_cache_size to a maximum of 2.5gb? sure and probably little bit less Regards Pavel -- Sent via pgsql-p

Re: [PERFORM] effective_cache_size on 32-bits postgres

2013-03-18 Thread Rob Wultsch
On Mon, Mar 18, 2013 at 10:53 AM, Rodrigo Barboza wrote: > Hi guys, I am worried about the effective_cache_size. > I run a 32-bits postgres installation on a machine with 64 bits kernel. > Should I limit effective_cache_size to a maximum of 2.5gb? That variables refers to fs cache, so 32 bit pg s

[PERFORM] effective_cache_size on 32-bits postgres

2013-03-18 Thread Rodrigo Barboza
Hi guys, I am worried about the effective_cache_size. I run a 32-bits postgres installation on a machine with 64 bits kernel. Should I limit effective_cache_size to a maximum of 2.5gb?