Re: Shared_buffers hint

Hi Rafael,

The result there means that the minimal should be 4.69Mb for
shared_buffers
As a rule of thumb the shared buffers should be between 10% - 15% of
available RAM that assuming such is a dedicated PG server.
I have worked on some servers where I set shared buffers lower than
10%, it's really a matter of trying out what value works best for you.

Marcelo
Linux/Solaris System Administrator
http://www.zeroaccess.org

On Oct 6, 2008, at 6:52 AM, Rafael Domiciano wrote:

> HI people,
>
> I'm tuning a server that is a long time abandoned, and this server
> is a little slow.
> Now, in my postgresql.conf I have:
> shared_buffers = 100Mb
> mas_fsm_relations = 15000
> mas_fsm_pages = 1600000
> max_connections = 300
>
> And I changin' to:
> shared_buffers = 1000Mb
> (The server has 2 Gb of memory)
> mas_fsm_relations = 15000
> (The Vacuum noticed me 608 relations)
> mas_fsm_pages = 1600000
> (The Vacuum noticed me 500800 pages)
> max_connections = 300
> (I did a "ps axf | grep postgres | wc -l" and the bash brings to
> me the number of 120 and all the people is not online at now)
>
> My qustion is about shared_buffers, in postgresql.conf I have: min
> 128kB or max_connections*16kB # (change requires restart)
> So I did:
> 300 * (16Kb / 1024) = 4,69?
> What this result means?
>
> Thnks all,
>
> Rafael Domiciano