Re: Postgres memory usage

On Sep 16, 2004, at 8:58 AM, ruben20@superguai.com wrote:

> I have noticed that available memory is aparently too low, according
> to top:
>
>  12:58pm  up  1:28,  3 users,  load average: 0,00, 0,01, 0,09
> 94 processes: 91 sleeping, 3 running, 0 zombie, 0 stopped
> CPU states:  0,0% user,  0,0% system,  0,0% nice, 100,0% idle
> Mem:  1031012K av, 1021440K used,    9572K free,       0K shrd,
> 62864K
> buff
> Swap: 2040244K av,   14960K used, 2025284K free
> 876808K
> cached
>

in the unix world, "free" memory is mostly useless because the OS will
give up various buffers it is using for caching if an app needs memory.
  It is usually best to look at the output of free which will show you
how much of the memory is used by buffers & caches.

If that number is also low you should look to see how much memory your
applications are using.

Also, what are your shared_buffer and sort_mem settings set to in
postgresql.conf?
Remember in Linux top will include how much shared memory an app has
touched in its SIZE. (But you can also look at the shared column to see
how much of hte size is shared)
.


--
Jeff Trout <jeff@jefftrout.com>
http://www.jefftrout.com/
http://www.stuarthamm.net/