Thread: postgresql not using enough memory?

Hello list,

I know this is a complicated issue, but I'll throw it out there...
Our DB box has 3GB of ram - which is supposed to be used by
postgres.  Whenever I use top, it only shows about 800MB being
used with 2.2GB free.  What can I do to tell postgres to use more
of that memory - maybe 2GB ?

I am running on fedora core 1.  as far as my postgrsql.conf file, here's
the related settings:

vacuum_mem = 16384
max_fsm_pages = 32001
max_fsm_relations = 2000
max_files_per_process = 10000
effective_cache_size = 100000

Also, in my /etc/sysctl.conf file, I have these lines:

# added to allow a single app to have 512MB
kernel.shmall = 536870912
kernel.shmmax = 536870912

Any ideas?

Thanks,
Devin

Oops! admin@usachurch.com was seen spray-painting on a wall:
> Hello list,
>
> I know this is a complicated issue, but I'll throw it out there...
> Our DB box has 3GB of ram - which is supposed to be used by
> postgres.  Whenever I use top, it only shows about 800MB being
> used with 2.2GB free.  What can I do to tell postgres to use more
> of that memory - maybe 2GB ?

The one change that might be appropriate would be to bump up sort
memory.  Not too much; 40MB is a terrifically large amount unless
you're doing REALLY enormous sorts.

Aside from that, it is quite likely that everything is AOK.
PostgreSQL benefits from having data in the filesystem cache, and if
you up the shared buffer cache, you risk having the commonly-used data
stored twice, once in the buffer cache, and once in the filesystem
cache, which is wasteful.
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