From: Michael Monnerie <michael.monnerie@it-management.at>
To: pgsql-admin@postgresql.org
Subject: Re: confused of buffers and memory settings
Date: Wed, 23 Apr 2008 13:19:23 +0200
Message-ID: <200804231319.24090@zmi.at> (raw)
In-Reply-To: <480F0C92.8050907@transporeon.com>
References: <480F0C92.8050907@transporeon.com>
On Mittwoch, 23. April 2008 Gerd König wrote:
> The db will be accessed heavily (~20 requests/sec.)
> with a read/write ration of 50:50, yes, a lot of write activity.
Not really heavy, I would say, but maybe your transactions are very big
and produce a lot of I/O.
> I thought of setting "shared_buffers" to 750000 (~6GB) but how
> depends this on the kernel buffer setting in /etc/sysctl.conf (what
> is the interaction between these two settings?).
> I know the variable "shmmax" can be defined, but currently there's no
> such entry.
# Shared Mem Maximum example:
kernel.shmmax = 950123456
# do not allow memory overcommit to prevent database crashes
vm.overcommit_memory=2
> The meaning of "work_mem" / "maintenance_work_mem" and "wal_buffers"
> is also not clear. The maintenance_work_mem influences the size of
> the WAL logs..?!?
> What else are "top performance related" options for the usage
> scenario I described earlier ?
http://www.postgresql.org/docs/8.3/interactive/runtime-config-resource.html
mfg zmi
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To: pgsql-admin@postgresql.org
Cc: michael.monnerie@it-management.at
Subject: Re: confused of buffers and memory settings
In-Reply-To: <200804231319.24090@zmi.at>
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