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Date: Fri, 9 Apr 2010 10:44:59 -0600
Message-ID: <r2ydcc563d11004090944vdee233a7w4dbf3ea99217005c@mail.gmail.com>
Subject: Re: PostgreSQL with Zabbix - problem of newbe
From: Scott Marlowe <scott.marlowe@gmail.com>
To: Merlin Moncure <mmoncure@gmail.com>
Cc: Greg Smith <greg@2ndquadrant.com>, Krzysztof Kardas <krzychk2@gmail.com>,
	pgsql-performance@postgresql.org
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On Fri, Apr 9, 2010 at 10:30 AM, Merlin Moncure <mmoncure@gmail.com> wrote:
> On Fri, Apr 9, 2010 at 12:03 PM, Greg Smith <greg@2ndquadrant.com> wrote:
>> The main problem with this configuration is that work_mem is set to an
>> unsafe value--1.6GB. =A0With potentially 400 connections and about 2GB o=
f RAM
>> free after starting the server, work_mem=3D'4MB' is as large as you can =
safely
>> set this.
>
> if you need more work_mem for this or that and also need to serve a
> lot of connections, you can always set it locally (1.6GB is still too
> high though -- maybe 64mb if you need to do a big sort or something
> like that).
>
> Another path to take is to install pgbouncer, which at 400 connections
> is worth considering -- but only if your client stack doesn't use
> certain features that require a private database session. =A0zabbix will
> _probably_ work because it is db portable software (still should check
> however).

Also remember you can set it by user or by db, depending on your
needs.  I had a server that had a reporting db and an app db.  The app
db was set to 1 or 2 Meg work_mem, and the reporting db that had only
one or two threads ever run at once was set to 128Meg.  Worked
perfectly for what we needed.