Re: To increase RAM or not

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From: pgsql-general-owner(at)postgresql(dot)org [mailto:pgsql-general-owner(at)postgresql(dot)org] On Behalf Of Emanuel Calvo
Sent: Wednesday, October 22, 2014 10:39 AM
To: pgsql-general(at)postgresql(dot)org
Subject: Re: [GENERAL] To increase RAM or not

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El 22/10/14 a las 02:37, Nikhil Daddikar escibió:
> Folks,
>
> I have set about 12GB RAM (shared buffers) for our Postgresql
> instance. How do I know if this is actually being used? And is there a
> way to know by how much should I increase it, if it is not enough?
>
> Thanks.
>

That's a lot if you are using the latest version.

There are several links and blogs related on this, here you have some I found quickly:
http://rhaas.blogspot.com.es/2012/03/tuning-sharedbuffers-and-walbuffers.html

http://www.depesz.com/2012/06/09/how-much-ram-is-postgresql-using/

Try to filter those which are quite old if you don't want to mess up with configuration variables like max_fsm_pages, etc.

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Emanuel Calvo http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services Bs. As., Argentina (GMT-3) -----BEGIN PGP SIGNATURE-----
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Comment: GPGTools - http://gpgtools.org

Here is couple great recent posts by Keith Fiske that help answering your question:

http://www.keithf4.com/a-small-database-does-not-mean-small-shared_buffers/

http://www.keithf4.com/a-large-database-does-not-mean-large-shared_buffers/#comment-945

Regards,
Igor Neyman