From: Stephen Frost <sfrost@snowman.net>
To: Claudio Freire <klaussfreire@gmail.com>
Cc: Igor Chudov <ichudov@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Postgres for a "data warehouse", 5-10 TB
Date: Sun, 11 Sep 2011 22:29:26 -0400
Message-ID: <20110912022926.GP12765@tamriel.snowman.net> (raw)
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* Claudio Freire (klaussfreire@gmail.com) wrote:
> I don't think you'd want that. Remember, work_mem is the amount of
> memory *per sort*.
> Queries can request several times that much memory, once per sort they
> need to perform.
>
> You can set it really high, but not 60% of your RAM - that wouldn't be wise.
Oh, I dunno.. It's only used by the planner, so sometimes you have to
bump it up, especially when PG thinks the number of rows returned from
something will be a lot more than it really will be. :)
/me has certain queries where it's been set to 100GB... ;)
I agree that it shouldn't be the default, however. That's asking for
trouble. Do it for the specific queries that need it.
Thanks,
Stephen
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To: pgsql-performance@postgresql.org
Cc: sfrost@snowman.net, klaussfreire@gmail.com, ichudov@gmail.com
Subject: Re: Postgres for a "data warehouse", 5-10 TB
In-Reply-To: <20110912022926.GP12765@tamriel.snowman.net>
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