From: Josh Berkus <josh@agliodbs.com>
To: pgsql-performance@postgresql.org
Subject: Re: Query using SeqScan instead of IndexScan
Date: Sun, 2 Apr 2006 15:30:55 -0700
Message-ID: <200604021530.55251.josh@agliodbs.com> (raw)
In-Reply-To: <DFA31453-E99A-4BB9-80C7-520E0C72CAFA@clickspace.com>
References: <2F1712F1-E5E2-455E-A291-06F300A66549@clickspace.com>
<200603292118.50033.josh@agliodbs.com>
<DFA31453-E99A-4BB9-80C7-520E0C72CAFA@clickspace.com>
Brendan,
> But just as a follow up question to your #1 suggestion, I have 8 GB
> of ram in my production server. You're saying to set the
> effective_cache_size then to 5 GB roughly? Somewhere around 655360?
> Currently it is set to 65535. Is that something that's OS dependent?
> I'm not sure how much memory my server sets aside for disk caching.
Yes, about. It's really a judgement call; you're looking for the approximate
combined RAM available for disk caching and shared mem. However, this is
just used as a way of estimating the probability that the data you want is
cached in memory, so you're just trying to be order-of-magnitude accurate,
not to-the-MB accurate.
--
Josh Berkus
Aglio Database Solutions
San Francisco
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To: pgsql-performance@postgresql.org
Cc: josh@agliodbs.com
Subject: Re: Query using SeqScan instead of IndexScan
In-Reply-To: <200604021530.55251.josh@agliodbs.com>
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