From: Scott Marlowe <scott.marlowe@gmail.com>
To: smclellan@mintel.com
Cc: pgsql-performance@postgresql.org
Subject: Re: Query performance over a large proportion of data
Date: Tue, 10 Mar 2009 22:53:56 -0600
Message-ID: <dcc563d10903102153n588d9d90q3a86cf27f4adca54@mail.gmail.com> (raw)
In-Reply-To: <cfca83d70903102015m2c217852l2137ed78dd04f3e8@mail.gmail.com>
References: <OFBF6E3E32.2E70AF48-ON86257576.0011218D-86257576.001121A4@MintelChicago.usdmm.com>
<cfca83d70903102015m2c217852l2137ed78dd04f3e8@mail.gmail.com>
On Tue, Mar 10, 2009 at 9:15 PM, Steve McLellan <smclellan@mintel.com> wrote:
> Thanks - the nested loop is indeed causing problems - reducing
> seq_page_cost had the same effect of removing the nested loop for this
> query. We'd noticed the poor row count estimation. Increasing the statistics
> doesn't seem to have much effect, but we'll have more of a go with it.
More than likely it's the sequential page cost versus the cpu_xxx cost
setttings that's really making the difference. I.e. if you raised the
cpu_xxx settings you'd get the same result. But I'm not sure, just a
guess.
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To: pgsql-performance@postgresql.org
Cc: scott.marlowe@gmail.com, smclellan@mintel.com
Subject: Re: Query performance over a large proportion of data
In-Reply-To: <dcc563d10903102153n588d9d90q3a86cf27f4adca54@mail.gmail.com>
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