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help / color / mirror / Atom feedFrom: Greg Sabino Mullane <[email protected]>
To: [email protected]
Subject: Re: [PATCHES] Approximate count(*)
Date: Fri, 25 Mar 2005 02:34:14 -0000
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
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David Fetter wrote:
> Please find enclosed a patch that shows how to get a quick
> approximation of count(*) on a table.
You should mention that ANALYZE will also populate reltuples.
To be real anal, you should say pg_catalog.pg_class too. :)
Tom Lane asked:
>> I'm not sure we should be encouraging people to look at reltuples...
>> for one thing, it's deliberately a moving average under 8.0.
> Should there be more caveats?
Well, it already says "approximate", the value-laden word is "good".
Perhaps if that went away...
- --
Greg Sabino Mullane [email protected]
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http://biglumber.com/x/web?pk=2529DF6AB8F79407E94445B4BC9B906714964AC8
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