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Re: Group-count estimation statistics

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Manfred Koizar <mkoi-pg(at)aon(dot)at>
Cc: pgsql-hackers(at)postgresql(dot)org
Subject: Re: Group-count estimation statistics
Date: 2005-01-31 19:40:08
Message-ID: 22119.1107200408@sss.pgh.pa.us (view raw or flat)
Thread:
Lists: pgsql-hackers
Manfred Koizar <mkoi-pg(at)aon(dot)at> writes:
> That's not what I meant.  I tried to say that if we have a GROUP BY
> several columns and one of these columns alone has more than N/10
> distinct values, there's no way to get less than that many groups.

Oh, I see, you want a "max" calculation in there too.  Seems reasonable.
Any objections?

			regards, tom lane

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