Re: 7.2.1 optimises very badly against 7.2

From: Jean-Luc Lachance <jllachan(at)nsd(dot)ca>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Sam Liddicott <sam(dot)liddicott(at)ananova(dot)com>, pgsql-general(at)postgresql(dot)org
Subject: Re: 7.2.1 optimises very badly against 7.2
Date: 2002-07-12 14:45:13
Message-ID: 3D2EEB79.F20AD831@nsd.ca
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Just curious,

Is the number of record per page and the number of key per page taken in
consideration?

Tom Lane wrote:
>
> "Sam Liddicott" <sam(dot)liddicott(at)ananova(dot)com> writes:
> > Do you feel the random page cost of 3 is good to solve this?
>
> For the moment, anyway. There have been a couple of rounds of
> pgsql-hackers discussion about whether to lower the default value of
> random_page_cost, but so far no one has done any experiments that
> would be needed to establish a good new value. (The current default
> of 4.0 is based on some old experiments I did. I'm quite willing to
> accept that those experiments might have been flawed, but not willing
> to replace the number without seeing better experiments...)
>
> regards, tom lane
>
> ---------------------------(end of broadcast)---------------------------
> TIP 4: Don't 'kill -9' the postmaster

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