From: Joost Kraaijeveld <J.Kraaijeveld@Askesis.nl>
To: Tino Wildenhain <tino@wildenhain.de>
Cc: Csaba Nagy <nagy@ecircle-ag.com>
Cc: Pgsql-Performance <pgsql-performance@postgresql.org>
Subject: Re: Can this query go faster???
Date: Tue, 06 Dec 2005 13:20:45 +0100
Message-ID: <1133871645.8837.78.camel@Panoramix> (raw)
In-Reply-To: <439577D2.9090208@wildenhain.de>
References: <1133862229.8837.61.camel@Panoramix>
<1133862777.4779.185.camel@coppola.muc.ecircle.de>
<1133864460.8837.69.camel@Panoramix>
<439568C4.8050601@wildenhain.de>
<1133868084.8837.73.camel@Panoramix>
<439577D2.9090208@wildenhain.de>
On Tue, 2005-12-06 at 12:36 +0100, Tino Wildenhain wrote:
> >
> > I just tried it: a cursor is not faster (what does not surprise me at
> > all, as the amount of work looks the same to me)
>
> Actually no, if you scroll forward, you just ask the database for the
> next rows to materialize. So if you are ahead in your database and
> ask for next rows, it should be faster then working w/ an offset
> from start each time.
Ah, a misunderstanding: I only need to calculate an index if the user
wants a record that is not in or adjacent to the cache (in which case I
can do a "select values > last value in the cache". So I must always
materialize all rows below the wanted index.
--
Groeten,
Joost Kraaijeveld
Askesis B.V.
Molukkenstraat 14
6524NB Nijmegen
tel: 024-3888063 / 06-51855277
fax: 024-3608416
e-mail: J.Kraaijeveld@Askesis.nl
web: www.askesis.nl
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To: pgsql-performance@postgresql.org
Cc: J.Kraaijeveld@Askesis.nl, tino@wildenhain.de, nagy@ecircle-ag.com
Subject: Re: Can this query go faster???
In-Reply-To: <1133871645.8837.78.camel@Panoramix>
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