From: Tobias Brox <tobias@nordicbet.com>
To: Kjell Tore Fossbakk <kjelltore@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Querying 19million records very slowly
Date: Wed, 22 Jun 2005 16:03:57 +0800
Message-ID: <20050622080357.GW7839@tobias> (raw)
In-Reply-To: <e79986c505062200457fe97695@mail.gmail.com>
References: <e79986c505062112094f579a9b@mail.gmail.com>
<42B8719A.6040809@refractions.net>
<op.ssqot4d4th1vuj@localhost>
<e79986c505062200457fe97695@mail.gmail.com>
[Kjell Tore Fossbakk - Wed at 09:45:22AM +0200]
> database=> explain analyze select count(*) from test where p1=53 and
> time > now() - interval '24 hours' ;
Sorry to say that I have not followed the entire thread neither read the
entire email I'm replying to, but I have a quick hint on this one (ref my
earlier thread about timestamp indices) - the postgresql planner will
generally behave smarter when using a fixed timestamp (typically generated
by the app server) than logics based on now().
One of my colleagues also claimed that he found the usage of
localtimestamp faster than now().
--
Tobias Brox, +86-13521622905
Nordicbet, IT dept
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To: pgsql-performance@postgresql.org
Cc: tobias@nordicbet.com, kjelltore@gmail.com
Subject: Re: Querying 19million records very slowly
In-Reply-To: <20050622080357.GW7839@tobias>
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