From: Michael Glaesemann <grzm@myrealbox.com>
To: jcfischer <jcfischer.lists@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: nested query on last n rows of huge table
Date: Wed, 1 Mar 2006 12:44:25 +0900
Message-ID: <DF8206DD-3B0F-41DA-BA21-4D14945EB7BF@myrealbox.com> (raw)
In-Reply-To: <1140790410.923941.261250@p10g2000cwp.googlegroups.com>
References: <1140790410.923941.261250@p10g2000cwp.googlegroups.com>
On Feb 24, 2006, at 23:13 , jcfischer wrote:
> Is there a way to limit the expensive query to only those last 1000
> (or
> whatever) results?
>
> I have tried to nest SELECTS but my SQL-fu is to limited to get
> anything through the SQL processor :-)
The basics of a subquery are:
SELECT <expensive query>
FROM (
SELECT *
FROM table
ORDER eventtime DESC
LIMIT 1000
) as most_recent_1000
Don't know enough about the other parts, but hopefully this can get
you started. :)
Michael Glaesemann
grzm myrealbox com
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To: pgsql-performance@postgresql.org
Cc: grzm@myrealbox.com, jcfischer.lists@gmail.com
Subject: Re: nested query on last n rows of huge table
In-Reply-To: <DF8206DD-3B0F-41DA-BA21-4D14945EB7BF@myrealbox.com>
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