From: PFC <lists@boutiquenumerique.com>
To: Dawid Kuroczko <qnex42@gmail.com>
To: Postgresql Performance <pgsql-performance@postgresql.org>
Subject: Re: Planner doesn't look at LIMIT?
Date: Fri, 22 Jul 2005 15:16:57 +0200
Message-ID: <op.subgiji7th1vuj@localhost> (raw)
In-Reply-To: <758d5e7f0507220210bfa4978@mail.gmail.com>
References: <758d5e7f0507220210bfa4978@mail.gmail.com>
Which row do you want ? Do you want 'a row' at random ?
I presume you want the N latest rows ?
In that case you should use an ORDER BY on an indexed field, the serial
primary key will do nicely (ORDER BY id DESC) ; it's indexed so it will
use the index and it will fly.
> Any ideas how to make it work (other than rewriting the query to use
> subselects, use explicit id-rows, disabling hashjoin completely)?
> Or is this a bug?
>
> Regards,
> Dawid
>
> ---------------------------(end of broadcast)---------------------------
> TIP 9: In versions below 8.0, the planner will ignore your desire to
> choose an index scan if your joining column's datatypes do not
> match
>
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To: pgsql-performance@postgresql.org
Cc: lists@boutiquenumerique.com, qnex42@gmail.com
Subject: Re: Planner doesn't look at LIMIT?
In-Reply-To: <op.subgiji7th1vuj@localhost>
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