Re: 7.3 LOCK TABLE problem

From: Neil Conway <neilc(at)samurai(dot)com>
To: cgg007(at)yahoo(dot)com
Cc: PostgreSQL General <pgsql-general(at)postgresql(dot)org>
Subject: Re: 7.3 LOCK TABLE problem
Date: 2003-01-27 20:36:55
Message-ID: 1043699815.32114.182.camel@tokyo
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On Mon, 2003-01-27 at 15:21, Chris Gamache wrote:
> BEGIN;
> LOCK TABLE queue IN EXCLUSIVE MODE;
> UPDATE queue
> set status=$$
> WHERE id = (SELECT min(id)
> FROM queue
> WHERE status=0);

This is unrelated, but note that the sub-select would probably be faster
written as:

SELECT id FROM queue WHERE status = 0 ORDER BY id ASC LIMIT 1;

As this form of the query can use a btree index on "id" if one's
present.

> SELECT id, data
> FROM queue
> WHERE status=$procid;

My Perl's a bit rusty, but AFAICS $procid is undefined. Perhaps 'perl
-w' and "use strict;" would be a good idea?

Cheers,

Neil

--
Neil Conway <neilc(at)samurai(dot)com> || PGP Key ID: DB3C29FC

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