From: Steinar H. Gunderson <sgunderson@bigfoot.com>
To: pgsql-performance@postgresql.org
Subject: Re: Locking in PostgreSQL?
Date: Wed, 6 Dec 2006 14:31:04 +0100
Message-ID: <20061206133104.GA9537@uio.no> (raw)
In-Reply-To: <4ED560E4-3484-43BA-99BB-18888D968F74@fastcrypt.com>
References: <1165388652.6396.1.camel@panoramix>
<30BD1C9A-1664-4290-B343-0FB1FEBA7B53@fastcrypt.com>
<op.tj43bqe481rjf6@xjens.apus.local>
<4ED560E4-3484-43BA-99BB-18888D968F74@fastcrypt.com>
On Wed, Dec 06, 2006 at 08:26:45AM -0500, Dave Cramer wrote:
> Apparently I've completely misunderstood MVCC then.... My
> understanding is that unless you do a select ... for update then
> update the rows will not be locked .
The discussion was about updates, not selects. Selects do not in general lock
(except for ... for update, as you say).
To (partially) answer the original question: The number of columns updated
does not matter for the locking situation.
/* Steinar */
--
Homepage: http://www.sesse.net/
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To: pgsql-performance@postgresql.org
Cc: sgunderson@bigfoot.com
Subject: Re: Locking in PostgreSQL?
In-Reply-To: <20061206133104.GA9537@uio.no>
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