Received: from localhost (maia-3.hub.org [200.46.204.184]) by postgresql.org (Postfix) with ESMTP id 3AD629FA304 for ; Wed, 6 Dec 2006 03:11:51 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.184]) (amavisd-new, port 10024) with ESMTP id 03619-07 for ; Wed, 6 Dec 2006 03:11:44 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey-1.7.4 Received: from bugaboo.mu (ns1.bugaboo.mu [213.133.111.57]) by postgresql.org (Postfix) with ESMTP id 4F3539F938C for ; Wed, 6 Dec 2006 03:11:46 -0400 (AST) Received: from [192.168.77.20] (p54BD9676.dip0.t-ipconnect.de [::ffff:84.189.150.118]) (AUTH: CRAM-MD5 markus@bluegap.ch) by bugaboo.mu with esmtp; Wed, 06 Dec 2006 08:11:44 +0100 id 008F63C5.45766D31.00006FD3 Message-ID: <45766D30.3010008@bluegap.ch> Date: Wed, 06 Dec 2006 08:11:44 +0100 From: Markus Schiltknecht User-Agent: Icedove 1.5.0.8 (X11/20061128) MIME-Version: 1.0 To: Joost Kraaijeveld CC: pgsql-general@postgresql.org Subject: Re: Locking in PostgreSQL? References: <1165388652.6396.1.camel@panoramix> In-Reply-To: <1165388652.6396.1.camel@panoramix> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200612/245 X-Sequence-Number: 105184 Hi, Joost Kraaijeveld wrote: > Does PostgreSQL lock the entire row in a table if I update only 1 > column? Yes. In PostgreSQL, an update is much like a delete + insert. A concurrent transaction will still see the old row. Thus the lock only prevents other writing transactions, not readers. Regards Markus P.S.: please do not cross post such questions.