X-Original-To: pgsql-sql-postgresql.org@localhost.postgresql.org Received: from localhost (unknown [200.46.204.2]) by svr1.postgresql.org (Postfix) with ESMTP id 998A0D1E434 for ; Thu, 18 Mar 2004 06:36:44 +0000 (GMT) Received: from svr1.postgresql.org ([200.46.204.71]) by localhost (neptune.hub.org [200.46.204.2]) (amavisd-new, port 10024) with ESMTP id 16071-10 for ; Thu, 18 Mar 2004 02:36:34 -0400 (AST) Received: from rock.spider.ru (rock.spider.ru [62.183.34.226]) by svr1.postgresql.org (Postfix) with ESMTP id 5F4AAD1DB59 for ; Thu, 18 Mar 2004 02:36:33 -0400 (AST) Received: from rock (localhost [127.0.0.1]) by rock (Postfix) with SMTP id 127CF913D3 for ; Thu, 18 Mar 2004 09:36:33 +0300 (MSK) Received: from sad.localnet.ru (sad.localnet.ru [10.0.0.33]) by rock.spider.ru (Postfix) with ESMTP id AB3A8913D0 for ; Thu, 18 Mar 2004 09:36:32 +0300 (MSK) Content-Type: text/plain; charset="us-ascii" From: sad Organization: IT To: pgsql-sql@postgresql.org Subject: perfomance question Date: Thu, 18 Mar 2004 09:41:45 +0300 User-Agent: KMail/1.4.3 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Message-Id: <200403180941.45591.sad@bankir.ru> X-Virus-Scanned: by amavisd-new at postgresql.org X-Archive-Number: 200403/193 X-Sequence-Number: 17292 hello. what are perfomance difference bitween a) update t1 set f1 =3D 'x', f2 =3D 'y'; b) update t1 set f1 =3D 'x', f2 =3D f2; c) update t1 set f1 =3D 'x'; ?