X-Original-To: pgsql-sql-postgresql.org@localhost.postgresql.org
Received: from localhost (developer.postgresql.org [64.117.224.193])
	by svr1.postgresql.org (Postfix) with ESMTP id CFB89B430A8
	for <pgsql-sql-postgresql.org@localhost.postgresql.org>;
	Mon,  7 Jul 2003 22:35:20 +0000 (GMT)
Received: from svr1.postgresql.org ([64.117.224.193])
	by localhost (svr1.postgresql.org [64.117.224.193]) (amavisd-new,
	port 10024) with ESMTP id 55629-07
	for <pgsql-sql-postgresql.org@localhost.postgresql.org>;
	Mon,  7 Jul 2003 19:35:10 -0300 (ADT)
Received: from saphir (dsl-082-082-094-159.arcor-ip.net [82.82.94.159])
	by svr1.postgresql.org (Postfix) with ESMTP id C301DB430D7
	for <pgsql-sql@postgresql.org>; Mon,  7 Jul 2003 19:35:09 -0300 (ADT)
Received: by saphir (Postfix, from userid 1000)
	id 947A41310A1; Tue,  8 Jul 2003 00:35:07 +0200 (CEST)
Subject: avoid select expens_expr(col) like unneccessary calculations
From: Markus Bertheau <twanger@bluetwanger.de>
To: pgsql-sql@postgresql.org
Content-Type: text/plain
Content-Transfer-Encoding: 7bit
Message-Id: <1057617306.2617.6.camel@saphir>
Mime-Version: 1.0
X-Mailer: Ximian Evolution 1.4.0 
Date: 08 Jul 2003 00:35:07 +0200
X-Virus-Scanned: by amavisd-new at postgresql.org
X-Archive-Number: 200307/80
X-Sequence-Number: 14194

Hi,

when you have
select expensive_expression(column), * from table offset 20 limit 40

can you somehow save the cost for the first 20 calculations of
expensive_expression?

-- 
Markus Bertheau.
Berlin, Berlin.
Germany.