X-Original-To: pgsql-sql-postgresql.org@postgresql.org Received: from localhost (mx1.hub.org [200.46.208.251]) by postgresql.org (Postfix) with ESMTP id 722199FA5D2 for ; Thu, 15 Jun 2006 19:34:25 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.208.251]) (amavisd-new, port 10024) with ESMTP id 61505-05 for ; Thu, 15 Jun 2006 19:34:24 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey- Received: from grzm.com (grzm.com [200.46.204.98]) by postgresql.org (Postfix) with ESMTP id 186F39FA160 for ; Thu, 15 Jun 2006 19:34:25 -0300 (ADT) Received: from localhost (unknown [200.46.208.251]) by grzm.com (Postfix) with ESMTP id BC35F127C505 for ; Thu, 15 Jun 2006 23:34:20 +0100 (BST) Received: from grzm.com ([200.46.204.98]) by localhost (mx1.hub.org [200.46.208.251]) (amavisd-new, port 10024) with ESMTP id 60870-06; Thu, 15 Jun 2006 19:34:16 -0300 (ADT) Received: from [172.16.1.204] (unknown [61.197.227.146]) by grzm.com (Postfix) with ESMTP id 7FA6E127C4F4; Thu, 15 Jun 2006 23:34:11 +0100 (BST) In-Reply-To: <20060615221553.74364.qmail@web33302.mail.mud.yahoo.com> References: <20060615221553.74364.qmail@web33302.mail.mud.yahoo.com> Mime-Version: 1.0 (Apple Message framework v750) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: Cc: "pgsql-sql@postgresql.org" Content-Transfer-Encoding: 7bit From: Michael Glaesemann Subject: Re: SQL Technique Question Date: Fri, 16 Jun 2006 07:34:11 +0900 To: X-Mailer: Apple Mail (2.750) X-Virus-Scanned: Maia Mailguard 1.0.1 X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200606/190 X-Sequence-Number: 25426 [Please quote responsibly. There was no need to quote my entire message back to the list.] On Jun 16, 2006, at 7:15 , wrote: > i need to become mor familiar with views. if i use > views, will i substantially impair performance? Short answer: maybe, maybe not Long answer: benchmark and compare. EXPLAIN ANALYZE is your friend. For example, compare the EXPLAIN ANALYZE output using the view and using the whole, explicit query. You'll learn a lot that will only help you write better queries. Michael Glaesemann grzm seespotcode net