X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by postgresql.org (Postfix) with ESMTP id 9BBD89DCD3B for ; Sat, 10 Dec 2005 12:53:53 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 88981-09 for ; Sat, 10 Dec 2005 12:53:52 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey- Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id 58A219DCBEE for ; Sat, 10 Dec 2005 12:53:51 -0400 (AST) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.1/8.13.1) with ESMTP id jBAGroRM021006; Sat, 10 Dec 2005 11:53:50 -0500 (EST) To: Henrique Engelmann cc: pgsql-performance@postgresql.org Subject: Re: Clustered tables and seqscan disabled In-reply-to: <20051210152937.71243.qmail@web36410.mail.mud.yahoo.com> References: <20051210152937.71243.qmail@web36410.mail.mud.yahoo.com> Comments: In-reply-to Henrique Engelmann message dated "Sat, 10 Dec 2005 15:29:37 +0000" Date: Sat, 10 Dec 2005 11:53:50 -0500 Message-ID: <21005.1134233630@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=0.003 required=5 tests=[AWL=0.003] X-Spam-Score: 0.003 X-Spam-Level: X-Archive-Number: 200512/272 X-Sequence-Number: 16093 Henrique Engelmann writes: > I suggested changing the application and including a order by clause... but > the software house didnīt make it because they said the system was originally designed for oracle and they did not need to use the ORDER BY clause with Oracle and even so the data were always retrieved in primary index order. > Iīm thinking with myself ... what kind of problems will they have in the future? If you aren't working with these people any more, be glad. They are obviously utterly incompetent. The SQL standard is perfectly clear about the matter: without ORDER BY, there is no guarantee about the order in which rows are retrieved. The fact that one specific implementation might have chanced to produce the rows in desired order (under all the conditions they had bothered to test, which I bet wasn't a lot) does not make their code correct. regards, tom lane