X-Original-To: pgsql-sql-postgresql.org@localhost.postgresql.org Received: from localhost (unknown [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id 22CE6329D04 for ; Wed, 8 Sep 2004 22:12:07 +0100 (BST) Received: from svr1.postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 39039-07 for ; Wed, 8 Sep 2004 21:11:56 +0000 (GMT) Received: from fedk0913.Ferring.com (unknown [213.237.141.22]) by svr1.postgresql.org (Postfix) with ESMTP id 003CF329CF8 for ; Wed, 8 Sep 2004 22:11:56 +0100 (BST) Received: from fedk0005.Fic.ferring.com (unverified [206.182.35.205]) by fedk0913.Ferring.com (Content Technologies SMTPRS 4.3.12) with ESMTP id for ; Wed, 8 Sep 2004 23:12:08 +0200 Received: from [10.20.100.63] (10.20.100.63 [10.20.100.63]) by fedk0005.Fic.ferring.com with SMTP (Microsoft Exchange Internet Mail Service Version 5.5.2653.13) id SMFD00L4; Wed, 8 Sep 2004 23:11:51 +0200 Message-ID: <413F758A.80306@ferring.com> Date: Wed, 08 Sep 2004 14:11:38 -0700 From: Kemin Zhou User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.2) Gecko/20040803 X-Accept-Language: en-us, en MIME-Version: 1.0 To: pgsql-sql@postgresql.org Subject: aggregate function stddev Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0.0 tagged_above=0.0 required=5.0 tests= X-Spam-Level: X-Archive-Number: 200409/51 X-Sequence-Number: 18897 Implementers: Just noticed that the postgres stddev is the stddev_sample formula. There are two different ways to calculate this value. Their difference is very small with large samle size. It would be nice to distinguish the two different versions. I also noticed that oracle has stddev_sample and stddev_population. This is just a wish list. Kemin ********************************************************************** Proprietary or confidential information belonging to Ferring Holding SA or to one of its affiliated companies may be contained in the message. If you are not the addressee indicated in this message (or responsible for the delivery of the message to such person), please do not copy or deliver this message to anyone. In such case, please destroy this message and notify the sender by reply e-mail. Please advise the sender immediately if you or your employer do not consent to e-mail for messages of this kind. Opinions, conclusions and other information in this message represent the opinion of the sender and do not necessarily represent or reflect the views and opinions of Ferring. **********************************************************************