Received: from localhost (maia-1.hub.org [200.46.204.191]) by postgresql.org (Postfix) with ESMTP id 67D899FB46B for ; Fri, 12 Jan 2007 14:49:10 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.191]) (amavisd-new, port 10024) with ESMTP id 47071-02 for ; Fri, 12 Jan 2007 14:48:45 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey-1.7.4 Received: from exchange.g2switchworks.com (mail.g2switchworks.com [63.87.162.25]) by postgresql.org (Postfix) with ESMTP id 11EC99FB43E for ; Fri, 12 Jan 2007 14:48:44 -0400 (AST) Received: from 10.10.1.37 ([10.10.1.37]) by exchange.g2switchworks.com ([10.10.1.2]) with Microsoft Exchange Server HTTP-DAV ; Fri, 12 Jan 2007 18:48:42 +0000 Received: from state.g2switchworks.com by mail.g2switchworks.com; 12 Jan 2007 12:48:42 -0600 Subject: Re: deleting records from a table From: Scott Marlowe To: Mario Behring Cc: pgsql-sql@postgresql.org In-Reply-To: <4186.26875.qm@web30014.mail.mud.yahoo.com> References: <4186.26875.qm@web30014.mail.mud.yahoo.com> Content-Type: text/plain Content-Transfer-Encoding: 7bit Message-Id: <1168624891.20602.693.camel@state.g2switchworks.com> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 (1.4.6-2) Date: Fri, 12 Jan 2007 12:48:42 -0600 X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200701/41 X-Sequence-Number: 27193 On Fri, 2007-01-12 at 11:45, Mario Behring wrote: > Hi all, > > Simple question: once I execute the delete statement, does it free > disk space immediatelly? Does Postgres uses something like a datafile > with a pre-defined size like Oracle does?? > Take a look here: http://www.postgresql.org/docs/8.2/static/routine-vacuuming.html http://www.postgresql.org/docs/8.2/static/mvcc-intro.html That should explain the basics of mvcc and vacuuming as applies to pgsql.