X-Original-To: pgsql-hackers-postgresql.org@localhost.postgresql.org Received: from localhost (unknown [200.46.204.2]) by svr1.postgresql.org (Postfix) with ESMTP id 3250BD1CCBE for ; Thu, 5 Feb 2004 21:27:23 +0000 (GMT) Received: from svr1.postgresql.org ([200.46.204.71]) by localhost (neptune.hub.org [200.46.204.2]) (amavisd-new, port 10024) with ESMTP id 97562-07 for ; Thu, 5 Feb 2004 17:27:20 -0400 (AST) Received: from tht.net (vista.tht.net [216.126.88.2]) by svr1.postgresql.org (Postfix) with ESMTP id 7E87ED1B8A3 for ; Thu, 5 Feb 2004 17:27:02 -0400 (AST) Received: from [134.22.70.253] (dyn-70-253.tor.dsl.tht.net [134.22.70.253]) by tht.net (Postfix) with ESMTP id EE8B476A4D; Thu, 5 Feb 2004 16:26:21 -0500 (EST) Subject: Re: Preventing duplicate vacuums? From: Rod Taylor To: Josh Berkus Cc: PostgreSQL Development In-Reply-To: <200402051237.14615.josh@agliodbs.com> References: <200402051237.14615.josh@agliodbs.com> Content-Type: text/plain Message-Id: <1076016392.308.539.camel@jester> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.5 Date: Thu, 05 Feb 2004 16:26:33 -0500 Content-Transfer-Encoding: 7bit X-Virus-Scanned: by amavisd-new at postgresql.org X-Archive-Number: 200402/211 X-Sequence-Number: 49800 On Thu, 2004-02-05 at 15:37, Josh Berkus wrote: > Folks, > > Just occurred to me that we have no code to prevent a user from running two > simultaneos lazy vacuums on the same table. I can't think of any > circumstance why running two vacuums would be desirable behavior; how > difficult would it be to make this an exception? You have a 8 billion row table with some very high turn over tuples (lots of updates to a few thousand rows). A partial or targeted vacuum would be best, failing that you kick them off fairly frequently, especially if IO isn't really an issue.