X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (mx1.hub.org [200.46.208.251]) by postgresql.org (Postfix) with ESMTP id 7346F9FA226 for ; Wed, 3 May 2006 08:22:39 -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 35504-03 for ; Wed, 3 May 2006 08:22:33 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey- Received: from vms042pub.verizon.net (vms042pub.verizon.net [206.46.252.42]) by postgresql.org (Postfix) with ESMTP id BECC09FA08A for ; Wed, 3 May 2006 08:22:33 -0300 (ADT) Received: from osgiliath.mathom.us ([70.108.132.172]) by vms042.mailsrvcs.net (Sun Java System Messaging Server 6.2-4.02 (built Sep 9 2005)) with ESMTPA id <0IYO00FWMSXDHMU3@vms042.mailsrvcs.net> for pgsql-performance@postgresql.org; Wed, 03 May 2006 06:22:26 -0500 (CDT) Received: from localhost (localhost [127.0.0.1]) by osgiliath.mathom.us (Postfix) with ESMTP id 0F42A6E5DD for ; Wed, 03 May 2006 07:22:23 -0400 (EDT) Received: from osgiliath.mathom.us ([127.0.0.1]) by localhost (osgiliath.home.mathom.us [127.0.0.1]) (amavisd-new, port 10024) with LMTP id 13838-04 for ; Wed, 03 May 2006 07:22:22 -0400 (EDT) Received: by osgiliath.mathom.us (Postfix, from userid 1000) id EDA736ECBD; Wed, 03 May 2006 07:22:21 -0400 (EDT) Date: Wed, 03 May 2006 07:22:21 -0400 From: Michael Stone Subject: Re: Why so slow? In-reply-to: <20060502192834.6c8e9131.wmoran@collaborativefusion.com> To: pgsql-performance@postgresql.org Mail-followup-to: pgsql-performance@postgresql.org Message-id: <20060503112219.GM31328@mathom.us> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii; format=flowed Content-disposition: inline X-Pgp-Fingerprint: 53 FF 38 00 E7 DD 0A 9C 84 52 84 C5 EE DF 7C 88 X-Virus-Scanned: Debian amavisd-new at mathom.us References: <200604281043.16083@hal.medialogik.com> <20060430100346.20f010a9.wmoran@collaborativefusion.com> <20060502201740.GB97354@pervasive.com> <20060502192834.6c8e9131.wmoran@collaborativefusion.com> User-Agent: Mutt/1.5.11+cvs20060403 X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200605/79 X-Sequence-Number: 18866 On Tue, May 02, 2006 at 07:28:34PM -0400, Bill Moran wrote: >Reindexing is in a different class than vacuuming. Kinda, but it is in the same class as vacuum full. If vacuum neglect (or dramatic change in usage) has gotten you to the point of 10G of overhead on a 2G table you can get a dramatic speedup if you vacuum full, by dumping a lot of unused space. But in that case you might have a similar amount of overhead in indices, which isn't going to go away unless you reindex. In either case the unused rows will be reused as needed, but if you know you aren't going to need the space again anytime soon you might need to vacuum full/reindex. Mike Stone