Received: from localhost (maia-5.hub.org [200.46.204.182]) by postgresql.org (Postfix) with ESMTP id B55B19FB538 for ; Thu, 28 Jun 2007 13:08:46 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.182]) (amavisd-maia, port 10024) with ESMTP id 54900-01 for ; Thu, 28 Jun 2007 13:08:38 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id E2E979FB540 for ; Thu, 28 Jun 2007 13:08:38 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.1/8.14.1) with ESMTP id l5SG8bgV013617; Thu, 28 Jun 2007 12:08:37 -0400 (EDT) To: "Dolafi, Tom" cc: pgsql-performance@postgresql.org Subject: Re: rtree/gist index taking enormous amount of space in 8.2.3 In-reply-to: References: Comments: In-reply-to "Dolafi, Tom" message dated "Wed, 27 Jun 2007 11:17:48 -0400" Date: Thu, 28 Jun 2007 12:08:37 -0400 Message-ID: <13616.1183046917@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200706/636 X-Sequence-Number: 25669 "Dolafi, Tom" writes: > In version 8.1.5, I have an rtree index on a 1.5 GB table. The size of > this index is 500 MB. After migrating to 8.2.3, the size of this index > has increased to 35GB. I've dropped are recreated the index and got the > same result. In 8.2.3 the index type is gist, does this have something > to do with it? We dropped rtree in 8.2 on the strength of experiments that seemed to show gist was always better, but you seem to have an outlier case... Can you tell us something about the distribution of the data values (fmin and fmax)? Is there anything particularly magic about the two constants you're using in the boxes? I suppose you've hit some bad corner case in the gist box opclass, but it's not clear what. regards, tom lane