X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by postgresql.org (Postfix) with ESMTP id 1A9469DD5F0 for ; Tue, 6 Dec 2005 17:20:59 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 95523-03 for ; Tue, 6 Dec 2005 17:21:00 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey- Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id A6C409DD5F5 for ; Tue, 6 Dec 2005 17:20:56 -0400 (AST) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.1/8.13.1) with ESMTP id jB6LKvsS016452; Tue, 6 Dec 2005 16:20:57 -0500 (EST) To: stange@rentec.com cc: Vivek Khera , Postgresql Performance Subject: Re: postgresql performance tuning In-reply-to: <4395F914.8070001@rentec.com> References: <4395F914.8070001@rentec.com> Comments: In-reply-to Alan Stange message dated "Tue, 06 Dec 2005 15:48:20 -0500" Date: Tue, 06 Dec 2005 16:20:57 -0500 Message-ID: <16451.1133904057@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=0.002 required=5 tests=[AWL=0.002] X-Spam-Score: 0.002 X-Spam-Level: X-Archive-Number: 200512/195 X-Sequence-Number: 16016 Alan Stange writes: > Vivek Khera wrote: >> what evidence do you have that you are suffering index bloat? > The files for the two indices on a single table used 7.8GB of space > before a reindex, and 4.4GB after. That's not bloat ... that's pretty nearly in line with the normal expectation for a btree index, which is about 2/3rds fill factor. If the compacted index were 10X smaller then I'd agree that you have a bloat problem. Periodic reindexing on this scale is not doing a lot for you except thrashing your disks --- you're just giving space back to the OS that will shortly be sucked up again by the same index. regards, tom lane