X-Original-To: pgsql-performance@postgresql.org Received: from localhost (postgresql.org [64.49.215.8]) by postgresql.org (Postfix) with ESMTP id 1221C475A97 for ; Tue, 25 Feb 2003 11:19:17 -0500 (EST) Received: from postgresql.org ([64.49.215.8]) by localhost (postgresql.org [64.49.215.8:10024]) (amavisd-new) with SMTP id 55884-01 for ; Tue, 25 Feb 2003 11:19:06 -0500 (EST) Received: from sss.pgh.pa.us (unknown [192.204.191.242]) by postgresql.org (Postfix) with ESMTP id 7CB87475AFA for ; Tue, 25 Feb 2003 11:07:11 -0500 (EST) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.12.6/8.12.6) with ESMTP id h1PG7F5u010855; Tue, 25 Feb 2003 11:07:16 -0500 (EST) To: Robert Treat Cc: Josh Berkus , Clarence Gardner , Oleg Lebedev , "pgsql-performance@postgresql.org" Subject: Re: slow query In-reply-to: <1046186882.1015.377.camel@camel> References: <1046111434.1014.165.camel@camel> <200302241045.20856.josh@agliodbs.com> <5421.1046119835@sss.pgh.pa.us> <1046186882.1015.377.camel@camel> Comments: In-reply-to Robert Treat message dated "25 Feb 2003 10:28:02 -0500" Date: Tue, 25 Feb 2003 11:07:15 -0500 Message-ID: <10854.1046189235@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: by amavisd-new X-Archive-Number: 200302/200 X-Sequence-Number: 1256 Robert Treat writes: > Would it be safe to say that tables with high update rates where the > updates do not change the indexed value would not suffer from index > bloat? I would expect not. If you vacuum often enough to keep the main table size under control, the index should stay under control too. > For example updates to non-index columns or updates that > overwrite, but don't change the value of indexed columns; do these even > need to touch the index? Yes, they do. Think MVCC. regards, tom lane