Received: from localhost (unknown [200.46.204.184]) by postgresql.org (Postfix) with ESMTP id 844B19FCB8C for ; Fri, 9 Nov 2007 03:10:13 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.184]) (amavisd-maia, port 10024) with ESMTP id 78467-02-9 for ; Fri, 9 Nov 2007 03:10:00 -0400 (AST) Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id 9B80A9FCBAE for ; Fri, 9 Nov 2007 03:08:59 -0400 (AST) 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 lA978uWJ001690; Fri, 9 Nov 2007 02:08:56 -0500 (EST) To: "Chris Hoover" cc: "PGSQL Performance" Subject: Re: Help understanding stat numbers In-reply-to: <1d219a6f0711080649w22a1eec6j69cab5ea5e5bc74b@mail.gmail.com> References: <1d219a6f0711080649w22a1eec6j69cab5ea5e5bc74b@mail.gmail.com> Comments: In-reply-to "Chris Hoover" message dated "Thu, 08 Nov 2007 09:49:41 -0500" Date: Fri, 09 Nov 2007 02:08:56 -0500 Message-ID: <1689.1194592136@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200711/129 X-Sequence-Number: 27544 "Chris Hoover" writes: > If there has been no scans on an index (as according to > pg_stat_user_indexes), why is pg_statio_user_indexes showing non 0 > values in idx_blks_hit/read? I grow weary, but I think that "scan" is only incremented by commencing a SELECT search using the index, whereas the block-level counts are also incremented when the index is modified by an insert or update. You may be looking at indexes that are eating update cycles but not being used for anything important... regards, tom lane