Received: from makus.postgresql.org (makus.postgresql.org [98.129.198.125]) by mail.postgresql.org (Postfix) with ESMTP id 63D2823D696 for ; Mon, 23 Jul 2012 12:09:43 -0300 (ADT) Received: from sss.pgh.pa.us ([66.207.139.130]) by makus.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1StKGU-0004OH-2k for pgsql-performance@postgresql.org; Mon, 23 Jul 2012 15:09:42 +0000 Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.5/8.14.5) with ESMTP id q6NF9GiH029949; Mon, 23 Jul 2012 11:09:17 -0400 (EDT) From: Tom Lane To: Jim Vanns cc: pgsql-performance@postgresql.org Subject: Re: Odd blocking (or massively latent) issue - even with EXPLAIN In-reply-to: <1343032905.12579.3.camel@sys367.ldn.framestore.com> References: <1343032905.12579.3.camel@sys367.ldn.framestore.com> Comments: In-reply-to Jim Vanns message dated "Mon, 23 Jul 2012 09:41:45 +0100" Date: Mon, 23 Jul 2012 11:09:16 -0400 Message-ID: <29948.1343056156@sss.pgh.pa.us> X-Pg-Spam-Score: -1.9 (-) X-Archive-Number: 201207/271 X-Sequence-Number: 47452 Jim Vanns writes: > We're seeing SELECT statements and even EXPLAIN (no ANAYLZE) > statements hang indefinitely until *something* (we don't know what) > releases some kind of resource or no longer becomes a massive bottle > neck. These are the symptoms. Does anything show up as blocked in the pg_locks view? Could you attach to the stuck process with gdb and get a stack trace? regards, tom lane