Received: from maia.hub.org (unknown [200.46.208.211]) by mail.postgresql.org (Postfix) with ESMTP id 813FB633CE9 for ; Tue, 20 Apr 2010 12:06:34 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.208.211]) (amavisd-maia, port 10024) with ESMTP id 29106-04-4 for ; Tue, 20 Apr 2010 15:06:13 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by mail.postgresql.org (Postfix) with ESMTP id 4DDF66351EF for ; Tue, 20 Apr 2010 11:58:13 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.2/8.14.2) with ESMTP id o3KEwA7H028208; Tue, 20 Apr 2010 10:58:10 -0400 (EDT) To: Scott Marlowe cc: Josh Kupershmidt , Sergey Konoplev , Steph L , pgsql-admin@postgresql.org Subject: Re: How to disconnect a single user in Postgresql 8.2.5 from a database In-reply-to: References: <480516.98593.qm@web28311.mail.ukl.yahoo.com> <15823.1271729409@sss.pgh.pa.us> <25670.1271770280@sss.pgh.pa.us> Comments: In-reply-to Scott Marlowe message dated "Tue, 20 Apr 2010 08:29:08 -0600" Date: Tue, 20 Apr 2010 10:58:10 -0400 Message-ID: <28207.1271775490@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-2.112 tagged_above=-10 required=5 tests=AWL=-0.202, BAYES_00=-1.9, T_RP_MATCHES_RCVD=-0.01 X-Spam-Level: X-Archive-Number: 201004/275 X-Sequence-Number: 34369 Scott Marlowe writes: > On Tue, Apr 20, 2010 at 7:31 AM, Tom Lane wrote: >> Scott Marlowe writes: >>> So, pg_cancel_backend(pid) is the 8.3 version, that may or may not >>> always work then, right? >> >> No, I didn't say that. > Well, my experience with it has been that it's similar and it doesn't > always work. pg_cancel_backend might or might not always succeed in canceling a query, if that's what you mean. What I'm worried about with SIGTERM'ing an individual backend is negative side-effects, like hanging the entire database. Before 8.4 there was never any attempt to ensure that that would work nicely, and if memory serves we did find some problems when we tested it. regards, tom lane