Received: from maia.hub.org (maia-5.hub.org [200.46.204.29]) by mail.postgresql.org (Postfix) with ESMTP id 62AE31337B4B for ; Thu, 30 Sep 2010 12:57:48 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.29]) (amavisd-maia, port 10024) with ESMTP id 93101-07 for ; Thu, 30 Sep 2010 15:57:41 +0000 (UTC) X-Greylist: delayed 00:07:08.511989 by SQLgrey-1.7.6 Received: from mail-iw0-f174.google.com (mail-iw0-f174.google.com [209.85.214.174]) by mail.postgresql.org (Postfix) with ESMTP id 9FF0B1337B68 for ; Thu, 30 Sep 2010 12:57:40 -0300 (ADT) Received: by iwn5 with SMTP id 5so2595859iwn.19 for ; Thu, 30 Sep 2010 08:57:40 -0700 (PDT) Received: by 10.231.15.76 with SMTP id j12mr3968359iba.30.1285861830537; Thu, 30 Sep 2010 08:50:30 -0700 (PDT) MIME-Version: 1.0 Received: by 10.231.199.4 with HTTP; Thu, 30 Sep 2010 08:50:10 -0700 (PDT) From: Terry Schmitt Date: Thu, 30 Sep 2010 08:50:10 -0700 Message-ID: Subject: pg_dumpall blocking other sessions To: pgsql-admin@postgresql.org Content-Type: text/plain; charset=ISO-8859-1 X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-1.9 tagged_above=-10 required=5 tests=BAYES_00=-1.9, RCVD_IN_DNSWL_NONE=-0.0001 X-Spam-Level: X-Archive-Number: 201009/195 X-Sequence-Number: 35739 Hi All, I had a situation where a session was getting blocked while per performing a pg_dumpall. I could see the pg_dumpall session executing a COPY command on a table in one schema. Another user session was attempting to truncate a different table in a different schema, but in the same database. This session was being blocked by the pg_dumpall session. I intend to test this further, but my understanding was that pg_dump was a non-blocking operation. I'm still on the learning curve with Postgres 8.4 (actually EnterpriseDB Advanced Server), so maybe I just need more detail on how pg_dumpall works. Is the truncate perhaps the problem, but other dml is allowed? Thanks much, Terry