Received: from localhost (unknown [200.46.204.183]) by postgresql.org (Postfix) with ESMTP id 023D437BFDB for ; Mon, 29 Sep 2008 20:44:31 -0300 (ADT) Received: from postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 82105-01 for ; Mon, 29 Sep 2008 20:44:28 -0300 (ADT) 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 postgresql.org (Postfix) with ESMTP id 4910637BF7A for ; Mon, 29 Sep 2008 20:44:28 -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 m8TNiOYM026114; Mon, 29 Sep 2008 19:44:24 -0400 (EDT) To: Steve Crawford cc: Scott Marlowe , Peter Kovacs , pgsql-admin@postgresql.org Subject: Re: Do we need vacuuming when tables are regularly dropped? In-reply-to: <48E1606E.7070702@pinpointresearch.com> References: <9815.1222690583@sss.pgh.pa.us> <48E10C95.2050207@pinpointresearch.com> <25195.1222728353@sss.pgh.pa.us> <48E1606E.7070702@pinpointresearch.com> Comments: In-reply-to Steve Crawford message dated "Mon, 29 Sep 2008 16:10:38 -0700" Date: Mon, 29 Sep 2008 19:44:24 -0400 Message-ID: <26113.1222731864@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0 tagged_above=0 required=5 tests=none X-Spam-Level: X-Archive-Number: 200809/347 X-Sequence-Number: 30440 Steve Crawford writes: > postgres@[local]=> CLUSTER pg_class USING pg_class_oid_index ; > ERROR: "pg_class" is a system catalog I think the DB is probably protecting you from yourself here ;-). If memory serves there are some system indexes whose relfilenode numbers can't change, and pg_class_oid_index is one of them. If the CLUSTER had gone through you'd have hosed that database irretrievably. The protection check that is firing here is not so fine-grained as to know the difference between pg_class and catalogs that this might be safe for; but it does point up the moral that you need to know exactly what you're doing if you are going to do DDL stuff on the system catalogs. regards, tom lane