X-Original-To: pgsql-performance-postgresql.org@postgresql.org Received: from localhost (wm.hub.org [200.46.204.128]) by postgresql.org (Postfix) with ESMTP id 6CF929FB505 for ; Sat, 2 Sep 2006 11:21:28 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.128]) (amavisd-new, port 10024) with ESMTP id 35014-07 for ; Sat, 2 Sep 2006 14:21:25 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey- Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id 5BE629FB503 for ; Sat, 2 Sep 2006 11:21:24 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.6/8.13.6) with ESMTP id k82ELNo7002192; Sat, 2 Sep 2006 10:21:23 -0400 (EDT) To: Matteo Sgalaberni cc: pgsql-performance@postgresql.org Subject: Re: database bloat, non removovable rows, slow query etc... [RESOLVED] In-reply-to: <20060902083725.GB2266@sgala.com> References: <20060901123915.GT2266@sgala.com> <4027.1157121810@sss.pgh.pa.us> <20060901172829.GX2266@sgala.com> <12756.1157132120@sss.pgh.pa.us> <20060902083725.GB2266@sgala.com> Comments: In-reply-to Matteo Sgalaberni message dated "Sat, 02 Sep 2006 10:37:25 +0200" Date: Sat, 02 Sep 2006 10:21:23 -0400 Message-ID: <2191.1157206883@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200609/15 X-Sequence-Number: 20701 Matteo Sgalaberni writes: > Good to know this...but why this behaviour? it'is lovely...:) Open transactions are tracked across the whole cluster. This is necessary when vacuuming shared catalogs. In principle we could track per-database xmin values as well, but the distributed overhead that'd be added to *every* GetSnapshotData call is a bit worrisome. regards, tom lane