Received: from localhost (maia-2.hub.org [200.46.204.187]) by postgresql.org (Postfix) with ESMTP id 698169FB6C1 for ; Wed, 28 Feb 2007 01:34:58 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.187]) (amavisd-new, port 10024) with ESMTP id 71193-06 for ; Wed, 28 Feb 2007 01:34:55 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey-1.7.4 Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id 8DF6A9FB2DC for ; Wed, 28 Feb 2007 01:34:55 -0400 (AST) 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 l1S5Yp4q025503; Wed, 28 Feb 2007 00:34:51 -0500 (EST) To: Heikki Linnakangas cc: "Jim C. Nasby" , ITAGAKI Takahiro , pgsql-hackers@postgresql.org Subject: Re: Dead Space Map version 2 In-reply-to: <45E3FF0D.2050104@enterprisedb.com> References: <20070227113655.6381.ITAGAKI.TAKAHIRO@oss.ntt.co.jp> <20070227051144.GK29041@nasby.net> <12631.1172555721@sss.pgh.pa.us> <45E3FF0D.2050104@enterprisedb.com> Comments: In-reply-to Heikki Linnakangas message dated "Tue, 27 Feb 2007 09:51:09 +0000" Date: Wed, 28 Feb 2007 00:34:51 -0500 Message-ID: <25502.1172640891@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200702/1798 X-Sequence-Number: 99351 Heikki Linnakangas writes: > Tom Lane wrote: >> I'd be happier if the DSM content could be >> treated as just a hint. > If we don't have a frozen state, we can't use the DSM to implement > index-only scans. To implement index-only scans, the DSM would have to be expected to provide 100% reliable coverage, which will increase its cost and complexity by orders of magnitude. If you insist on that, I will bet you lunch at a fine restaurant that it doesn't make it into 8.3. regards, tom lane