X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by postgresql.org (Postfix) with ESMTP id 41A419DC84A for ; Fri, 6 Jan 2006 16:27:49 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 92396-10 for ; Fri, 6 Jan 2006 16:27:49 -0400 (AST) 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 DFEB69DC816 for ; Fri, 6 Jan 2006 16:27:46 -0400 (AST) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.1/8.13.1) with ESMTP id k06KRkXk022490; Fri, 6 Jan 2006 15:27:46 -0500 (EST) To: Ian Westmacott cc: "Jim C. Nasby" , pgsql-performance@postgresql.org Subject: Re: improving write performance for logging In-reply-to: <1136574178.31602.13.camel@spectre.intellivid.com> References: <43BB0C5C.8020207@computer.org> <1136382865.24450.7.camel@spectre.intellivid.com> <7.0.1.0.2.20060104092139.01c37da0@earthlink.net> <1136390438.24450.49.camel@spectre.intellivid.com> <20060106010822.GK43311@pervasive.com> <1136556006.31602.5.camel@spectre.intellivid.com> <20060106163732.GL3902@pervasive.com> <1136574178.31602.13.camel@spectre.intellivid.com> Comments: In-reply-to Ian Westmacott message dated "Fri, 06 Jan 2006 14:02:57 -0500" Date: Fri, 06 Jan 2006 15:27:46 -0500 Message-ID: <22489.1136579266@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=0.072 required=5 tests=[AWL=0.072] X-Spam-Score: 0.072 X-Spam-Level: X-Archive-Number: 200601/44 X-Sequence-Number: 16522 Ian Westmacott writes: > If the WAL is lost, can you lose more than the data since the last > checkpoint? The problem is that you might have partially-applied actions since the last checkpoint, rendering your database inconsistent; then *all* the data is suspect if not actually corrupt. regards, tom lane