From owner-freebsd-hackers@FreeBSD.ORG Wed May 14 18:03:58 2008 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 7DC591065673; Wed, 14 May 2008 18:03:58 +0000 (UTC) (envelope-from hartzell@alerce.com) Received: from merlin.alerce.com (merlin.alerce.com [64.62.142.94]) by mx1.freebsd.org (Postfix) with ESMTP id 62D838FC1E; Wed, 14 May 2008 18:03:58 +0000 (UTC) (envelope-from hartzell@alerce.com) Received: from merlin.alerce.com (localhost [127.0.0.1]) by merlin.alerce.com (Postfix) with ESMTP id 13D6833C62; Wed, 14 May 2008 10:40:36 -0700 (PDT) Received: from postfix.alerce.com (w092.z064001164.sjc-ca.dsl.cnc.net [64.1.164.92]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by merlin.alerce.com (Postfix) with ESMTP id C785833C5B; Wed, 14 May 2008 10:40:35 -0700 (PDT) Received: by postfix.alerce.com (Postfix, from userid 501) id 07FCB42CABF; Wed, 14 May 2008 10:40:25 -0700 (PDT) From: George Hartzell MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <18475.9225.878567.877705@almost.alerce.com> Date: Wed, 14 May 2008 10:40:25 -0700 To: "Kurt J. Lidl" In-Reply-To: <20080514135051.GA21370@pix.net> References: <9FC19AC2-DAD8-418C-8B9C-F129DEC58CEF@gmail.com> <15336578.20080512123806@mail.ru> <200805121153.00809.jonathan+freebsd-hackers@hst.org.za> <1663320218.20080512223531@mail.ru> <20080512152430.3720683e@mbook.local> <2117635718.20080513154406@mail.ru> <20080513121452.GA70860@eos.sc1.parodius.com> <20080513154137.GA28842@pix.net> <482A02CD.7040308@mansionfamily.plus.com> <20080514135051.GA21370@pix.net> X-Mailer: VM 7.19 under Emacs 22.1.50.1 X-Virus-Scanned: ClamAV using ClamSMTP X-Mailman-Approved-At: Wed, 14 May 2008 18:22:10 +0000 Cc: Garrett Cooper , Jeremy Chadwick , Anthony Pankov , James Mansion , freebsd-hackers@freebsd.org Subject: Re: BDB corrupt X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: hartzell@alerce.com List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 14 May 2008 18:03:58 -0000 Kurt J. Lidl writes: > On Wed, May 14, 2008 at 12:25:16AM -0700, Garrett Cooper wrote: > > Most of the complaints about other DBs is licensing related, but SQLite's > > complaint was also the fact that the past stability record was a bit rocky. > > One other thing to watch for in SQLite is the lack of atomicity > in updates. It's not ACID, just like BDB 1.8x isn't ACID. > > Without a write-ahead log, you cannot be sure that the data written > actually made it to stable storage, and as such, you cannot be sure > that your database didn't get corrupted when the process stops in a > non-optimal way. In what way is SQLite not atomic? The documentation, Atomic Commit In SQLite, suggests that it is: http://www.sqlite.org/atomiccommit.html I don't know that it supports fully ACID (atomic, consist, isolated, durable) transactions or how it handles the various SQL standard transaction isolation levels (Read Uncommitted, Read Committed, Repeatable Read, Serializable) but I believe that updates are atomic and that it does as well as any db (in the face of lying synch. operations, etc...) to handle "non-optimal" stops. g.