From owner-freebsd-questions@FreeBSD.ORG Wed Mar 26 13:09:27 2008 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id C4D59106566B for ; Wed, 26 Mar 2008 13:09:27 +0000 (UTC) (envelope-from wmoran@potentialtech.com) Received: from mail.potentialtech.com (internet.potentialtech.com [66.167.251.6]) by mx1.freebsd.org (Postfix) with ESMTP id 90A228FC1F for ; Wed, 26 Mar 2008 13:09:27 +0000 (UTC) (envelope-from wmoran@potentialtech.com) Received: from vanquish.ws.pitbpa0.priv.collaborativefusion.com (pr40.pitbpa0.pub.collaborativefusion.com [206.210.89.202]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.potentialtech.com (Postfix) with ESMTPSA id 27FA3EBC3B; Wed, 26 Mar 2008 09:09:26 -0400 (EDT) Date: Wed, 26 Mar 2008 09:09:30 -0400 From: Bill Moran To: Da Rock Message-Id: <20080326090930.c8d318ee.wmoran@potentialtech.com> In-Reply-To: <1206495548.6973.161.camel@laptop2.herveybayaustralia.com.au> References: <1206313415.6973.78.camel@laptop2.herveybayaustralia.com.au> <20080323191727.bd9c5237.wmoran@potentialtech.com> <1206315963.6973.84.camel@laptop2.herveybayaustralia.com.au> <34394a3a0803231701n3e125b15nfa866a9dfccfb331@mail.gmail.com> <1206495548.6973.161.camel@laptop2.herveybayaustralia.com.au> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.12.8; i386-portbld-freebsd6.3) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: freebsd-questions@freebsd.org Subject: Re: OT: (Way OT) PHP and MySQL concurrency control using MyISAM tables X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 26 Mar 2008 13:09:27 -0000 In response to Da Rock : [massive snip] > > I remember now exactly why I wanted MyISAM- you see the table locking is > exactly what I need for the task. I just need to come up with a method > to ensure what I send to the server does actually get written- or am I > just being paranoid? > > The task I require needs to offer direct sequential access with no > undoing of written data. And given the legality of the task based on > these strict requirements, you can understand my paranoia. Sounds to me that you want something more like a logfile, where you can write a line of data, then fsync the file to guarantee that it's been committed to disk. Of course, depending on how you'll need to access this data later, this may not be the best approach. I don't know the details of how MySQL does or does not guarantee that your data is safely on disk, but I can say that PostgreSQL uses fsync after each commit to ensure you're data can not be lost. From there, it's up to the hardware, so ensure you have quality disks that don't lie about caching, and you'll probably want a battery-backed RAID controller and some sort of disk redundancy (i.e. RAID-10) -- Bill Moran http://www.potentialtech.com