Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758756Ab0FVBeQ (ORCPT ); Mon, 21 Jun 2010 21:34:16 -0400 Received: from kaylee.flamingspork.com ([74.207.245.61]:48518 "EHLO kaylee.flamingspork.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752568Ab0FVBeO (ORCPT ); Mon, 21 Jun 2010 21:34:14 -0400 X-Greylist: delayed 476 seconds by postgrey-1.27 at vger.kernel.org; Mon, 21 Jun 2010 21:34:14 EDT From: Stewart Smith To: David Pottage , Nikanth Karthikesan Cc: OGAWA Hirofumi , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Alexander Viro , Christoph Hellwig , Chris Mason , linux-btrfs@vger.kernel.org Subject: Re: [PATCH][RFC] Complex filesystem operations: split and join In-Reply-To: References: <201006092035.46481.knikanth@novell.com> <87aaqzp39a.fsf@devron.myhome.or.jp> <201006151611.36443.knikanth@novell.com> User-Agent: Notmuch/0.3.1-54-g42e146a (http://notmuchmail.org) Emacs/23.1.1 (x86_64-pc-linux-gnu) Date: Tue, 22 Jun 2010 09:26:16 +0800 Message-ID: <87fx0fuabr.fsf@willster.local.flamingspork.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1183 Lines: 25 On Tue, 15 Jun 2010 16:16:06 +0100, "David Pottage" wrote: > On the other hand, perhaps databases such as SQLite or MySQL would > benifit from this feature for improving their backend storage, especaly > if large amounts of BLOB data is inserted or deleted? unlikely. 1) these operations aren't available everywhere 2) kind of incompatible with how things are stored now 3) no doubt incredibly fun with high concurrency (readers streaming out BLOBs from later in the file while you go and change everything) 4) a background thread that goes around repacking things if you need to trim the end off the file just isn't that bad. (sure, a nice api call to 'instantly' copy/swap parts of a file could be fun... but then it's relying on the OS and file system to get this right... which is almost always a bad idea) cheers, Stewart "spending way too much time inside databases to maintain sanity" Smith -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/