From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Sixt Subject: Re: How Blobs Work ( Blobs Vs. Deltas) Date: Tue, 30 Sep 2008 17:29:08 +0200 Message-ID: <48E245C4.7030003@viscovery.net> References: <16946e800809300814v134a42dft37becdbd8aa7669a@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: git@vger.kernel.org To: Feanil Patel X-From: git-owner@vger.kernel.org Tue Sep 30 17:30:32 2008 connect(): Connection refused Return-path: Envelope-to: gcvg-git-2@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by lo.gmane.org with esmtp (Exim 4.50) id 1KkhB8-0000kU-6m for gcvg-git-2@gmane.org; Tue, 30 Sep 2008 17:30:22 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752923AbYI3P3M (ORCPT ); Tue, 30 Sep 2008 11:29:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752922AbYI3P3M (ORCPT ); Tue, 30 Sep 2008 11:29:12 -0400 Received: from lilzmailso02.liwest.at ([212.33.55.13]:35475 "EHLO lilzmailso02.liwest.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752907AbYI3P3M (ORCPT ); Tue, 30 Sep 2008 11:29:12 -0400 Received: from cm56-163-160.liwest.at ([86.56.163.160] helo=linz.eudaptics.com) by lilzmailso02.liwest.at with esmtpa (Exim 4.66) (envelope-from ) id 1Kkh9w-00072y-E6; Tue, 30 Sep 2008 17:29:08 +0200 Received: from [127.0.0.1] (J6T.linz.viscovery [192.168.1.42]) by linz.eudaptics.com (Postfix) with ESMTP id 2D8E84FB; Tue, 30 Sep 2008 17:29:08 +0200 (CEST) User-Agent: Thunderbird 2.0.0.6 (Windows/20070728) In-Reply-To: <16946e800809300814v134a42dft37becdbd8aa7669a@mail.gmail.com> X-Spam-Score: 1.7 (+) X-Spam-Report: ALL_TRUSTED=-1.8, BAYES_99=3.5 Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Feanil Patel schrieb: > I was reading about git objects on The Git > Book(http://book.git-scm.com/1_the_git_object_model.html) which was > posted on the mailing list a while back and I was wondering something > about blobs and how files are stored in any particular version. If > file A is changed from version one to version two there are two > different blobs that exist for the two versions of the file, is that > correct? The Book was saying Git does not use delta storage so does > this mean that there are two almost identical copies of the file with > the difference being the change that was put in from version one to > version two? At the conceptual level, yes. An entire file (== blob) is the smallest unit that you can address. Even git's internals do not work with smaller units. But there is, of course, a mechanism that stores the database in a more compact format, the so-called pack files, that basically store differences between files as much as possible. -- Hannes