From: Dmitry Potapov <dpotapov@gmail.com>
Date: Sat, 17 Apr 2010 10:40:37 GMT
Subject: Re: GIT Performance question
Message-ID: <20100417104037.GA20631@dpotapov.dyndns.org>
In-Reply-To: <1271498149921-4917066.post@n2.nabble.com>

On Sat, Apr 17, 2010 at 01:55:49AM -0800, santos2010 wrote:
> 
> I read that GIT doesn't use deltas, it uses snapshots. My question is: how
> could GIT have high performance (most of the users say that) if for
> synchronization (pull/push command) with e.g. a shared repository GIT
> transfers all modified files (and references) instead of the respective
> deltas? 

Well, Git _does_ use deltas for storage and synchronization, but this
deltas are unrelated to history of changes stored in the repository. So,
conceptually, Git just stores snapshots, but files in those snapshots
are deltified against some old files based on some heuristic of finding
similar files, which allows Git to create deltas not only to previous
version of the same file (which most VCSes do), but potentially to any
file stored in the repository if it similar enough. So, typically, Git
has the most compact storage comparing to other VCSes, in particular, in
case of complex history with a lot of branches and merges.


Dmitry