Re: On Tracking Binary Files

From: Nicolas Pitre <nico@cam.org>
Date: Apr 14, 2009, 19:42 UTC
Message-ID: <alpine.LFD.2.00.0904141532160.6741@xanadu.home>
In-Reply-To: <7efce40a0904140742i48aad41ds66de5dfe368f3b16@mail.gmail.com>

On Tue, 14 Apr 2009, Patrick Berkeley wrote:

> Does Git track the deltas on binary files?

Yes. And actually git's delta storage doesn't care at all whether a file is text or binary.

> Someone in #git mentioned that if the binaries change too much Git no 
> longer just stores the changes. If this is the case, what is the 
> breaking point where Git goes from storing the deltas to the entire 
> new file?

If two versions of the same file are simply too different to make delta compression worth it, then no deltas are used. It is still possible that a third version of the same file would produce a nice delta against either the first or second version though, in which case that third version will be stored as a delta. And so on.

A sophisticated set of euristics is applied to the list of objects as a whole to determine the best delta arrangement possible. So there is no such thing as a simple "breaking point".

Nicolas