Re: Git and OpenDocument (OpenOffice.org) files

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Aug 27, 2007, 14:15 UTC
Message-ID: <Pine.LNX.4.64.0708271510060.28586@racer.site>
In-Reply-To: <vpqr6lpvzqc.fsf@bauges.imag.fr>

Hi,

On Mon, 27 Aug 2007, Matthieu Moy wrote:

Show 15 quoted lines

> David Kastrup <dak@gnu.org> writes:
> 
> > Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:
> >
> >> On Mon, 27 Aug 2007, Mike Hommey wrote:
> >>
> >>> BTW, wouldn't it be more efficient to store the odf files unzipped ?
> >>
> >> Efficient how?  Speed-wise: no.  Space-wise: yes.
> >
> > Huh?  At least the "Space-wise: yes" seems rather nonsensical.
> 
> I don't know enough about git delta-compression and OpenDocument, but 
> git has better chance to efficiently delta-compress different versions 
> of the document if they're not compressed themselves.

A standalone zip archive (which is what an .odt file is, with a defined file structure) cannot be as efficient in compressing text, especially if it is versioned text with relatively few differences between versions, as delta compression.

So yes, you guessed the explanation (which I omitted) correctly.

As for the speed wise: I doubt that unpacking and then repacking can be more efficient than not doing it -- even if the files are transmitted via network. (Remember: blobs are stored compressed, be they in a pack, or loose.)

Ciao, Dscho