Changing dpkg-deb default compression from gzip to lzma for Hardy

[Aaron Whitehouse]

On 18/12/2007, Mario Vukelic <mario.vukelic at dantian.org> wrote:
> A while ago I read about changing apt/dpkg to allow for the handling of
> security updates through binary patches. Does anyone know what came out
> of this?

https://wiki.ubuntu.com/apt-sync

On the main issue, https://wiki.ubuntu.com/Dpkg7Zip gives (in a spec
that is from 2005) a bit more background. Note that the application is
7zip and the algorithm that most talk about is LZMA.

As stated on that page, some useful links on this issue are:
http://en.wikipedia.org/wiki/7z (archive format)
http://en.wikipedia.org/wiki/LZMA
http://tukaani.org/lzma/

It seems sensible to me to use a format for the packages that trades
off compression time for archives that are as small and quick to
decompress as possible. The compression is only done once, but the
benefits in downloading time/cost and decompression speed are enjoyed
by thousands.

As far as I can see,  the only people whose downloading +
decompression time is likely to be longer using LZMA are those who
have an old processor *and* an incredibly slick (network?) connection
to the archive. These people may suffer an extra minute or so of
decompression time for a 100MB file (on the figures that I have seen).
This has to be weighed against the time and cost savings for everybody
else, plus the reduction in pressure on mirrors and the CD.

I hope this background helps the discussion,

Aaron

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