[Yum] metadata compression

[Ville Skyttä]

On Sunday 19 April 2009, James Antill wrote:

[sqlite bz2 vs lzma/xz]
> ...which implies somewhere in the 25-35% savings range, but I doubt
> that's enough (on it's own) given the CPU/code requirements.

Regarding CPU requirements, xz/lzma should be much better on metadata consumer 
boxes than bzip2, and somewhat more memory intensive but I doubt this would 
matter much if any at all as long as lzma compression levels are kept at sane 
values.  It is however quite a bit heavier on the metadata producer boxes, 
both CPU and memory wise: http://tukaani.org/lzma/benchmarks .  Whether that's 
a problem depends on the scenario but I'm sure people wouldn't mind being 
given the choice; e.g. even if the CPU/memory requirements would be a problem 
for boxes composing something large like Fedora Rawhide all the time, at least 
for immutable final release repos it should be doable, ditto for many 
scenarios between these extremes.

Regarding code requirements, if yum devs don't feel like implementing it, I'm 
sure the code will just magically appear somewhere if there's a clear green 
light given by the yum devs and when xz and its python bindings reaches a 
stable release.