[OSM-dev] Compression types in PBF Format

[Stefan de Konink]

On Wed, 1 Dec 2010, Anthony wrote:

>> Yeah, but your lead basically shows we are talking about more than 10%...
>
> Yeah, probably, but at the expense of more complicated code, greater
> memory usage, etc.

The hole process is IO-bound... memory is used anyway to overcome the IO 
issues...

> I'm interested now in seeing how the full history compression goes,
> though.  If it can achieve 70, 80, 90% on top of zlib, then it might
> be worth embedding the compression as opposed to just using it for
> transfer over the Internet.

The dictionary is compressed per block, so it greatly depends if the trick 
works.


Stefan