[OSM-dev] Compression types in PBF Format

[Anthony]

On Wed, Dec 1, 2010 at 9:28 AM, Stefan de Konink <stefan at konink.de> wrote:
> On Wed, 1 Dec 2010, Anthony wrote:
>> LZMA vs. zlib actually makes less of a difference than I thought it would:
>>
>> -rw-r--r-- 1 a a 103M 2010-12-01 08:07 florida.osm.bz2
>> -rw-r--r-- 1 a a 129M 2010-12-01 08:32 florida.osm.gz
>> -rw-r--r-- 1 a a  74M 2010-12-01 08:19 florida.osm.pbf
>> -rw-r--r-- 1 a a 169M 2010-12-01 08:15 florida.osm.rawpbf
>> -rw-r--r-- 1 a a  62M 2010-12-01 08:15 florida.osm.rawpbf.xz
>> -rw-r--r-- 1 a a  86M 2010-11-25 11:29 florida.osm.xz
>>
>> I suspect it would make *much more difference* when it comes to the
>> full history .osm, though.  Does PBF support full history files?  Does
>> Osmosis?
>
> Did you benchmark what pbf + lzma did or did you embed lzma in osmosis?

xz uses lzma.  I made an uncompressed pbf file (florida.osm.rawpbf)
and then compressed it with xz (florida.osm.rawpbf.xz).  This isn't
the same as making a pbf file which uses lzma, but it should be a good
approximation of the compression achievable by embedding lzma in the
pbf.