[OSM-dev] comparing two planet files

Stephan Knauss osm at stephans-server.de
Wed Jan 5 00:21:08 GMT 2011


Hi,

I did some experiments comparing osmosis applying diffs and osmchange.

I started with th 20101229 planet.

the merged.osc contains four days of OSC merged and simplify-change with 
osmosis.

Then I let both tools apply the diff.
osmosis and osmchange.

First I wondered that both resulting files got smaller.
Is removing the source tag saving this much?

   2.190.304.683 merged.osc
210.012.837.920 planet-20101229.osm
206.896.888.563 planet-20110102.osm
208.625.319.736 planet-20110102.osm.osmchange


I tried counting the actions inside the osc:
#perl ..\count-osc.pl
505547 elements will be deleted
8200263 elements will be created


So let's assume the file will get smaller. I now wonder why it differs 
that much depending on the tool applying the diff.

What tool could be used to diff the generated osm files? diff just tells 
me "out of memory"

I would like to know what data was missing.


Any ideas?

Stephan



More information about the dev mailing list