[OSM-dev] Release candidate for OSM binary format is in osmosis trunk.

Peter Körner osm-lists at mazdermind.de
Sun Sep 5 13:02:33 BST 2010

Am 05.09.2010 05:51, schrieb Scott Crosby:
> This schema is more expressive than the current XML which only
> includes a 'source' field in the<bounds>  tag. Should I alter my
> schema to have just one field, 'source'? Or define a mapping between
> this schema and current XML? If I define a mapping, any suggestions as
> to what mapping to define?
I'd suggest to keep your schema, because it's easy to add those new tags 
to the xml schema but not the other way round. And in general more meta 
data is always better, if it's not too expensive (which it isnÄt in your 

The only thing I could imagine to be even better is a key/value list 
instead of those fixed fields. This way we could gather the same 
flexibility as we currently have with the xml.

> My format allows non-geographic metadata, such as username, version
> numbers, and last-modified datestamps to be omitted when generating a
> binary file. This results in significant space savings. However, when
> parsing, Osmosis expects these fields to be supplied. When the
> metadata is omitted, I use '-1' and 'now' as as the default. Other
> suggested defaults?
I'd set the username to an empty string and the ints (version, userid) 
to zero. That would be the natural default. now for the datestamp is 
okay, but as far as I remember osmosis can handle entities without 
parsing the date, so you could supply any string in this case.

> Finally, anyone have any suggestions or comments on the schema or the
> rest of the design?
I really like to have a well defined binary scheme, packaged into nice 
tasks. Thank you for that.


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