[osmosis-dev] Proposal for Allowing Additional Data in Pipeline

[Bartosz Fabianowski]

Additional meta data will also enable much more flexible filters. Right 
now, if you want to find all nodes, ways and relations carrying a 
particular tag plus the primitives referenced by these, you have to set 
up three copies of the input stream, filtering each separately and then 
merging the results. With additional meta data, you could easily chain 
the required filters into a single pipeline, passing information about 
which ways/nodes/relations have been selected via an additional flag. In 
this case, the additional meta data would used internally and would not 
get stored in the resulting OSM file.

In the use cases you described, the OSM file receives the meta data. 
Note that for the PBF format, this will require extending the protocol 
definition.

- Bartosz