[OSM-dev] Lite OSM backend

Nicola Ranaldo ranaldo at unina.it
Thu Sep 7 09:01:18 BST 2006

> Oliver has probably thought of this, but there are substantial further
> savings using offsets.

To have a plug&play binary file we need indexes on lat/lon to fast filter 
bounding boxes.  We could release two packages, data only or data + indexes. 
Users could choose and run the full package or the partial (generating 
indexes offline).

About flags, i think 32 bits are not sufficient. We should think about a 
system to extend tags. For example if the  32th is set to 1 then software may 
lookup a special file to find the other tags.
To avoid a large use of this overload area, generating tools should sort tags 
by usage, assign the 31 most used to bits and generate a configuration file 
to get mapping.


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