[ gpsdrive ] External program interfacing with gpsdrive

[stan]

> we should keep duplication as small as possible (my mapnik database
> containing europe uses almost 2GB...), but performance is also an issue,
> right. I don't know postgis very well, but maybe we can gain some with good
> indexing?
Essential. I'm having a few issues with the bounding box functions on the 
routing data at the mo, it's way to slow because it doesn't seem to be using 
the index.

> how flexible is this system in using one or the other method?
> because I think most people won't need all possible transport types,
> especially if they have limited resources on their devices.
I work it out at around 25MB extra for each transport type on the French data. 
The db for that is a bit over 500MB so roughly 5% bigger for each type. I only 
see 3 types to be relevant, car, cycle and foot. Other options such as 
excluding certain types of road can be implemented on top of this with only a 
minor hit in performance.
So the saving in space by editing the search criteria isn't huge, especially 
now with 8GB in something the size of a euro, the only real benefit is it's 
possible to modify the search methods without re-packaging the entire db or 
using any SQL black arts on the existing data.

> floating point operations? plans?
I have an older version of gpsdrive on my zaurus, bit slow but it works ok. 
It's feeble little ARM processor doesn't know what to do with floating point 
operations, all the new smartphones and pda type things coming out that can 
run linux and use similar processors would benefit from gpsdrive but I don't 
know if there are any plans for an ARM port. With all the extra stuff that has 
gone into mapnik and the osm data this might not even be possible but I'm 
trying to keep it in mind just in case.
cheers