[mkgmap-dev] New locator branch

Fri Mar 18 13:45:57 GMT 2011

Yes, we provide the same option for coastlines. So it's possible 
although there is the size restriction.
Boundaries take around 3% of the complete OSM data (3% as osm.gz 
compared to osm.pbf). So think about creating a europe map from the 4.5 
GB dump. The boundary data file would be around 3%*4.5GB(osm.pbf) = 
135MB(osm.gz). So in the end your computer additionally needs as much 
main memory as you need to compile a 135MB big tile.

The calculation is quite rough but the result is clear: the memory 
requirements grow quite much compared to the overall size of your map.

WanMil

> Stupid question...
> Why don't extract the boundaries with osmosis to a single file.
> mkgmap could use this file to complete the boundaries while rendering the maps...
>
> Martin
>
> Am 17.03.2011 um 22:57 schrieb WanMil:
>
>>
>>>
>>>> And another requirement is also hard to achieve: performance. The branch
>>>> is not optimized very well yet. But I am sure that such searches for big
>>>> areas from all items of a tile are quite expensive no matter how
>>>> optimized they are.
>>>>
>>>> WanMil
>>>> _______________________________________________
>>>>
>>> I currently really don't want to use the locator branch, due to it's
>>> speed. I need already about 12 hours to compute all maps for weekly
>>> updates and osm data alone growing is already a concern. Wouldn't it be
>>> enough to use no guessing and just input correct addresses (best with
>>> working housenumber search)? The searching for streets not addresses is
>>> anyhow kinda strange and seems much more like a workaround than a clean
>>> solution.
>>
>> Yes ... but how should mkgmap input the correct addresses? ;-)
>> In an ideal world you are right. But OSM data is far (very far) away
>> from complete address tagging.
>>
>> Beware that all POIs would have to contain a complete set of addr-tags
>> (addr:country, addr:county addr:region(?), addr:city, addr:street,
>> addr:housenumber). The same with the is_in tags for all streets that do
>> not have any POIs attached until now. I havn't tested it but it should
>> not be too complicated to make a statistic with osmosis and a dump file.
>>
>> Maybe the completeness of tagging will change within the next 2 years
>> but we are implementing for now.
>>
>> WanMil