[Geocoding] Does Nominatim need all OSM data to be efficient ?

[datendelphin]

Hi

On 03.04.2012 10:32, Charles DESNEUF wrote:
> Hi
> Thank you for your answer.
> I used Osmosis to create a filtered version of the planet file with
> the following syntax :
>
> osmosis --rb FILE --tag-filter accept-ways boundary=* border_type=*
> place=* --used-node outPipe.0=ways
> --rb FILE --tf accept-nodes boundary=* border_type=* place=*
> outPipe.0=nodes
> --merge inPipe.0=ways inPipe.1=nodes --wb filtered.pbf
>
> According to Osmosis usage
> ( http://wiki.openstreetmap.org/wiki/Osmosis/Detailed_Usage#--tag-filter_.28--tf.29 )
> this command preserves relations. Am I right ?
>
I am no osmosis guru, so I can not say much about this. My feeling is
you should include the appropriate relations explicitly, because almost
all information you need will be stored in relations. If for some reason
osm2pgsql can not construct a closed boundary from the relations
(because points ore ways are missing), the results will be unusable.

> As we discussed my issue on the dev fr ML we pointed out that I forgot
> to include admin_level tags. This might be the reason.
>
This will surely help that the ways the boundary relations point to are
included.

Anyway, make a simple example. You used Moscow in the previous mail.
That would be relation 102269. See if it turns up in your placex table.
If not, you've got a problem with filtering.

To make this small test, you can use utils/update.php --import-relation
102269 on an existing nominatim Database to import only this relation

Also the output of your details page for Moscow would be interesting to see.

Datendelphin