[OSM-talk] mapnik does not display symbols

[Jon Burgess]

On Tue, 2009-03-10 at 06:26 +0530, Kenneth Gonsalves wrote:
> On Tuesday 10 March 2009 00:19:03 you wrote:
> > The most likely problem is that you have not used an up to date copy of
> > default.style when running the osm2pgsql import. If so, you may be
> > missing some of the columns in the DB tables and Mapnik will silently
> > fail to render any layer which references the missing data.
> 
>  I did not see any mention anywhere of default.style when running the import - 
> could you elaborate please.

osm2pgsql has the following option:
   -S|--style           Location of the style file. Defaults to ./default.style

The default.style file has a list of the keys which it will import into
the postgresql database like:

node,way   admin_level  text         linear
node,way   aerialway    text         linear
node,way   aeroway      text         polygon
node,way   amenity      text         nocache,polygon

There is a better description of this file in the comments [1].

As new fields are added into the osm.xml, each new column must be added
into the default.style too. To use the latest osm.xml you also need to
use the latest default.style when importing the data.

        Jon

1: http://trac.openstreetmap.org/browser/applications/utils/export/osm2pgsql/default.style