[OSM-dev] Mapnik doesn't find geometry columns

[Hans Musil]

I'm running mapnik version 0.5.1 as shipped with Debian Lenny. Following 
http://wiki.openstreetmap.org/wiki/Mapnik/Installation#For_Debian_Lenny_or_Sid, 
this should be ready to work.

Also, I have downloaded the latest SVN revision from 
http://svn.openstreetmap.org/applications/rendering/mapnik and done the 
steps described on 
http://wiki.openstreetmap.org/wiki/Mapnik#Rendering_with_Mapnik.

I have imported the extract for the UK 
(http://nick.dev.openstreetmap.org/downloads/planet/uk-090701.osm.bz2) 
with osm2pgsql. No problem with the import and everything looks good in 
the PostGIS db. The following tables are populated with reasonably 
looking data:

 Schema |        Name        | Type  |  Owner
--------------+------------------------+----------+------------
 public | planet_osm_line    | table | hansm
 public | planet_osm_nodes   | table | hansm
 public | planet_osm_point   | table | hansm
 public | planet_osm_polygon | table | hansm
 public | planet_osm_rels    | table | hansm
 public | planet_osm_roads   | table | hansm
 public | planet_osm_ways    | table | hansm


osm=> SELECT * FROM geometry_columns;
 f_table_catalog | f_table_schema |    f_table_name    | 
f_geometry_column | coord_dimension |  srid  |    type
-----------------+----------------+--------------------+-------------------+-----------------+--------+------------
                 | public         | planet_osm_point   | 
way               |               2 | 900913 | POINT
                 | public         | planet_osm_line    | 
way               |               2 | 900913 | LINESTRING
                 | public         | planet_osm_polygon | 
way               |               2 | 900913 | POLYGON
                 | public         | planet_osm_roads   | 
way               |               2 | 900913 | LINESTRING


When trying to render tiles with generate_tiles, I only get PNG files 
with waterbodies and land, but not the actual OSM features. This is 
independend from the zoom level.

When checking my PostgreSQL log files, I see malformed SQL queries 
issued by mapnik. Obviously, it does not know about the tables' geometry 
columns:

select asbinary() as geom,"highway","railway" from
              (select way,highway,railway,
               case when tunnel in ('yes','true','1') then 'yes'::text 
else tunnel end as tunnel
               from planet_osm_roads
               where highway is not null
                  or railway is not null
               order by z_order
              ) as roads
               where  && setSRID('BOX3D(-19724422.27493316 
7200979.560689881,-18472078.00350883 8453323.832114212)'::box3d,537534573)

Now my big question: How do I explain mapnik that it has to use "way" as 
geometry column?

Thanks for helping

Hans