[gdal-dev] OSM driver to create separate tables for tags

[Jukka Rahkonen]

Andre Joost <andre+joost <at> nurfuerspam.de> writes:

> 
> But import time does not matter for me , as it is done only once. I was 
> rather thinking about rendering time. From the postgis database, I can 
> select a column "network" and style my cycle paths according to the 
> values "icn","ncn","rcn","lcn". Pretty much the same as I would do it 
> with a shapefile.
> 
> I guess this needs different handling with your tag table approach.


Couple of years ago I was told that such arrangement would be all too slow
for rendering https://groups.google.com/forum/#!topic/openstreetmap/aslKT7-OcLQ
I did not believe and I made some experiments and measured that in my
rendering test joined tables were faster than the standard osm2pgsql tables.
Not a surprise for me because osm2pgsql does not create indexes for the
attribute columns but my renderer was using them in selects. In the tag
table I had indexes on all columns. I prepered a test Spatialite DB then and
it is still online at http://latuviitta.org/documents/relation_test.zip


-Jukka Rahkonen-