ThanksĀ Frederik! I will giveĀ osm2pgsql a try. Any recommended URL where I can start reading about the "style file" approach to only load boundaries?
Nic Am Donnerstag, den 28.12.2017, 11:19 +0100 schrieb Frederik Ramm: > Hi, > > On 28.12.2017 10:37, Nic wrote: > > > > I want to generate a polygon out of the different members/ways of > > an > > administrative relation (e.g. Bundesland). > > For that purpose I have loaded a pbf file via osmosis into a > > postgresql/postgis database. > That makes things unnecessarily difficult. Use osm2pgsql to load the > data instead, and the polygons will be built for you. You can even > use a > so-called "style file" with osm2pgsql that will only import > boundaries, > leaving out roads, buildings etc., which will speed up the process a > lot. > > > > > However it seem that the random order of relation members causes > > trouble generating a "simplified" (st_linemerge) linestring > > suitable to > > apply the st_makepolygon funktion to it. > If you insist on continuing down your path, then st_polygonize would > be > the function to use (it does not depend on the ordering of segments), > but osm2pgsl is really the better approach because it builds the > polygons on a "topological" level (using OSM node IDs) instead of on > the > geometric level (looking only at coordinates). > > Bye > Frederik > _______________________________________________ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk