Marcus Wolschon schrieb: > On Wed, Jul 22, 2009 at 4:25 PM, Andreas Kalsch<[email protected]> wrote: > >> I don't render maps with it, so I don't know how it scales. But Mapnik >> will connect easier to Postgres/PostGIS. I will outsource rendering for >> my project. >> > > Note: I don`t use Mapnik. I was talking about _interactive_ rendering. > It`s a routing-application and I`m just testing if offering MySQL as an > additional supported local map-format works out. Other offered > formats are OsmBin, the H2-embedded database, xml-files (for testing), > in-memory, .... > OK, I am sure this is scalable - but you should compare yourself. Haven't done that so far. > >>> Can you decompose a POINT into lat+lon in an SQL-query? >>> If not, how much space is wasted by having all coordinates >>> twice? >>> >>> >> Yes. >> > > Yes - you can decomposit them or > Yes - with X() and Y() > Yes - you have to store a Point AND Lat+Lon as separate columns? > No - you don't have to. But I store them separately into two tables because I don't want all nodes to be gisified. Using lat/lon as int will need 8 bytes. Using a Point will use 20 bytes. So if you don't need to index a point, save it as lat/lon. > >> But I just put relevant features into the geo database - I save >> nodes and ways which have relevant tags, and relations as >> GeometryCollections and MultiPolygons. It makes no sense to put nodes >> and ways into the GIS table, which are just parts of ways/relations and >> do not play an own role. Result: 5 of 17.3 GB (for Europe) is for GIS >> data. I use the GIS table for analysis and re-computing. It pays off. >> > > How much would that be without filtering? Since I have no clue what > are "relevant tags and relations" for you. > Relevant features are features which represent a GeoObject. Nodes which are just part of ways and ways which are just part of multipolygons are not relevant in this context.
How many features are relevant as their own: - nodes 4 % - ways 99 % - relations 81 % _______________________________________________ dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/dev
