Rendering data base

Principles

Each data rendering process should avoid complex operations on a data base especially when it comes to huge data. OHDM stores a huge amount of data in well-formed data base, see OHDM-Datenmodell. That data model has no redundancy but is hardly basis of a rendering process.

For that reason, we have a rendering data base which is filled from OHDM data. That's not a very new idea, though. It's simply state of the art.

The idea is very simple. We follow OSM in some way and create a table for each imported (and supported) major frature (see OSM-Import-Rules) and geometries. Thus, there is a table for all lines describing highways of any kind. E.g. geological things can be either geometry. There are three tables: geological_points, geological_lines and geological_polygones.

We use GeoServerto produce maps. For each table there is a style, e.g. for geological_points. Each style is associated with a layer and layers can be combined to a layer group. There is a e.g. geological_points layer but also a geological_lines and geological_polygones layer. All those layers are combined to a geological layer.

Each of those (group) layers is offered with GeoServer as WMS. Another group layer combines all layers ans is called basic layer - which is a kind of standard layer for each WMS server.

Our work right now is to produce nice styles and to invent different styles for different ages. Interesting work btw.