Glossary¶
OSM-specific terms you'll encounter when working with this project.
OSM relation ID¶
Every city, district, or region in OpenStreetMap has a numeric ID called a relation ID. spieli uses this ID to know which geographic area to show on the map.
To find the relation ID for your region: search on Nominatim or openstreetmap.org — it appears in the URL, e.g. openstreetmap.org/relation/62700 → ID is 62700.
PBF file¶
A PBF file (Protocolbuffer Binary Format) is a compressed snapshot of OpenStreetMap data for a geographic region. Geofabrik publishes regularly-updated PBF extracts at download.geofabrik.de.
The importer reads a PBF file to populate the database. The file only needs to contain your region — a Bundesland extract works for a single Kreis within it.
osm2pgsql¶
osm2pgsql is the tool that reads a PBF file and imports the OSM data into PostgreSQL. You run it via make import to load data for the first time, and again whenever you want to refresh from a newer Geofabrik extract.
More: osm2pgsql.org
PostgREST¶
PostgREST is a server that automatically turns a PostgreSQL database into a REST API. Instead of writing server-side code, you write SQL functions and PostgREST exposes them as HTTP endpoints. spieli's entire API layer is PostgREST — there is no custom backend application server.
More: postgrest.org
Data Quality indicator¶
Each playground carries a Data Quality badge whose colour reflects how completely it has been mapped in OpenStreetMap:
| Colour | Legend label | Meaning |
|---|---|---|
| Green | hoch / high | Photos, a name, and at least one detail (equipment, surface, …) are present |
| Yellow | mittel / medium | At least one of the above is present, but not all |
| Red | niedrig / low | None of the above — the playground exists in OSM but has no additional data |
The map legend is headed "Datenqualität" / "Data Quality" and uses short scale labels (hoch / mittel / niedrig). The panel badge also reads "Datenqualität" / "Data Quality" in the matching colour. The same three-state breakdown is used in cluster rings and the federation macro view.
Internally, the three states are referred to as complete, partial, and missing. These values appear in the API responses (see api.md) and in the database (playground_stats materialised view). The display label is intentionally kept neutral — it describes what is shown, not a judgement.
Overpass Turbo¶
Overpass Turbo (overpass-turbo.eu) is a web tool for running ad-hoc queries against live OpenStreetMap data. It is useful when adding support for a new device type — you can search for playground=<tag> to find real playgrounds that have the device mapped and use them for testing.