layer:
  id: "aeroway"
  description: |
      Aeroway polygons based of OpenStreetMap [aeroways](http://wiki.openstreetmap.org/wiki/Aeroways).
      Airport buildings are contained in the **building** layer but all
      other airport related polygons can be found in the **aeroway** layer.
  buffer_size: 4
  fields:
    class:
      description: |
          The original value of the [`aeroway`](http://wiki.openstreetmap.org/wiki/Key:aeroway) tag.
      values:
      - aerodrome
      - heliport
      - runway
      - helipad
      - taxiway
      - apron
  datasource:
    geometry_field: geometry
    query: (SELECT geometry, class FROM layer_aeroway(!bbox!, z(!scale_denominator!))) AS t
schema:
  - ./layer.sql
datasources:
  - type: imposm3
    mapping_file: ./mapping.yaml