layer:
  id: "road"
  description: Roads
  buffer_size: 4
  srs: +proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over
  fields:
    class: String
  datasource:
    srid: 900913
    query: (SELECT * FROM layer_road(!bbox!, z(!scale_denominator!))) AS t
schema:
  - ./road.sql