CREATE OR REPLACE FUNCTION search_bottlenecks(search_string text) RETURNS jsonb
  LANGUAGE plpgsql STABLE PARALLEL SAFE
  AS $$
DECLARE
  _result jsonb;
BEGIN
  SELECT COALESCE(json_agg(r),'[]')
    INTO _result
    FROM (SELECT objnam AS name,
                 ST_AsGeoJSON(ST_Envelope(area::geometry))::json AS geom,
                 'bottleneck' AS type
            FROM waterway.bottlenecks
            WHERE objnam ILIKE '%' || search_string || '%'
              AND validity @> now()
          ORDER BY name) r;
  RETURN _result;
END;
$$;