-- Верификация масштаба дистанций: mercator vs geography (Браслав)
WITH s AS (
  SELECT ST_Transform(ST_SetSRID(ST_MakePoint(27.03, 55.64), 4326), 3857) AS c_m,
         ST_SetSRID(ST_MakePoint(27.03, 55.64), 4326) AS c_g
)
SELECT
  (SELECT MIN(ST_Distance(p.way, c_m)) FROM planet_osm_polygon p, s
     WHERE (p."natural"='water' OR p.landuse='reservoir') AND p.way && ST_Expand(s.c_m, 30000)) AS merc_m,
  (SELECT MIN(ST_Distance(ST_Transform(p.way, 4326)::geography, c_g::geography)) FROM planet_osm_polygon p, s
     WHERE (p."natural"='water' OR p.landuse='reservoir') AND p.way && ST_Expand(s.c_m, 30000)) AS geo_m;