Wrap place UNIONs into one SELECT to sppeed up rendering

layers/place/city.sql

@@ -5,6 +5,7 @@
 -- etldoc: osm_city_point -> layer_city:z2_14
 CREATE OR REPLACE FUNCTION layer_city(bbox geometry, zoom_level int, pixel_width numeric)
 RETURNS TABLE(osm_id bigint, geometry geometry, name text, name_en text, name_de text, tags hstore, place city_place, "rank" int, capital int) AS $$
+  SELECT * FROM (
     SELECT osm_id, geometry, name,
     COALESCE(NULLIF(name_en, ''), name) AS name_en,
     COALESCE(NULLIF(name_de, ''), name, name_en) AS name_de,
@@ -49,5 +50,6 @@ RETURNS TABLE(osm_id bigint, geometry geometry, name text, name_en text, name_de
        OR (zoom_level = 9 AND (gridrank <= 8 OR "rank" IS NOT NULL))
        OR (zoom_level = 10 AND (gridrank <= 12 OR "rank" IS NOT NULL))
        OR (zoom_level BETWEEN 11 AND 12 AND (gridrank <= 14 OR "rank" IS NOT NULL))
-       OR (zoom_level >= 13);
+       OR (zoom_level >= 13)
+  ) as city_all;
 $$ LANGUAGE SQL IMMUTABLE;

layers/place/layer.sql

@@ -6,6 +6,7 @@ CREATE OR REPLACE FUNCTION layer_place(bbox geometry, zoom_level int, pixel_widt
 RETURNS TABLE(osm_id bigint, geometry geometry, name text, name_en text,
     name_de text, tags hstore, class text, "rank" int, capital INT, iso_a2
         TEXT) AS $$
+    SELECT * FROM (
 
     -- etldoc: osm_continent_point -> layer_place:z0_3
     SELECT
@@ -94,4 +95,5 @@ RETURNS TABLE(osm_id bigint, geometry geometry, name text, name_en text,
         NULL::text AS iso_a2
     FROM layer_city(bbox, zoom_level, pixel_width)
     ORDER BY "rank" ASC
+    ) AS place_all
 $$ LANGUAGE SQL IMMUTABLE;