Merge scaleranks for countries and states

layers/place/merge_country_rank.sql

@@ -0,0 +1,26 @@
+WITH important_country_point AS (
+    SELECT osm.geometry, osm.osm_id, osm.name, COALESCE(NULLIF(osm.name_en, ''), ne.name) AS name_en, ne.labelrank
+    FROM ne_10m_admin_0_countries AS ne, osm_country_point AS osm
+    WHERE
+    -- We only match whether the point is within the Natural Earth polygon
+    -- because name matching is to difficult since OSM does not contain good
+    -- enough coverage of ISO codes
+    ST_Within(osm.geometry, ne.geom)
+    -- We leave out tiny countries
+    AND ne.scalerank <= 1
+)
+UPDATE osm_country_point AS osm
+-- We merge the labelrank not scalerank because it is more fine grained
+-- and allows styling more important countries bigger than others
+SET "rank" = ne.labelrank
+FROM important_country_point AS ne
+WHERE osm.osm_id = ne.osm_id;
+
+UPDATE osm_country_point AS osm
+SET "rank" = 6
+WHERE "rank" <= 0 OR "rank" > 6 OR "rank" IS NULL;
+
+ALTER TABLE osm_country_point DROP CONSTRAINT IF EXISTS osm_country_point_rank_constraint;
+ALTER TABLE osm_country_point ADD CONSTRAINT osm_country_point_rank_constraint CHECK("rank" BETWEEN 1 AND 6);
+
+CREATE INDEX IF NOT EXISTS osm_country_point_rank_idx ON osm_country_point("rank");