use different area estimates for large countries

[nominatim.git] / sql / functions / ranking.sql

diff --git a/sql/functions/ranking.sql b/sql/functions/ranking.sql
index e918f924d9e0771537c01ac9baaf0520d88409d7..a84269fe6730669b6c805a0bb632b645c87f1199 100644 (file)
--- a/sql/functions/ranking.sql
+++ b/sql/functions/ranking.sql
@@ -60,7 +60,7 @@ LANGUAGE plpgsql IMMUTABLE;
 -- This is all simple guess work. We don't need particularly good estimates
 -- here. This just avoids to have very high ranked address parts in features
 -- that span very large areas (or vice versa).
-CREATE OR REPLACE FUNCTION geometry_to_rank(search_rank SMALLINT, geometry GEOMETRY)
+CREATE OR REPLACE FUNCTION geometry_to_rank(search_rank SMALLINT, geometry GEOMETRY, country_code TEXT)
   RETURNS SMALLINT
   AS $$
 DECLARE
@@ -74,6 +74,15 @@ BEGIN
     RETURN search_rank;
   END IF;
 
+  -- adjust for the fact that countries come in different sizes
+  IF country_code IN ('ca', 'au', 'ru') THEN
+    area := area / 5;
+  ELSIF country_code IN ('br', 'kz', 'cn', 'us', 'ne', 'gb', 'za', 'sa', 'id', 'eh', 'ml', 'tm') THEN
+    area := area / 3;
+  ELSIF country_code IN ('bo', 'ar', 'sd', 'mn', 'in', 'et', 'cd', 'mz', 'ly', 'cl', 'zm') THEN
+    area := area / 2;
+  END IF;
+
   IF area > 1 THEN
     RETURN 7;
   ELSIF area > 0.1 THEN