+-- Compute a base address rank from the extent of the given geometry.
+--
+-- 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)
+ RETURNS SMALLINT
+ AS $$
+DECLARE
+ area FLOAT;
+BEGIN
+ IF ST_GeometryType(geometry) in ('ST_Polygon','ST_MultiPolygon') THEN
+ area := ST_Area(geometry);
+ ELSIF ST_GeometryType(geometry) in ('ST_LineString','ST_MultiLineString') THEN
+ area := (ST_Length(geometry)^2) * 0.1;
+ ELSE
+ RETURN search_rank;
+ END IF;
+
+ IF area > 1 THEN
+ RETURN 7;
+ ELSIF area > 0.1 THEN
+ RETURN 9;
+ ELSIF area > 0.01 THEN
+ RETURN 13;
+ ELSIF area > 0.001 THEN
+ RETURN 17;
+ ELSIF area > 0.0001 THEN
+ RETURN 19;
+ ELSIF area > 0.000005 THEN
+ RETURN 21;
+ END IF;
+
+ RETURN 23;
+END;
+$$
+LANGUAGE plpgsql IMMUTABLE;
+