simplify very large polygons non used in addresses

Polygons with rank_address = 0 are only used in search and (rarely)
for reverse lookup. Geometries do not need to be precise for that
because topology does not matter. OSM has some very large polygons
of natural features with sizes of more than 10MB. Simplify these
polygons to keep the database and indexes smaller.

lib-sql/functions/utils.sql

@@ -416,6 +416,20 @@ END;
 $$
 LANGUAGE plpgsql IMMUTABLE;
 
+CREATE OR REPLACE FUNCTION simplify_large_polygons(geometry GEOMETRY)
+  RETURNS GEOMETRY
+  AS $$
+BEGIN
+  IF ST_GeometryType(geometry) in ('ST_Polygon','ST_MultiPolygon')
+     and ST_MemSize(geometry) > 3000000
+  THEN
+    geometry := ST_SimplifyPreserveTopology(geometry, 0.0001);
+  END IF;
+  RETURN geometry;
+END;
+$$
+LANGUAGE plpgsql IMMUTABLE;
+
 
 CREATE OR REPLACE FUNCTION place_force_delete(placeid BIGINT)
   RETURNS BOOLEAN