guess a base address level for address rank 0 objects

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

diff --git a/sql/functions/ranking.sql b/sql/functions/ranking.sql
index ecd31e90d03e81d3629f0c92d2b77296483a884d..e918f924d9e0771537c01ac9baaf0520d88409d7 100644 (file)
--- a/sql/functions/ranking.sql
+++ b/sql/functions/ranking.sql
@@ -55,6 +55,44 @@ END;
 $$
 LANGUAGE plpgsql IMMUTABLE;
 
+-- 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;
+
 
 -- Guess a ranking for postcodes from country and postcode format.
 CREATE OR REPLACE FUNCTION get_postcode_rank(country_code VARCHAR(2), postcode TEXT,
@@ -114,3 +152,75 @@ BEGIN
 END;
 $$
 LANGUAGE plpgsql IMMUTABLE;
+
+
+-- Get standard search and address rank for an object.
+--
+-- \param country        Two-letter country code where the object is in.
+-- \param extended_type  OSM type (N, W, R) or area type (A).
+-- \param place_class    Class (or tag key) of object.
+-- \param place_type     Type (or tag value) of object.
+-- \param admin_level    Value of admin_level tag.
+-- \param is_major       If true, boost search rank by one.
+-- \param postcode       Value of addr:postcode tag.
+-- \param[out] search_rank   Computed search rank.
+-- \param[out] address_rank  Computed address rank.
+--
+CREATE OR REPLACE FUNCTION compute_place_rank(country VARCHAR(2),
+                                              extended_type VARCHAR(1),
+                                              place_class TEXT, place_type TEXT,
+                                              admin_level SMALLINT,
+                                              is_major BOOLEAN,
+                                              postcode TEXT,
+                                              OUT search_rank SMALLINT,
+                                              OUT address_rank SMALLINT)
+AS $$
+DECLARE
+  classtype TEXT;
+BEGIN
+  IF place_class in ('place','boundary')
+     and place_type in ('postcode','postal_code')
+  THEN
+    SELECT * INTO search_rank, address_rank
+      FROM get_postcode_rank(country, postcode);
+  ELSEIF extended_type = 'N' AND place_class = 'highway' THEN
+    search_rank = 30;
+    address_rank = 0;
+  ELSEIF place_class = 'landuse' AND extended_type != 'A' THEN
+    search_rank = 30;
+    address_rank = 0;
+  ELSE
+    IF place_class = 'boundary' and place_type = 'administrative' THEN
+      classtype = place_type || admin_level::TEXT;
+    ELSE
+      classtype = place_type;
+    END IF;
+
+    SELECT l.rank_search, l.rank_address INTO search_rank, address_rank
+      FROM address_levels l
+     WHERE (l.country_code = country or l.country_code is NULL)
+           AND l.class = place_class AND (l.type = classtype or l.type is NULL)
+     ORDER BY l.country_code, l.class, l.type LIMIT 1;
+
+    IF search_rank is NULL THEN
+      search_rank := 30;
+    END IF;
+
+    IF address_rank is NULL THEN
+      address_rank := 30;
+    END IF;
+
+    -- some postcorrections
+    IF place_class = 'waterway' AND extended_type = 'R' THEN
+        -- Slightly promote waterway relations so that they are processed
+        -- before their members.
+        search_rank := search_rank - 1;
+    END IF;
+
+    IF is_major THEN
+      search_rank := search_rank - 1;
+    END IF;
+  END IF;
+END;
+$$
+LANGUAGE plpgsql IMMUTABLE;