Merge pull request #3926 from lonvia/rework-postcode-handling

Reorganise postcode handling

Author: lonvia

docs/customize/Import-Styles.md

@@ -113,6 +113,7 @@ The following classifications are recognized:
 | named           | Consider as main tag, when the object has a primary name (see [names](#name-tags) below) |
 | named_with_key  | Consider as main tag, when the object has a primary name with a domain prefix. For example, if the main tag is  `bridge=yes`, then it will only be added as an extra entry, if there is a tag `bridge:name[:XXX]` for the same object. If this property is set, all names that are not domain-specific are ignored. |
 | fallback        | Consider as main tag only when no other main tag was found. Fallback always implies `named`, i.e. fallbacks are only tried for objects with primary names. |
+| postcode_area   | Tag indicates a postcode area. Copy area into the table of postcodes but only when the object is a relation and has a postcode tagged. |
 | delete          | Completely ignore the tag in any further processing |
 | extra           | Move the tag to extratags and then ignore it for further processing |
 | `<function>`| Advanced handling, see [below](#advanced-main-tag-handling) |

docs/develop/Database-Layout.md

@@ -79,7 +79,7 @@ the placex table. Only three columns are special:
 Address interpolations are always ways in OSM, which is why there is no column
 `osm_type`.
 
-The **location_postcode** table holds computed centroids of all postcodes that
+The **location_postcodes** table holds computed centroids of all postcodes that
 can be found in the OSM data. The meaning of the columns is again the same
 as that of the placex table.
 

docs/develop/search-tables.plantuml

@@ -74,15 +74,16 @@ map place_addressline {
   isaddress => BOOLEAN
 }
 
-map location_postcode {
+map location_postcodes {
   place_id => BIGINT
+  osm_id => BIGINT
   postcode => TEXT
   parent_place_id => BIGINT
   rank_search => SMALLINT
-  rank_address => SMALLINT
   indexed_status => SMALLINT
   indexed_date => TIMESTAMP
   geometry => GEOMETRY
+  centroid -> GEOMETRY
 }
 
 placex::place_id <-- search_name::place_id
@@ -94,6 +95,6 @@ search_name::nameaddress_vector --> word::word_id
 
 place_addressline -[hidden]> location_property_osmline
 search_name -[hidden]> place_addressline
-location_property_osmline -[hidden]-> location_postcode
+location_property_osmline -[hidden]-> location_postcodes
 
 @enduml

lib-lua/themes/nominatim/init.lua

@@ -65,7 +65,19 @@ local table_definitions = {
             { column = 'geometry', type = 'geometry', projection = 'WGS84', not_null = true }
         },
         indexes = {}
-    }
+    },
+    place_postcode = {
+        ids = { type = 'any', id_column = 'osm_id', type_column = 'osm_type' },
+        columns = {
+            { column = 'postcode', type = 'text', not_null = true },
+            { column = 'country_code', type = 'text' },
+            { column = 'centroid', type = 'point', projection = 'WGS84', not_null = true },
+            { column = 'geometry', type = 'geometry', projection = 'WGS84' }
+        },
+        indexes = {
+            { column = 'postcode', method = 'btree' }
+        }
+     }
 }
 
 local insert_row = {}
@@ -113,6 +125,7 @@ local PlaceTransform = {}
 
 -- Special transform meanings which are interpreted elsewhere
 PlaceTransform.fallback = 'fallback'
+PlaceTransform.postcode_area = 'postcode_area'
 PlaceTransform.delete = 'delete'
 PlaceTransform.extra = 'extra'
 
@@ -419,11 +432,25 @@ function Place:write_place(k, v, mfunc)
     return 0
 end
 
-function Place:write_row(k, v)
+
+function Place:geometry_is_valid()
     if self.geometry == nil then
         self.geometry = self.geom_func(self.object)
+
+        if self.geometry == nil or self.geometry:is_null() then
+            self.geometry = false
+            return false
+        end
+
+        return true
     end
-    if self.geometry == nil or self.geometry:is_null() then
+
+    return self.geometry ~= false
+end
+
+
+function Place:write_row(k, v)
+    if not self:geometry_is_valid() then
         return 0
     end
 
@@ -675,30 +702,48 @@ function module.process_tags(o)
     if o.address.country ~= nil and #o.address.country ~= 2 then
         o.address['country'] = nil
     end
-    if POSTCODE_FALLBACK and fallback == nil and o.address.postcode ~= nil then
-        fallback = {'place', 'postcode', PlaceTransform.always}
-    end
 
     if o.address.interpolation ~= nil then
         o:write_place('place', 'houses', PlaceTransform.always)
         return
     end
 
     -- collect main keys
+    local postcode_collect = false
     for k, v in pairs(o.intags) do
         local ktable = MAIN_KEYS[k]
         if ktable then
             local ktype = ktable[v] or ktable[1]
             if type(ktype) == 'function' then
                 o:write_place(k, v, ktype)
+            elseif ktype == 'postcode_area' then
+                postcode_collect = true
+                if o.object.type == 'relation'
+                        and o.address.postcode ~= nil
+                        and o:geometry_is_valid() then
+                    insert_row.place_postcode{
+                        postcode = o.address.postcode,
+                        centroid = o.geometry:centroid(),
+                        geometry = o.geometry
+                    }
+                end
             elseif ktype == 'fallback' and o.has_name then
                 fallback = {k, v, PlaceTransform.named}
             end
         end
     end
 
-    if fallback ~= nil and o.num_entries == 0 then
-        o:write_place(fallback[1], fallback[2], fallback[3])
+    if o.num_entries == 0 then
+        if fallback ~= nil then
+            o:write_place(fallback[1], fallback[2], fallback[3])
+        elseif POSTCODE_FALLBACK and not postcode_collect
+                and o.address.postcode ~= nil
+                and o:geometry_is_valid() then
+            insert_row.place_postcode{
+                postcode = o.address.postcode,
+                centroid = o.geometry:centroid()
+            }
+        end
     end
 end
 

lib-lua/themes/nominatim/presets.lua

@@ -118,7 +118,7 @@ module.MAIN_TAGS.all_boundaries = {
                 place = 'delete',
                 land_area = 'delete',
                 protected_area = 'fallback',
-                postal_code = 'always'},
+                postal_code = 'postcode_area'},
     landuse = 'fallback',
     place = 'always'
 }

lib-sql/functions.sql

@@ -2,7 +2,7 @@
 --
 -- This file is part of Nominatim. (https://nominatim.org)
 --
--- Copyright (C) 2022 by the Nominatim developer community.
+-- Copyright (C) 2025 by the Nominatim developer community.
 -- For a full list of authors see the git log.
 
 {% include('functions/utils.sql') %}
@@ -18,7 +18,7 @@
     {% include 'functions/placex_triggers.sql' %}
 {% endif %}
 
-{% if 'location_postcode' in db.tables %}
+{% if 'location_postcodes' in db.tables %}
     {% include 'functions/postcode_triggers.sql' %}
 {% endif %}
 

lib-sql/functions/place_triggers.sql

@@ -2,7 +2,7 @@
 --
 -- This file is part of Nominatim. (https://nominatim.org)
 --
--- Copyright (C) 2022 by the Nominatim developer community.
+-- Copyright (C) 2025 by the Nominatim developer community.
 -- For a full list of authors see the git log.
 
 CREATE OR REPLACE FUNCTION place_insert()
@@ -89,35 +89,6 @@ BEGIN
     RETURN NEW;
   END IF;
 
-  -- ---- Postcode points.
-
-  IF NEW.class = 'place' AND NEW.type = 'postcode' THEN
-    -- Pure postcodes are never queried from placex so we don't add them.
-    -- location_postcodes is filled from the place table directly.
-
-    -- Remove any old placex entry.
-    DELETE FROM placex WHERE osm_type = NEW.osm_type and osm_id = NEW.osm_id;
-
-    IF existing.osm_type IS NOT NULL THEN
-      IF coalesce(existing.address, ''::hstore) != coalesce(NEW.address, ''::hstore)
-         OR existing.geometry::text != NEW.geometry::text
-      THEN
-        UPDATE place
-          SET name = NEW.name,
-              address = NEW.address,
-              extratags = NEW.extratags,
-              admin_level = NEW.admin_level,
-              geometry = NEW.geometry
-          WHERE osm_type = NEW.osm_type and osm_id = NEW.osm_id
-                and class = NEW.class and type = NEW.type;
-      END IF;
-
-      RETURN NULL;
-    END IF;
-
-    RETURN NEW;
-  END IF;
-
   -- ---- All other place types.
 
   -- When an area is changed from large to small: log and discard change
@@ -269,17 +240,6 @@ BEGIN
       WHERE osm_type = NEW.osm_type and osm_id = NEW.osm_id
             and class = NEW.class and type = NEW.type;
 
-    -- Postcode areas are only kept, when there is an actual postcode assigned.
-    IF NEW.class = 'boundary' AND NEW.type = 'postal_code' THEN
-      IF NEW.address is NULL OR NOT NEW.address ? 'postcode' THEN
-        -- postcode was deleted, no longer retain in placex
-        DELETE FROM placex where place_id = existingplacex.place_id;
-        RETURN NULL;
-      END IF;
-
-      NEW.name := hstore('ref', NEW.address->'postcode');
-    END IF;
-
     -- Boundaries must be areas.
     IF NEW.class in ('boundary')
        AND ST_GeometryType(NEW.geometry) not in ('ST_Polygon','ST_MultiPolygon')

lib-sql/functions/placex_triggers.sql

@@ -304,7 +304,6 @@ DECLARE
 BEGIN
   IF bnd.rank_search >= 26 or bnd.rank_address = 0
      or ST_GeometryType(bnd.geometry) NOT IN ('ST_Polygon','ST_MultiPolygon')
-     or bnd.type IN ('postcode', 'postal_code')
   THEN
     RETURN NULL;
   END IF;
@@ -359,8 +358,7 @@ BEGIN
 
   -- If extratags has a place tag, look for linked nodes by their place type.
   -- Area and node still have to have the same name.
-  IF bnd.extratags ? 'place' and bnd.extratags->'place' != 'postcode'
-     and bnd_name is not null
+  IF bnd.extratags ? 'place' and bnd_name is not null
   THEN
     FOR linked_placex IN
       SELECT * FROM placex
@@ -393,7 +391,6 @@ BEGIN
         AND placex.class = 'place'
         AND (placex.linked_place_id is null or placex.linked_place_id = bnd.place_id)
         AND placex.rank_search < 26 -- needed to select the right index
-        AND placex.type != 'postcode'
         AND ST_Covers(bnd.geometry, placex.geometry)
     LOOP
       {% if debug %}RAISE WARNING 'Found matching place node %', linked_placex.osm_id;{% endif %}
@@ -697,17 +694,7 @@ BEGIN
   ELSE
     is_area := ST_GeometryType(NEW.geometry) IN ('ST_Polygon','ST_MultiPolygon');
 
-    IF NEW.class in ('place','boundary')
-       AND NEW.type in ('postcode','postal_code')
-    THEN
-      IF NEW.address IS NULL OR NOT NEW.address ? 'postcode' THEN
-          -- most likely just a part of a multipolygon postcode boundary, throw it away
-          RETURN NULL;
-      END IF;
-
-      NEW.name := hstore('ref', NEW.address->'postcode');
-
-    ELSEIF NEW.class = 'highway' AND is_area AND NEW.name is null
+    IF NEW.class = 'highway' AND is_area AND NEW.name is null
            AND NEW.extratags ? 'area' AND NEW.extratags->'area' = 'yes'
     THEN
         RETURN NULL;
@@ -877,16 +864,6 @@ BEGIN
           and (linked_place is null or place_id != linked_place);
   -- update not necessary for osmline, cause linked_place_id does not exist
 
-  -- Postcodes are just here to compute the centroids. They are not searchable
-  -- unless they are a boundary=postal_code.
-  -- There was an error in the style so that boundary=postal_code used to be
-  -- imported as place=postcode. That's why relations are allowed to pass here.
-  -- This can go away in a couple of versions.
-  IF NEW.class = 'place'  and NEW.type = 'postcode' and NEW.osm_type != 'R' THEN
-    NEW.token_info := null;
-    RETURN NEW;
-  END IF;
-
   -- Compute a preliminary centroid.
   NEW.centroid := get_center_point(NEW.geometry);
 
@@ -1286,8 +1263,6 @@ BEGIN
     END IF;
   ELSEIF NEW.rank_address > 25 THEN
     max_rank := 25;
-  ELSEIF NEW.class in ('place','boundary') and NEW.type in ('postcode','postal_code') THEN
-    max_rank := NEW.rank_search;
   ELSE
     max_rank := NEW.rank_address;
   END IF;
@@ -1424,7 +1399,7 @@ BEGIN
 
   {% if debug %}RAISE WARNING 'placex_delete:12 % %',OLD.osm_type,OLD.osm_id;{% endif %}
 
-  UPDATE location_postcode SET indexed_status = 2 WHERE parent_place_id = OLD.place_id;
+  UPDATE location_postcodes SET indexed_status = 2 WHERE parent_place_id = OLD.place_id;
 
   RETURN OLD;