reindex postcodes that loose their parents

When the parent place of a postcode is deleted, it needs to
be reindexed to get a new parent. Otherwise displaying of
results is broken.

lib-sql/functions/placex_triggers.sql

@@ -1399,6 +1399,8 @@ 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;
+
   RETURN OLD;
 
 END;

lib-sql/indices.sql

@@ -81,6 +81,9 @@ CREATE INDEX IF NOT EXISTS idx_postcode_postcode
     type TEXT,
     deferred BOOLEAN
    );
+---
+  CREATE INDEX IF NOT EXISTS idx_location_postcode_parent_place_id
+    ON location_postcode USING BTREE (parent_place_id) {{db.tablespace.address_index}};
 {% endif %}
 
 -- Indices only needed for search.