text: ---------------------------------------------------------------
  -- table: os_wards.  indexes and geometry
  ---------------------------------------------------------------
  
  -- geometry: set srid.
  select updategeometrysrid('os_wards', 'geom', 27700);
  
  -- index: cuix_wards_code.  a unique clustered index on the ward code.
  create unique index cuix_wards_code_name on os_wards using btree (code, name);
  alter table os_wards cluster on cuix_wards_code_name;
  
  -- Index: ix_wards_geom.  a spatial index on the geometry.
  create index ix_wards_geom on os_wards using gist (geom);