+
+
+@_migration(4, 2, 99, 0)
+def enable_forward_dependencies(conn: Connection, **_: Any) -> None:
+ """ Create indexes for updates with forward dependency tracking (long-running).
+ """
+ if conn.table_exists('planet_osm_ways'):
+ with conn.cursor() as cur:
+ cur.execute("""SELECT * FROM pg_indexes
+ WHERE tablename = 'planet_osm_ways'
+ and indexdef LIKE '%nodes%'""")
+ if cur.rowcount == 0:
+ cur.execute("""CREATE OR REPLACE FUNCTION public.planet_osm_index_bucket(bigint[])
+ RETURNS bigint[]
+ LANGUAGE sql IMMUTABLE
+ AS $function$
+ SELECT ARRAY(SELECT DISTINCT unnest($1) >> 5)
+ $function$""")
+ cur.execute("""CREATE INDEX planet_osm_ways_nodes_bucket_idx
+ ON planet_osm_ways
+ USING gin (planet_osm_index_bucket(nodes))
+ WITH (fastupdate=off)""")
+ cur.execute("""CREATE INDEX planet_osm_rels_parts_idx
+ ON planet_osm_rels USING gin (parts)
+ WITH (fastupdate=off)""")
+ cur.execute("ANALYZE planet_osm_ways")