trackdb_open(TRACKDB_NO_UPGRADE|TRACKDB_READ_ONLY);
global_tid = trackdb_begin_transaction();
if((err = trackdb_get_global_tid("required-tags", global_tid, &tags)))
trackdb_open(TRACKDB_NO_UPGRADE|TRACKDB_READ_ONLY);
global_tid = trackdb_begin_transaction();
if((err = trackdb_get_global_tid("required-tags", global_tid, &tags)))