old_snapshot — inspect <literal>old_snapshot_threshold</literal> state old_snapshot The old_snapshot module allows inspection of the server state that is used to implement . Functions pg_old_snapshot_time_mapping(array_offset OUT int4, end_timestamp OUT timestamptz, newest_xmin OUT xid) returns setof record Returns all of the entries in the server's timestamp to XID mapping. Each entry represents the newest xmin of any snapshot taken in the corresponding minute.