F.22. old_snapshot
The old_snapshot module allows inspection of the server state that is used to implement old_snapshot_threshold.
F.22.1. Functions
pg_old_snapshot_time_mapping(array_offset OUT int4, end_timestamp OUT timestamptz, newest_xmin OUT xid) returns setof recordReturns 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.