select
  inst_id,                                 -- INST_ID NUMBER
  to_number(fblogscn),                     -- OLDEST_FLASHBACK_SCN NUMBER
  to_date(                                 -- OLDEST_FLASHBACK_TIME DATE
    fblogtim, 'MM/DD/RR HH24:MI:SS','NLS_CALENDAR=Gregorian'),
  fblogretn,                               -- RETENTION_TARGET NUMBER
  totsize,                                 -- FLASHBACK_SIZE NUMBER
  to_number(fblogesiz)                     -- ESTIMATED_FLASHBACK_SIZE NUMBER
from
  x$krfblog,
  (
  select
    sum(flebsz * flenblks) totsize
  from
    x$kccfle
  where
    fledup != 0 )