GV$FLASHBACK_DATABASE_STAT

select
inst_id,                 -- INST_ID NUMBER
to_date                  -- BEGIN_TIME DATE
  (btime, 'MM/DD/RR HH24:MI:SS', 'NLS_CALENDAR=Gregorian'),
to_date                  -- END_TIME DATE
  (etime, 'MM/DD/RR HH24:MI:SS', 'NLS_CALENDAR=Gregorian'),
fbw*512,                 -- FLASHBACK_DATA NUMBER
dbw*512,                 -- DB_DATA NUMBER
redow*512,               -- REDO_DATA NUMBER
to_number (fbsz)         -- ESTIMATED_FLASHBACK_SIZE NUMBER
from
x$krfgstat
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