select
  OLDEST_FLASHBACK_SCN,                    -- OLDEST_FLASHBACK_SCN NUMBER
  OLDEST_FLASHBACK_TIME,                   -- OLDEST_FLASHBACK_TIME DATE
  RETENTION_TARGET,                        -- RETENTION_TARGET NUMBER
  FLASHBACK_SIZE,                          -- FLASHBACK_SIZE NUMBER
  ESTIMATED_FLASHBACK_SIZE                 -- ESTIMATED_FLASHBACK_SIZE NUMBER
from
  GV$FLASHBACK_DATABASE_LOG
where
  inst_id = USERENV('Instance')