GV$RMAN_COMPRESSION_ALGORITHM definition in Oracle Database 11.2
GV$RMAN_COMPRESSION_ALGORITHM

SELECT
  inst_id,                                 -- INST_ID NUMBER
  algname_krbmca,                          -- ALGORITHM_NAME VARCHAR2(64)
  decode(                                  -- INITIAL_RELEASE VARCHAR2(18)
    lowvsn_krbmca, '', NULL, lowvsn_krbmca),
  decode(                                  -- TERMINAL_RELEASE VARCHAR2(18)
    highvsn_krbmca, '', NULL, highvsn_krbmca),
  algdesc_krbmca,                          -- ALGORITHM_DESCRIPTION VARCHAR2(64)
  algvsn_krbmca,                           -- ALGORITHM_COMPATIBILITY VARCHAR2(18)
  DECODE(                                  -- IS_VALID VARCHAR2(3)
    isvalid_krbmca, 0, 'NO', 'YES'),
  DECODE(                                  -- REQUIRES_ACO VARCHAR2(3)
    bitand(flags_krbmca, 1), 0, 'NO', 'YES') 
FROM
  x$krbmca
WHERE
  bitand(flags_krbmca, 2) = 0

home |  up