DBMS REFRESH

• Destroy

DBMS_REFRESH.DESTROY (
  name   IN   VARCHAR2);

BEGIN
DBMS_REFRESH.DESTROY (
  name   =>   'DVAG_REFRESH_GROUP');
commit;
END;
/

• Subtract

DBMS_REFRESH.SUBTRACT (
  name      IN    VARCHAR2,
  { list    IN    VARCHAR2,
  | tab     IN    DBMS_UTILITY.UNCL_ARRAY, }
  lax       IN    BOOLEAN := false);

BEGIN
DBMS_REFRESH.SUBTRACT (
  name      =>    'DVAG_REFRESH_GROUP',
  list      =>    'SNAP$_WORKFLOWS');
commit;
END;
/

Reference:

• http://docs.oracle.com/cd/B28359_01/server.111/b28327/rarrefreshpac.htm#i94210