Which is the correct way to connect to both the target database and the recovery catalog
from the RMAN command line? Assume that the target database is called ORCL and that the
recovery catalog database is called RCAT. Also assume that the recovery-catalog owner is called
RCAT_OWN. Assume the environment is configured for the ORCL database. (Choose all that
apply.)
A. rman target=/ catalog=/@rcat
B. rman target=/ catalog=rcat_own/rcat_own
C. rman target=/ catalog=rcat_own/rcat_own@RCAT
D. rman target=sys/robert@orcl catalog=rcat_own/rcat_own@RCAT
E. You cannot connect to the target database and the recovery catalog at the same time.
Option C connects to the database locally,while option D connects through Oracle Net.Both methods are completely legal.
原文：http://www.cnblogs.com/Babylon/p/7814150.html