For my understanding can we take backup the catalog database through RMAN


1. yes possible to take backup like

rman target / catalog catalogdbusername/password@catalogdbname

How ever it wont be good to have backup like this better to go with offline
usermanged backup

(or)

2. just say rman and then target as your catalog database and take backup but
still it wont be advisable as there is no use of it too

Regards

Rajesh RD