ok....this is what's going on.

from unix:
1. sqlplus
2. username/password
3. sqlplus> SET ROLE role_name;
4. sqlplus> role set.
5. sqlplus> host sqlldr
6. but when you are in sqlldr they ask for username and password again. once I type username and password again, Is my role still set or not? If I type in username/password again inside the sqlldr, am I in same session as sqlplus or not?