Adding secondary groups and running processes

Assuming a Unix-like Operating System, running processes will not pick up the new secondary group. To pick up the new group membership a new login will be required. If you are starting / stopping Oracle as root via scripts, that is probably sufficient. If you are logged in as the Oracle user, then you will have to log out and back in again.

In general, Unix-like operating systems assign users to groups at login time. You can see this using the id -a command which will show all group membership. Run id -a, then add yourself to additional groups and run id -a again. The new groups will NOT show up. Log out and back in and run id -a and the new groups will show up.