ORA-00038: Cannot create session: server group
belongs to another user
Cause: An attempt was made to create a non-migratable session in a
server group that is owned by a different user.
Action: A server group is owned by the first user who logs into a server
in the server group in non-migratable mode. All subsequent non-migratable mode
logins must be made by the user who owns the server group. To have a different
user login in non-migratable mode, the ownership of the server group will have
to be changed. This can be done by logging off all current sessions and
detaching from all existing servers in the server group and then having the new
user login to become the new owner.