Use show_role to display the currently active system roles for the specified login:
show_role()
If you have not activated any system role, show_role returns NULL. If you are a database owner, and you execute show_role after using setuser to impersonate another user, show_role returns your own active system roles, not those for whom you are impersonating.
Any user can execute show_role.
The show_role function does
not include information about user-defined roles.
