These two statements both revoke permission for all users except the table owner to update the price and total_sales columns of the titles table:
revoke update on titles (price, total_sales) from public
This statement revokes permission from Clare to update the authors table, and simultaneously revokes that permission from all users to whom she had granted that permission:
revoke update on authors from clare cascade
This statement revokes permission from operators to execute the custom stored procedure new_sproc:
revoke execute on new_sproc from oper_role
