The pseudo-code might be considered rather complex for such a simple query. It can be considerably simplified by adding a `redundant' direct relationship type from CUS to CUS_PAYMENT. A foreign key (the customer's account number) would be placed in CUS_PAYMENT as an extra attribute. While unnecessary, as we have said, this relationship type is advantageous in that the pseudo-code for the query is now as shown in Fig. 3.20, which is much simpler.