The simple spy database does the job, but it is incomplete. Any self-respecting spymaster would keep the following information on each agent:
Specialty (each spy could have several specialties)
It might be tempting to build a slightly bigger table to hold this information. Figure 11.27 illustrates such a table.
When you carefully analyze this version of the spy database, you’ll notice a couple of problems that crop up frequently in real databases. First, ...