
object types should be replaced by nested object types. If the original database involved
views, you need to make any needed adjustments to prevent the reverse-engineered
constructs leading to base tables when the schema is forward engineered.
Once the semantics of the as-is database schema have been clarified, you should
look to see if some additional constraints need to be added to provide a more complete
to-be model. As a trivial example, the value constraint {1..5} has been added to
CertificationLevel in Figure 8–13.
Often, you may find that the database was badly designed in the first place, with
problems such as uncontrolled denormalization and ...