Information Modeling and Relational Databases, 2nd Edition

5.1. Introduction to CSDP Step 5

So far you’ve learned how to proceed from familiar information examples to a conceptual schema diagram in which the elementary fact types are clearly set out, with the relevant uniqueness constraints marked on each. You also learned how to perform some checks on the quality of the schemas. In practice, other kinds of constraints and checks need to be considered also.

Next in importance to uniqueness constraints are mandatory role constraints.Basically these indicate which roles must be played by the population of an object type and which are optional. Once mandatory role constraints are specified, a check is made to see if some fact types may be logically derived from others. This constitutes the next step in ...