Information Modeling and Relational Databases, 2nd Edition

4.1. Introduction to CSDP Step 4

So far, the conceptual schema design procedure has focused on specifying the elementary fact types, both asserted and derived. The rest of the CSDP is concerned mostly with specifying constraints. Constraints apply to the database and are either static or dynamic. Static constraints apply to each individual state of the database and may usually be specified on a schema diagram, as discussed in CSDP steps 4-7. Examples include uniqueness, mandatory role, set comparison, value, subtyping, frequency, and ring constraints. Dynamic constraints restrict transitions between states, are often expressed in other ways (e.g., state charts), and are considered in step 7, along with other constraints. In practice, we usually ...