7.5. Final Checks

The conceptual schema design procedure facilitates early detection of errors by various checks, including communication with the user by way of examples. Four final checks may also be performed to help detect any errors that might have slipped through. These are designed to ensure internal consistency, external consistency, lack of redundancy, and completeness. We now consider these in order.

A conceptual schema is internally consistent if and only if each role sequence used as a predicate or constraint argument can be populated in some state. This topic was discussed in the previous chapter, where it was called “population consistency” or “strong satisfiability”. Basically it means that the specified constraints do not contradict ...

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