Jul 23 2010
Domain Integrity in Relational Database
A domain is the set of all possible values for a given attribute. A domain integrity constraint—usually just called a domain constraint—is a rule that defines these legal values. It might, of course, be necessary to define more than one domain constraint to describe a domain completely. A domain isn’t the same thing as a [...]
Jul 21 2010
Creating Data Integrity
Creating a model of the entities in the problem space and the relationships between them is only part of the data modeling process. You must also capture the rules that the database system will use to ensure that the actual physical data stored in it is, if not correct, at least plausible. In other words, [...]