Semantic integrity in a relational data base system
Michael M. Hammer, Dennis J. McLeod · 1975
As a model of some aspect(s) of the real world, the data in a data base must be accurate. In the context of a relational data base system, a facility to allow the expression and enforcement of a set of semantic integrity constraints is discussed. Semantic integrity constraints may describe properties of and relationships between data objects (in a relational data base) that are to hold (state snapshot constraints). Constraints may also place limitations on permissible data base operations (state transition constraints).