On the family of generalized dependency constraints

Abstract

A common framework is provided for the investigation of various types of integnty constraints for relaaonal databases. The family of generahzed dependency constraints is introduced. It is shown that this famdy contains as members most of the classes of dependencies studied m the database literature as well as some other classes of database constraints. A charactenzaaon, together with an algorithm, Is provided for determining whether or not a universal statement of first-order logic is a logical consequence of a class in the family. Thts result is shown to be a generalization of former results concerning unphcatmns of dependencies and yields a connection between the resolution method and the chase method as well as a method for constructing Armstrong databases In addition, an alternative version of the theorem ~s described, the preservation of the theorem is discussed m the context of lossless join decomposluons, and the extension of the results to embedded dependencies is elaborated.