Author_Institution :
Ist. di Analisi dei Sistemi ed Informatica, Consiglio Nazionale delle Ricerche, Rome, Italy
Abstract :
Checking satisfiability of database constraints is a fundamental problem in database design. In addition, database constraints have to be not only satisfiable but also finitely satisfiable. This problem is generally addressed by using theorem provers that, being developed for first order logic formulas, are based on semidecidable procedures. Furthermore, even in simple cases, theorem provers are quite inefficient in dealing with comparison operators such as, for instance, the equality. In this paper, a decidable, sound, and complete method for checking finite satisfiability of a specific class of integrity constraints for object-oriented databases, including the equality constraints, is presented. The method, that is based on a graph-theoretic approach, has exponential complexity in the worst case, rarely occurring in practice