A query is satisfiable if there is at least one consistent instance of the database in which it has a non-empty answer. Defining queries on a database schema and checking their satisfiability can help the database designer to be sure whether the produced database schema is what was intended. The formulation of such queries may easily require the use of some arithmetic comparisons or negated expressions. Unfortunately, checking the satisfiability of this class of queries on a database schema that most likely have some
integrity constraints (e.g., keys, foreign keys, Boolean checks) is, in general, undecidable.
However, although the problem is undecidable for such a class of schemas and queries, it
may not be so for a particular query satisfiability check. In this paper, we propose to perform a termination test as a previous step to query satisfiability checking. If positive, the termination test guarantees that the corresponding query satisfiability check will terminate. We assume the CQC method is the underlying query satisfiability checking method; to the best of our knowledge, it is the only method of this kind able to deal with schemas and queries as expressive as the ones we consider.
All rights reserved. This work is protected by the corresponding intellectual and industrial property rights. Without prejudice to any existing legal exemptions, reproduction, distribution, public communication or transformation of this work are prohibited without permission of the copyright holder. If you wish to make any use of the work not provided for in the law, please contact: firstname.lastname@example.org