9901877<br/>Chomicki<br/><br/>This Americas Program award will fund a two year cooperative research project between Dr. Jan Chomicki, Monmouth College, NJ, and Dr. Leopoldo Bertossi, Pontificia Universidad Catolica de Chile, on a project to search for a logical characterization of consistent query answers in relational databases that may be inconsistent with the given integrity constraints. Integrity constraints capture an important normative aspect of every database application, but often their satisfaction cannot be guaranteed and there may exist database instances that violate them. It is important to know which query answers are consistent with the integrity constraints, and which are not. To answer this question the research will address a number of issues, including semantics of consistent query answers, procedures to compute consistent query answers and their implementation, formal analysis of the properties of such procedures, soundness, completeness, termination, computations, complexity, identification of classes of constraints with superior computational properties, and applications to data cleaning in data warehouses, information integration in heterogeneous databases, and triggers Results of this study could be applied to a number of areas, including data warehousing (CD97), database integration and active and reactive databases. <br/><br/>This cooperative project brings together Dr. Chomicki's expertise in database theory with Dr. Bertossi's extensive background in mathematical logic and knowledge presentation. This combination will greatly enhance the opportunity for a successful solution to the issues addressed by this study .