Path-Functional Dependencies and the Two-Variable Guarded Fragment with Counting

Abstract

We examine how logical reasoning in the two-variable guarded fragment with counting quantifiers can be integrated with databases in the presence of certain integrity constraints, called path-functional dependencies. In more detail, we establish that the problems of satisfiability and finite satisfiability for the two-variable guarded fragment with counting quantifiers, a database, and binary path-functional dependencies are EXPTIME-complete; we also establish that the data complexity of these problems is NP-complete. We establish that query answering for the above fragment (with a database and binary path-functional dependencies) is 2-EXPTIME-complete with respect to arbitrary models, and provide a 2-EXPTIME upper bound for finite models. Finally, we establish that the data complexity of query answering is coNP-complete, both with respect to arbitrary and finite models.

Date of Award	1 Aug 2017
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Ian Pratt-Hartmann (Supervisor) & Renate Schmidt (Supervisor)