Update Policies

Underspecified transactions can be supported in databases by enabling administrators to specify update policies that complete underspecified transactions. We propose a language for expressing such update policies. We show that the problem of verifying whether or not a policy is sound and complete with respect to database constraints is undecidable in general. We identify decidable instances of this decision problem, and for such instances, present an algorithm that uses resolution to check whether or not a supplied policy is sound and complete with respect to database constraints.