Existential active integrity constraints

Active integrity constraints (AICs) are a useful formalism to express integrity constraints and policies to restore consistency in databases violating them. However, AICs do not allow users to express different kinds of constraints commonly arising in practice, such as foreign keys. In this paper, we propose existential active integrity constraints (EAICs), a powerful extension of AICs that allows us to express a wide range of constraints used in databases and ontological systems. We investigate different properties of EAICs. Specifically, we show that there exists a "representative" set of founded updates, called universal, which suffices for query answering. As such a set might contain an infinite number of founded updates, each of infinite size, we study syntactic restrictions ensuring finiteness, as well as the existence of a single universal founded update.