Abstract
We study the notion of boundedness in the context
of positive existential rules, that is, whether there
exists an upper bound to the depth of the chase procedure, that is independent from the initial instance.
By focussing our attention on the oblivious and the
semi-oblivious chase variants, we give a characterization of boundedness in terms of FO-rewritability
and chase termination. We show that it is decidable
to recognize if a set of rules is bounded for several
classes and outline the complexity of the problem