Yes. Datalog is not Turing-complete; thus is much easier to reason about, and good query optimizers can be much more aggressive. Once you introduce cuts (as in

Yes. Datalog is not Turing-complete; thus is much easier to reason about, and good query optimizers can be much more aggressive. Once you introduce cuts (as in prolog), you have to throw a lot of that out the window. But Datalog is a subset of prolog.