Safety of recursive Horn clauses with infinite relations
Raghu Ramakrishnan, François Bancilhon, Abraham Silberschatz · 1987
A database query is said to be safe if its result consists of a finite set of tuples If a query is expressed using a set of pure Horn Clauses, the problem of determining whether it is safe is in general undecidable In this paper, we show that the problem is decidable when terms involving function symbols (including arithmetic) are represented as distinct occurrences of uninterpreted infinite predicates over which certain finiteness dependencies hold. We present a sufficient condition for safety when some monotonicity constraints also hold.