2015/05/10 by Filip Mazowiecki, Mazowiecki, Filip, Joanna Ochremiak +3
Computer Science · #Databases (cs.DB) #FOS: Computer and information sciences #Logic in Computer Science (cs.LO) #cs.DB #cs.LO
paper · pdf · doi:10.48550/arxiv.1505.02444
arxiv created 2015/05/10 · arxiv updated 2015/05/12
We study the problem of eliminating recursion from monadic datalog programs on trees with an infinite set of labels. We show that the boundedness problem, i.e., determining whether a datalog program is equivalent to some nonrecursive one is undecidable but the decidability is regained if the descendant relation is disallowed. Under similar restrictions we obtain decidability of the problem of equivalence to a given nonrecursive program. We investigate the connection between these two problems in more detail.