Higher Order Datalog

The research of the last years on the definition of a logic language for databases, has mostly focused on DATALOG (Ceri '89), a logic language based on Horn clauses without functional symbols. In this paper we present a higher order form of DATALOG, called DATALOG-II, based on a second order logic programmic language, which appears to be an interesting rich language in its own right. We also make consideration between higher order and metalevel logic programming approaches and we give a kind of implementation of DATALOG-II in a metalevel logic programming languages with a well defined complete semantic, that we use to understand the obtained implementation and from that define the semantic of DATALOG-II