Internal Integration Level

At the middle level, the system has an internal integration engine, which is based on computational logic and deductive database technology, i.e. the DLV System. In particular, recent research results on information integration indicate that the reformulation process at the Information Service Level may yield a query which can be suitably expressed in terms of disjunctive Datalog. Thus, at this level, the system takes as input the result of the reformulation process carried out at the higher level, devises a query plan in terms of a disjunctive Datalog program, and execute it by applying suitable optimization strategies.

Data Acquisition and Trasformation Level ->