We have developed a system to process database queries over composed data providing web services. The queries are transformed into execution plans containing an operator that invok...
Queries involving aggregation are typical in a number of database research areas, such as data warehousing, global information systems and mobile computing. One of the main ideas ...
In Deep Web data integration, some Web database interfaces express exclusive predicates of the form Qe = Pi(Pi ∈ P1, P2, . . . , Pm), which permits only one predicate to be selec...
Deep web search requires a transformation between search keywords and semantically described and well-formed data structures. We approached this problem in our "In the Web of ...
The class of unions of conjunctive queries (UCQ) has been shown to be particularly well-behaved for data exchange; its certain answers can be computed in polynomial time (in terms...