“…3.5.3 above. Here, a query q can be evaluated against an integrated set of data D sources to produce a result r, where the integration arises from a set of mappings v over the mediated model m obtained from D. In a globalas-view approach [28], the query q posed against the mediated schema arising from the integration of D is translated using the mapping elements in v over m into single-source queries (see [28] for a survey of the techniques involved). Thus, if D = {d 1 , d 2 }, then, broadly speaking, two operations are issued, viz., r 1 := evalQ(d 1 , q 1 ) and r 2 := evalQ(d 2 , q 2 ) using v over m to derive both q 1 and q 2 from q, and, on the way back, r from r 1 and r 2 .…”