Numerical Queries in Incomplete Information Data Bases
Michał Jaegermann, Witold J. Lipski · Fundamenta Informaticae · 1983
We consider the problem of answering numerical queries, i.e. queries involving cardinalities of sets of objects with specified conditions, in a data base where information is incomplete. We give an algorithm to compute a lower bound and an upper bound on the response to a numerical query. The bounds proceduced by the algorithm are the best logically derivable from the information available in the data base.