A complete universal query operator.
Richard Elling Moe · 2007
We argue that the division operator in relational algebra is insufficiently equipped to handle all kinds of universal queries. This is a problem since division is widely regarded as the operational counterpart of universal quantification. Accordingly, research related to universal queries, for instance on query-optimization, is based on division. We propose generalized division operators to provide better approximations of the concept of universal quantification. 1