A Temporal and Probabilistic, Deductive and Object-Oriented Query Language.
Beat Wüthrich, Weiguang Tong, Krishnaswamy Sankaran · 1995
Novel concepts are presented to enhance query languages to represent time and uncertainty. We specifically enhance FQL , a deductive and object-oriented query language, with the abilities to adequately represent time and uncertainty. 1 Introduction Any piece of data can additionally be specified along two dimensions: ffl time, and ffl uncertainty. These two specifications are independent of the way the data is represented. For example, suppose it is given that a customer C will buy some portion of a mutual fund F . In whatever form this is represented, (i) either as the tuple (C; F ) in a relational table with name Buy, (ii) as a fact buy(C; F ), or (iii) in functional form as a function Buy mapping the customer C to the value F , two pieces of information can additionally be provided: ffl when customer C will buy some portions of fund F , and ffl how certain it is that C bought or will buy portions of fund F . Many sophisticated methods to handle time in databases have been ...