The authors present a system that computes for a query that may be incomplete, complete approximations from above and from below. They assume a setting where queries are posed over a partially complete database, that is, a database that is generally incomplete, but is known to contain complete information about specific aspects of its application ...

The authors demonstrate a full-edged implementation of first-class functions for the widely used PL/SQL database programming language. Functions are treated as regular data items that may be constructed at query runtime, stored in and retrieved from tables, assigned to variables and passed to and from other (higher-order) functions. The resulting PL/SQL dialect concisely and elegantly ...

Today’s, information systems are complex systems that have to deal with a variety of different and potentially conflicting needs. Capturing their strategic requirements is a critical activity, as it must answer at the same time to software and corporate goals. In this paper, the authors introduce the economic foundations of strategic requirements. They propose a ...