INTENT ANALYSERS AND MODES OF ASSOCIATION IN RELATIONAL DATA BASES

Abstract

A mode of association is a set of propositions about a given association between relations. It is schema-defined and permits the capture of the precise meaning of an association. Modes of association may be used with the relational language SQL/N, an upward compatible extension to SQL. They permit concise SQL/N expressions even when quite complex associations are involved, and allow the use of the entire range of natural quantifiers with all types of association. Because modes of association permit the user to operate at a higher level of abstraction than with SQL, subtle errors of intent are more likely. An intent analyser can be used to detect such errors in SQL/N expressions. Some intent analyser procedures are described.