B.N. Rossiter
M.A. Heather
University of Newcastle upon Tyne. 1992
The subject of databases is both theoretical and very practical but theory has hardly kept pace with the demand-driven momentum of practical applications. In particular, demands for database systems to handle complex object structures and behaviour of objects gives the obvious dangers that many ad hoc solutions will be adopted which lack a theoretical basis and suffer from limited information on their applicability and predictability in operation. The power of databases is to operate across many levels coherently from the conceptual schema right across to the bit address on the physical storage medium. However, at the time database theory was developing, it was necessary to customise notation from set theory to represent transformations of common data structures at an abstract level. Standard database texts indicate a need for the use of higher level abstract formalism. This report considers the use of category theory for data modelling with the more traditional set-theoretic approach applied directly or by means of the representation language Z.