A calculus for complex objects
The restrictions of the first normal form in constructing data models and the attempts to overgo them are explained. A new data model, similar to Kuper and Vardi's model [\textit{G. M. Kuper} and \textit{M. Y. Vardi}, A new approach to database logic, in ``Proceedings ACM Symposium on Principles of Database Systems, Waterloo, April 1984,'' pp. 86-96. \textit{G. M. Kuper} and \textit{M. Y. Vardi}, On expressive power of the logic data model, SIGMOD 1985, Austin, Texas, pp. 180-187], but with a not structured database is proposed. Structure is imposed on the set of complex objects through the subobject relation. In result the set of objects together with the subject relationship forms a lattice. The calculus is defined and the Horn classes are extended to the case of complex objects. In section 2 the complex objects of the model are defined and the semantics of object equality is given. in Section 3 the subobject relationship is defined and how it introduces a lattice structure is shown. In Section 4 the complex objects calculus is defined and in Section 5 conclusions and directions for future research are presented. The examples on database records forms are given. 12 Definitions are given, 5 Theorems and 1 Lemma are proved. Sorry, but Definition 3.3 does not exist. Bibliography 14 items.
scientific article; zbMATH DE number 4108201