ABSTRACT
A formal meta-model, exploited to define the conceptual model of a database design method named “ASSO,” is proposed. The approach integrates features from methodologies of conceptual database design with the formal method B. Starting from a conceptual model based on the notions of class and is-a relationship, two gradual model extensions are considered: the former defines the basic operations, whereas the latter defines the ASSO model, called “Structured Database Schema.” The Structured Database Schema permits large conceptual Schemas to be specified in terms of class and specialized class and large consistency proofs to be reduced to small consistency proofs. The Structured Database Schema “goodness” is guaranteed by proposing model extensions compatible with the previous models. Both a “qualitative measure” of information implicitly specified within the Structured Database Schema and a “qualitative evaluation” of the consistency costs are provided.
