Authorised by Academic Registrar, April 1996
Objectives At the completion of this subject students should understand the fact-based approach to information modelling and be able to use it successfully in a variety of situations; understand how to transform fact-based information models to relational models and be able to perform this transformation successfully; and understand the differences between the entity relationship approach and the fact-based approach to information modelling.
Synopsis Information systems and the conceptual schema. Conceptual, external and internal levels. The fact-based approach to information modelling. Specifying fact types and adding constraints such as uniqueness, mandatory roles, values, subtyping, occurrence frequencies, subset, equality, exclusion, logical and user-defined constraints. Derivation rules. The relational model of data. Domains, attributes, relations, candidate, primary and foreign keys. Entity, referential and user-defined integrity. Mapping fact-based conceptual schemas to relational schemas with particular emphasis on constraint implementation through database triggers, rules and procedures. Equivalence transformations on conceptual schemas and optimisation strategies. Comparison of fact-based models to entity relationship models.
Assessment Examination (3 hours): 50% + Practical work: 50%