The Use of a Metadata Repository in Spatial Database Development

Database schemas currently used to define spatial databases are deficient in that they do not incorporate facilities to specify business rules/integrity constraints. This shortcoming has been noted by GŸnther and Lamberts [GŸnther & Lamberts, 1994] who commented that geographical information systems (GIS) do not generally offer any functionality to preserve semantic integrity. It is desirable that this functionality be incorporated for reasons of consistency and so that an estimate of the accuracy of data entry can be made. Research into constraints upon spatial relationships at the conceptual level is well documented. A number of researchers have shown that the transition from conceptual to logical spatial data models is possible [Firns, 1994; Hadzilacos & Tryfona, 1995]. The algorithmic accomplishment of this transition is a subject of current research. This paper presents one approach to incorporating spatial business rules in spatially referenced database schemas by means of a repository. It is demonstrated that the repository has an important role to play in spatial data management and in particular automatic schema generation for spatially referenced databases. 1 Address correspondence to: Ms S.K.S. Cockcroft, Asst Lecturer, Department of Information Science, University of Otago, P.O. Box 56, Dunedin, New Zealand. Fax: +64 3 479 8311 Email: [email protected] 2 User or business rules are a superset of integrity constraints. They include domains and triggering operations as well as entity integrity and referential integrity constraints. 3 A place where design information may be stored, retrieved and manipulated by design tools.