Spatial Data Integrity Constraints in Object Oriented Geographic Data Modeling

An important activity in the design of a particular database appli-cation consists in identifying the integrity constraints that must hold on the database, and that are used to detect and evaluate in-consistencies. It is possible to improve data quality by imposing constraints upon data entered into the database. These constraints must be identified and recorded at the database design level. However, it is clear that modeling geographic data requires mod-els which are more specific and capable of capturing the seman-tics of geographic data. Within a geographic context, topological relations and other spatial relationships are fundamentally impor-tant in the definition of spatial integrity rules. This paper dis-cusses the relationship that exists between the nature of spatial information, spatial relationships, and spatial integrity constraints, and proposes the use of OMT-G, an extension of the OMT model for geographic applications, at an early stage in the specification of integrity constraints in spatial databases. OMT-G provides ade-quate primitives for representing spatial data, supports spatial re-lationships, and allows topological, semantic and user integrity rules to be specified in the database schema