Â“Spatial databasesÂ” consist of large groups of data structured in a way to represent the geographic features of interest to the users of a system. Spatial database models are schematic representations of these data. Database models are created to design and document the system, to facilitate communication and to support programming. They are created using CASE tools (computer-assisted software engineering). CASE tools support schema drawing, dictionaries and code generation. Database schemas are typically represented with a graphical language such as UML (Unified Modeling Language; see http://www.uml.org and ).
Â“Database modelsÂ” can represent (1) users’ real-life views of the data of interest, (2) developers’ views of the potential organization of these data for a family of technologies, or (3) their final implementation on a specific platform. For example, in the standard Model-Driven Architecture (MDA) method (http://www.omg.org/mda/), these three models represent three levels of abstraction and are respectively called CIM (computation-independent model), PIM (platform-independent model) and PSM (platform-specific model). In other methods, they may be called conceptual, logical and physical models as well as analysis, design and implementation models.