The support from CTI ended in April 1997. Since then, the project mainly relies on workforce from UNIL and EPFL S Database lab, with occasional discussions with the other partners as appropriate. Moreover the data models supported by the major GIS are poor logical models, based on the relational model, with geographic concepts reflecting their internal implementation techniques, and without any support for the time dimension. Derivation through aggregations is frequent. Refinement is used to constrain the domain in the subtype to be a subdomain of the corresponding property in the supertype.
New icons allow to visually define the spatio-temporal characteristics of the data.
In all these applications, spatial entites like cities, roads, counties, rivers, etc., are perceived. Thanks to the orthogonality of the model, spatiality may be associated to object types, attributes, relationships, and aggregations. Being a flexible model, MADS allows to describe a spatial feature either as an object or as an attribute, according to the abstraction level considered by the application. A spatial object type has a predefined attribute, geometry, whose domain of values is a spatial abstract type. MADS also seamlessly integrates the continuous view of space by supporting the concept of space-varying attribute , which allows to describe continuous views inside any area or line covered by a spatial object or attribute.