Spatial Data Warehouses - Data Warehouse Systems: Design and Implementation - page 440

Fig. 11.15 Logical representation of the GeoNorthwind data warehouse in Fig. 11.4
We remark that the abstract spatial types presented in Sect. 11.1.1 must
be mapped into corresponding spatial types provided by the implementation
platform at hand. For instance, while at the conceptual level the Line
data type in Fig. 11.1 represents arbitrary curves, such curves can only
be approximated with one of the subtypes of the ST Curve data type in
Fig. 11.14 .Inaddition,currentsystemsdiffer in the set of spatial types
provided. For instance, while PostGIS provides types similar to those of the
SQL/MM standard presented in Sect. 11.3.2 , Oracle provides a unique data
type SDO Geometry that must be parameterized for defining different types
of geometries.