The objects are of different types according to their extension in space: point, line, surface and body like objects. These are called the geometrical types of the objects, shortly object types. In the database DAT occure the list three. Their definition is as follows:

• Point objects: objects of 0-dimension, which have positional data, but no extension in space or it is negligible from the point or view of DAT.
• Line objects: objects of 1-dimension, which are characterized by their linear extension, shape and location.
• Surface objects: objects of 2-dimensions, which have areal extension of 3 dimensions in space, but it is transformed of 2 dimensions by projecting into plane.

Geometrical types of objects occurring in the database DAT

Of point objects the data model DAT distinguishes real object point (e.g. triangulation point), surface point (e.g. geocode), and label point (e.g. pricking spot of a geographical name).

Among the geometrical types of objects it is also possible another kind of classification: simple and complex objects. The latter come into being by somewhat linking of simple (point, line and surface) objects.

Hierarchy of building relationship between simple and complex objects

EO_i - Simple objects
KO_i - Complex objects
KO - Multiple complex objects

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