3D Operations in DBMS

Although it is possible to maintain objects with 3D coordinates, the functions implemented still omit the z-value.Some exceptions are PostGIS and MapInfo Spatialware Datablade (based on Informix) that do support geometry calculation such as 3D length and 3D perimeter in 3D. Existing spatial functions are developed only on the basis of a geometry model (with exception Oracle Spatial 10g), but they still can perform topological operations such as overlap, touch, etc.

The problem with 3D operations is twofold: first, the existing operations have to extend to consider the z-coordinate, and second, new operations have to be developed on the basis of topological models.

Furthermore, since the two models (geometry and topology) are to be maintained in DBMS, operations for conversion between the two has to be ensured, i.e.operators for building topology and operators for realization of geometry.