Explanation/Reference:
A: The Oracle Spatial support for three-dimensional coordinate reference systems complies with the EPSG model, which provides the following types of coordinate reference systems:
Geographic 2D
Projected 2D
Geographic 3D, which consists of Geographic 2D plus ellipsoidal height, with longitude, latitude, and height based on the same ellipsoid and datum
Compound, which consists of either Geographic 2D plus gravity-related height or Projected 2D plus gravity-related height
B: Effective with Oracle Database Release 11.1, Oracle Spatial supports the storage and retrieval of three- dimensional spatial data, which can include points, point clouds (collections of points), lines, polygons, surfaces, and solids.
To use the subprograms in the SDO_PC_PKG Package (Point Clouds), you must understand the main concepts related to three-dimensional geometries, including the use of point clouds to model solids.
References: https://docs.oracle.com/cd/E11882_01/appdev.112/e11830/sdo_cs_concepts.htm#SPATL626
https://docs.oracle.com/cd/E11882_01/appdev.112/e11830/sdo_intro.htm#SPATL468