Because Teradata Database requires ordering functionality for UDTs, an ordering definition exists for the ST_Geometry type. In general, however, ordering ST_Geometry types by their ordering definitions is not useful or meaningful.
To determine spatial relationships between geometries, for example whether one ST_Geometry type is equal to another, the best practice is to use the ST_Geometry spatial methods, for example geom1.ST_Equals(geom2).
For details on ordering functionality, see "CREATE ORDERING" in Teradata Vantage™ SQL Data Definition Language Syntax and Examples, B035-1144.