Summary

The chapter first showed how a standardized geometry type and methods can aid in the creation of solutions to spatial problems that can not only run on just one database, but also with editing, any other database supporting that common geometry data type, internal description, and methods that derive from the SQL/MM and OGC SFA 1.x standards.

The issues for data storage that arise from having singly inherited and multiply-inherited geometry data types were examined with a common approach for using all three databases and their types presented.

Oracle's ST_GEOMETRY hierarchy imposes a highly standardized approach to object declaration and use, whereas PostgreSQL's and SQL Server 2012's singly inherited types provide partial implementations of the same standards. This can be seen in the execution of methods like ST_Area against non-polygon geometry objects, while Oracle does not allow inappropriate method execution. In addition, Oracle does not allow ST_GeometryN and ST_NumGeometries...