Chapter 6. Implementing New Functions

To create new functions that use and extend those offered by Oracle's Spatial and Locator products, the SDO_GEOMETRY object, its attributes and its structure must be thoroughly understood. Therefore this chapter will start by building some functions that will help you understand, access, and process an SDO_GEOMETRY object's attributes. In building these functions, those Oracle SDO_GEOMETRY methods and SDO_GEOM and SDO_UTIL package functions that relate to the processing of the SDO_GEOMETRY attributes and structure, will be introduced and used. This chapter will present information that will help the reader understand how to:

• Expose or create additional properties for the SDO_GEOMETRY object

• Manipulate the SDO_ORDINATE_ARRAY in SQL and PL/SQL

• Create functions to expose SDO_ELEM_INFO_ARRAY properties

• Use SDO_ELEM_INFO_ARRAY to process SDO_ORDINATE_ARRAY correctly

• Organize functions via object types and packaging

• Sort geometries

Later chapters will build on the...