Book Image

Applying and Extending Oracle Spatial

By : Siva Ravada, Simon Greener
Book Image

Applying and Extending Oracle Spatial

By: Siva Ravada, Simon Greener

Overview of this book

Spatial applications should be developed in the same way that users develop other database applications: by starting with an integrated data model in which the SDO_GEOMETRY objects are just another attribute describing entities and by using as many of the database features as possible for managing the data. If a task can be done using a database feature like replication, then it should be done using the standard replication technology instead of inventing a new procedure for replicating spatial data. Sometimes solving a business problem using a PL/SQL function can be more powerful, accessible, and easier to use than trying to use external software. Because Oracle Spatial's offerings are standards compliant, this book shows you how Oracle Spatial technology can be used to build cross-vendor database solutions. Applying and Extending Oracle Spatial shows you the clever things that can be done not just with Oracle Spatial on its own, but in combination with other database technologies. This is a great resource book that will convince you to purchase other Oracle technology books on non-spatial specialist technologies because you will finally see that "spatial is not special: it is a small, fun, and clever part of a much larger whole".
Table of Contents (20 chapters)
Applying and Extending Oracle Spatial
About the Authors
About the Reviewers
Table Comparing Simple Feature Access/SQL and SQL/MM–Spatial

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...