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

Coordinate system transformation techniques

As we have seen in the first section of this chapter, it is very common to do coordinate system transformations as part of the data loading process. Many of the external data loading tools provide these transformations, but sometimes it is convenient and more efficient to do these transformations in the database. Oracle Spatial provides two distinct methods for doing coordinate system transformations. The SDO_CS.TRANSFORM function works on one row at a time to transform a geometry, while the SDO_CS.TRANSFORM_LAYER function works on a whole table of data and transforms all the geometries in a column of the table. Both methods support different use cases: the transform function is mainly used in dynamic query situations, while the TRANSFORM_LAYER function is mainly used in bulk update or bulk loading situations. As we are describing data loading techniques in this chapter, we will describe how both these methods can be used in bulk data loading situations...