Book Image

Applying and Extending Oracle Spatial

Book Image

Applying and Extending Oracle Spatial

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
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Table Comparing Simple Feature Access/SQL and SQL/MM–Spatial
Index

Translating, rotating, scaling, and reflecting


This section examines a collection of commonly used transformation functions that provide the ability to: move or translate a geometry from one location to another; rotate a geometry around a supplied point; scale or enlarge/shrink a geometry.

The standard method for implementing these is via the application of an affine transformation matrix.

Oracle Spatial did not provide such capability until 11g, when it provided the SDO_UTIL.AffineTransforms function. In 10g, Oracle released the UTL_NLA built-in SYS package (including UTL_NLA_ARRAY_DBL and UTL_NLA_ARRAY_INT types), which can be used to construct the appropriate affine transformation matrices to implement spatial transformations. (for Oracle 9i, implementation can be done with custom PL/SQL code, but it is not covered in this book.)

Both the SDO_UTIL.AffineTransforms and UTL_NLA-based approaches are provided in the source code associated with this book.

Introducing a set of transformation member...