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

Cross-platform representation

There are two aspects to representing spatial data in a standards compliant, cross-platform manner:

  • Geometry type definition (what can be represented and stored)

  • Internal geometric description (how each object is physically described)

These will be covered in the following sections:

Outlining the SQL/MM ST_GEOMETRY type

The SQL/MM standard provides access for the database designer and developer to a geometry type hierarchy that can be used for both storage and application development. This is shown by the following diagram.

Oracle's MDSYS.ST_GEOMETRY is a database implementation of this SQL/MM geometry hierarchy, whose actual implementation is depicted graphically as in the following diagram (created using SQL Developer's Data Modeling extension).


The MDSYS schema prefix is actually not needed for the Oracle SQL/MM types due to the presence of global synonyms and as long as no other object has the same name in the current connected schema.

As can be seen Oracle...