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

Understanding and using SDO_ELEM_INFO


The new functionality created so far did not require looking at the logical structure of an SDO_GEOMETRY object, as described by the SDO_ELEM_INFO attribute. Understanding and being able to process the contents of this VARRAY is important, when developing or implementing more complex functionality.

The SDO_ELEM_INFO (see "2.2.4 SDO_ELEM_INFO", in the Oracle® Spatial Developer's Guide 11g Release 2 (11.2)) attribute is organized as a set of elements, each having three values or members. Each member of a triplet has a name: SDO_OFFSET (actually SDO_STARTING_OFFSET), SDO_ETYPE, and SDO_INTERPRETATION. These members are described in the "Section 2.2.4 SDO_ELEM_INFO", in the Oracle® Spatial Developer's Guide 11g Release 2 (11.2) (edited) by the following Table:

SDO_OFFSET

Indicates the offset within the SDO_ORDINATES array where the first ordinate For this element is stored.

SDO_ETYPE

Indicates the type of the element. values 1, 2, 1003, and 2003 are considered...