Building Oracle XML Applications

What Is interMedia?

interMedia is a family of database extensions that allows Oracle8i to more effectively manage multimedia types such as images, movies, sound clips, and documents. interMedia Text is the component of interMedia that enables searching XML documents, document fragments, and other document content. While the interMedia extensions are technically a separate product, they are included on the Oracle8i CD and can be installed and used at no additional cost. The examples in this chapter require and assume that interMedia Text has been installed in your Oracle8i Release 2 (8.1.6) database.

The main feature of interMedia Text is scalable full-text search—that is, the ability to quickly search through a huge number of documents and find those that contain a certain word or phrase, like a web search engine. Let’s walk through an example, returning to our claim table. We want to do XPath contains()-like full-text searches on the damagereport column. The first step is to build a specialized index on the column:

CREATE INDEX damagereportx ON claim(damagereport) INDEXTYPE IS ctxsys.context;

Tip

interMedia Text versions 8.1.5 and 8.1.6 use PL/SQL external procedures for indexing. This means that in order for a CREATE INDEX to work, you need to have a Net8 listener running and configured to invoke external procedures. If the listener is not running or is not properly configured, the CREATE INDEX statement will fail with the error message:

DRG-50704: Net8 listener is not running or cannot ...