Oracle Essentials: Oracle9i, Oracle8i and Oracle8, Second Edition

Dynamic Services

Dynamic Services (DS) were introduced with Oracle8i and are included in Oracle9i. Essentially, Dynamic Services allow you to use any source of data as a service. Dynamic Services let you access data from non-Oracle sources, such as a web site, an exchange, or a mobile data source.

Dynamic Services use XML to define the format of the target data. Dynamic Services are registered with the Oracle Internet Directory, which provides access to the necessary XML descriptions used to define the data source. A Dynamic Services Engine uses these documents to coordinate and execute requests for the data from DS. Oracle9i includes a client-side API that allows you to access any type of data through DS in the same way, and a monitor that lets you watch the use of DS in the database.

You can combine multiple DSs into a compound Dynamic Service, or you can extend a simple DS by adding failover or conditions. Dynamic Services can be automatically accessed through a portlet in Oracle9iAS Portal. (See the discussion of Portal later in the chapter.)

Oracle9i comes with a DS wizard that lets you create a Dynamic Service by simply describing the source of the data; the wizard creates all the underlying XML documents needed.