Oracle Web Applications: PL/SQL Developer's Intro

Chapter 4. Oracle Application Server (OAS)

Oracle Application Server (OAS) is Oracle’s enterprise web platform. While OAS performs all the functions of a normal web server, its main advantage is its tight integration with a backend Oracle database. After starting life with the name Oracle Webserver at version 1, then becoming Oracle Web Application Server at version 3, the Oracle Application Server, now at version 4, has steadily grown in size and features.

Tip

The resources required to run OAS have increased along with the new features. For example, the memory requirements (on NT, at least) went from 48 MB in version 3 to 128 MB in version 4.

In this chapter, we’ll look at the architectural components of OAS as they relate to PL/SQL application development. Be sure that you’ve read Chapter 2, which introduces the basic concepts behind the web infrastructure on which OAS is built. We’ll start with a discussion of how OAS returns web resources to a user’s browser. Then we’ll look at the PL/SQL cartridge, an OAS component we can use to develop PL/SQL applications.

How OAS Returns Web Resources

OAS has three methods to return resources. The first simply uses a directory mapping system to send static files to the client’s browser. The next two methods return dynamic resources: one executes resources using the standard CGI interface, and the other, the Web Request Broker (WRB), executes resources using a program called a cartridge.

As we saw in the previous chapter, the HTTP listener ...