Oracle Forms:Client Server-Web

Oracle forms are proprietary platform for building database applications that make use of Oracle database. The reason for their popularity is their tight integration with Oracle database. Although you can make use of other more strong development environments while still using Oracle like .Net and J2EE etc, Oracle forms are by far the most conventional and easy to use environment for database applications that use Oracle database at the back end. Oracle provides a complete development environment rather then just forms. The suite includes Oracle reports, Oracle Designer, Oracle Schema Builder, and Oracle Query Builder among others. From 9i onwards this suite has taken a huge turn in terms of its runtime environment.

Although development environment is not much changed since the release of 6i but runtime environment is changed from client/server to web. Oracle developer suite 10g now uses Oracle Application Server Forms Services for the deployment of Forms applications. Now instead of client/server it uses three tier architecture. Three tiers are as follows:

1. Client Tier

2. Middle Tier

3. Database Tier

Client tier consists of low end machines with some browser installed so that they can view the forms. Oracle provides a utility named as JInitiator for running forms in browser. JInitiator gets installed on the client machine when you run your first form. Client requests the application through middle tier which is typically Application Server. Application Server uses some Java Servlet for processing requests. This middle tier has dual role to play in the entire Forms Services Architecture. It acts as a server to the client tier and as a client to the database tier. And finally the database tier holds all the company’s data.

This new architecture completely changes the way user log in to use the applications. In the client server environment all the user’s credentials were normally stored in the database; so the authentication process was done through database. This has changed. Although you can still use this technique but Oracle recommends you to use the application server’s security implementations. Oracle AS uses the Oracle Internet Directory (OID) as the central repository for all users’ information. The connection string of every user is maintained through Connect Access Descriptors (CAD) in OID. If you use this technique for authentication then you can make your applications to leverage the Oracle AS’s Single Sign On features.