In WebDB 2.X, users were synonymous with database user accounts. By default, a WebDB developer could create a component or object in his or her own database schema.
In Oracle Portal 3.0, users are typically mapped to a database schema for administrative purposes only. The ability to create a component in Oracle Portal 3.0 no longer depends on whether the developer has privileges to build components in a schema, but instead on whether the developer has privileges to build a component in an application.
The application itself maps to a single schema that stores the components created within the application. A developer who has privileges to create a component in an application is by default granted privileges to build components in the application's schema. Access to database objects is also based on the application schema's privileges. A Portal developer can access database objects such as tables, views, and procedures if the application schema has been granted access.
Migrating WebDB 2.X to Portal 3.0
By default, users created in Oracle Portal 3.0 map to a common database schema called <portal>_public, where portal is the name or the schema in which Oracle Portal is installed. However, a DBA has the option of mapping the Portal user to some other schema, for example to set up special access privileges to objects.
If you have upgraded Portal 2.X to 3.0 at your installation, you'll notice that all WebDB 2.X users have been automatically mapped to their original schemas.