Java Development Tools

In the article "How To Support Dynamic JDBC Credentials" (http://www.oracle.com/technology/products/jdev/howtos/10g/dynamicjdbchowto.html), the overview seems to describe that, in a dynamic jdbc credential scenario, rather than pooling database connections application modules are pooled. When an application module pulled from the pool has a database connection using credentials different from those of the current user, the connection is closed and reestablished with the current user's credentials. My questions is, what is the effective usage of database connection resources in this strategy? If a system has 20 application modules in the pool and 100 concurrent users, approximately 80% of requests would require reconnection to the database? In other words, is dynamic JDBC credentials with ADF more closely akin, in terms of database resource usage, to database connection pooling? To holding open connections in session? How well does this scale?

Any input would be really appreciated.

Thanks,
Jeff