Techniques used in a relational database system for defining subclasses of built-in classes and thereby achieving columns in database tables which contain polymorphic objects of the built-in classes. The methods for the subclasses are contained in named packages. A table in the database system's schema relates the package name to a storage location managed by the relational database system that contains the compiled code for the package. When a method from the package is invoked, a dynamic linker uses the name and the table to locate the compiled code and then executes the compiled code. One thing that can be done with subclasses is to use a database system to automatically connect a Web user with a server of streaming data. The connection thus established is made by the server of streaming data to the Web user and thus bypasses the database system.