Head nodes are used to host applications that may not typically be thought of as part of database management systems. Head nodes extend the functional capabilities of the DBMS to include sophisticated and specialized software capabilities that might otherwise be beyond the domain of commodity DBMS features. Examples are Web application servers and business intelligence solutions. Head nodes are often implemented using discrete hardware and operating system configurations (for example, an Intel processor running Windows XP). These systems might be installed directly in the DBMS chassis or as a separate computer system that is directly connected to the DBMS.
