Information integration has two fundamental aspects, data integration and function integration. Function integration is based on flow technology and adapter technology, and both of these add powerful capabilities to information integration. They provide access to a huge variety of data sources, such as standard applications, home-grown backend systems, and Web services. For accesses that are not restricted to read operations, flows can help in managing units of work across these data stores. When a database system is coupled with a flow engine, all of these capabilities are made available to database applications.