1、A client program with a graphical user interface that connects to the database
2、A data access system that provides record locking and a flexible search mechanism
3、Network server functionality for the database system
结构：
1、The main architecture of the application must be a traditional client-server system. There are three key parts: the server-side data management system, the client-side GUI, and the network connection between the two.
2、The program must be able to work in a non-networked mode. In this mode, the database and GUI must run in the same VM and must perform no networking, must not use loopback networking, and must not involve the serialization of any objects when communicating between the GUI and database elements.
The operating mode is selected using the single command line argument that is permitted. Architecturally, this mode must use the database and GUI from the networked form, but must not use the network server code at all.
