In a standalone system, the client and server programs run on the same machine. In a networked system, there is one server machine, and several client workstations. DP4 also supports configurations that use multiple servers. This facility is used for two types of application:
You can set up a resilience scheme, to ensure the non-stop working of your application. Resilience is very important in retail and banking applications where a network failure can otherwise mean a halt in trading
You can set up a distributed database, in which database tables reside on different machines. For example, you may locate frequently used tables on the workstation, and the remaining tables on the server machine
The following sections explain how DP4 is set up on a standalone machine, and on a simple network. Make sure you understand how these environments work before you consider the alternative ways of setting up your system. These standalone and networked systems are used as the basis for the more complex systems that use resilience and database distribution.