The extended enterprise environment depicted in Figure 1 represents today's data processing installations. Such an environment often includes both centralized hosts and distributed workstations or hosts connected in a network. Gateways provide connections to LANs. These LANs can serve any computing systems architecture.

Figure 1. Extended Enterprise Environment

Most applications in an extended enterprise tend to share data to some degree. The trend toward sharing data will grow as workstations become more powerful, networks become more widespread, and applications are written that exploit these capabilities. The evolution of the distributed environment has created the following new requirements for accessing remote data.