Suppose that on server A you have three databases in three separate home directories: Oracle7 (7.3.4), Oracle8 (8.0.6), and Oracle8i (8.1.6). On server B you have three other databases in three separate home directories: Oracle8 (8.0.4), Oracle8 (8.0.5), and Oracle8i (8.1.5).

In this configuration, you can have an Oracle7 client connecting to Oracle7 on server A and to release 8.0.4 on Server B. Another Oracle7 client is connected to all three databases on server A and to release 8.0.5 on server B.

In addition, a release 8.0 client connects to Oracle7 on server A and to releases 8.0.4 and 8.0.5 on server B. Another release 8.0 client connects to 8.1.6 on server A and to 8.1.5 on server B.

Finally, a release 8.1 client connects to 8.1.6 on server A and to 8.0.5 and 8.1.5 on server B.