3.2.3 Understanding Net Service Alias Entries

Directory naming enables you to create network service alias entries in addition to database service and network service name entries. A network service alias is an alternative name for a network service name or database service. A network service alias entry does not have connect descriptor information. Instead, it references the location of the entry for which it is an alias. When a client requests a directory lookup of a network service alias, the directory determines that the entry is a network service alias and completes the lookup as if it is the referenced entry. For example, in the following figure, a network service alias of db1alias is created for a database service of db1. When db1alias is used to connect to a database service, as in CONNECT username@db1alias, it will actually resolve to and use the connect descriptor information for db1.

Figure 3-9 Net Service Alias db1alias in a Directory Server

Description of "Figure 3-9 Net Service Alias db1alias in a Directory Server"

There are several uses for network service aliases. As shown in Figure 3-9, a network service alias can be useful as a way for clients to refer to a network service name by another name. Another use is to have a network service alias in one Oracle Context for a database service or network service name in a different Oracle Context. This enables a database service or network service name to be defined once in the directory server, but referred to by clients that use other Oracle Contexts.

In Figure 3-10, database service db1 resides in dc=jp,dc=example,dc=com. A network service alias named db1 is created in dc=us,dc=example,dc=com. This enables clients in both Japan and the United States to use the connect string CONNECT username@db1 as opposed to clients in the Unites States needing to specify CONNECT [e-mail].

Figure 3-10 Net Service Alias db1 in a Directory Server

Description of "Figure 3-10 Net Service Alias db1 in a Directory Server"