A "connect identifier" is an identification string of a single set of connection information to a specific target database instance on a specific Oracle server.

Connect identifiers are defined and stored in a file called tnsnames.ora located in $ORACLE_HOME/network/admin/ directory. Here is one example of a "connect identifier" definition:

ggl_XE =

(DESCRIPTION =

(ADDRESS =

(PROTOCOL = TCP)

(HOST = www.rendc.org)

(PORT = 1521)

)

(CONNECT_DATA =

(SERVER = DEDICATED)

(SERVICE_NAME = XE)

)

)

The above "connect identifier" defines "TNS_XE" with the following connection information:

* The network hostname: www.rendc.org.

* The network port number: 1521.

* The name of the target database instance: XE.