Hi,
By default the value of GLOBAL_NAMES is TRUE.You can create the database link even if the value of GLOBAL_NAMES is TRUE.
But when u create the database link when the GLOBAL_NAMES=TRUE the database link name should be same to the database to which it points.

e.g Say u have 2 databases database A and database B and you want to create database link from A -> B so u have to give the command

create public database link B
connect to scott identified by tiger using 'B';

In case of any help please be free to ask me at [email protected]

Regards,
rohit Nirkhe,Oracle DBA,OCP 8i
[email protected]