Today, a customer asked such a question, saying is a normal user, with Create system permissions and select any Table permissions, and the database version is 8174. But the user can see the username and password of the public dblink. Can you encrypt it?
DBLINK's password is stored in the Link $ view. If the ordinary user is given Select Any Table permissions, the O7_DICTIONARY_ACCESSIBILITY parameter is set to TRUE. Then the user will have the right to query the Lin $ View to know the password.
To make ordinary users (non-sysdba) can't find Link $, set the parameters to false.
Refer to Oracle Distributed Database.
