It seems an odd thing that so many facilities on the cloud environment take advantage of the concept of stored database credentials when it comes to authenticating/authorising access to those facilities, but a database link on your on-premise database typically will still require the username and password hard-coded as part of the DDL in the CREATE DATABASE link command. That creates a nuisance when you are wanting to deploy scripts securely.
But you’ll be pleased to know you can now also use a stored credential for your database links, eg
SQL> exec dbms_credential.create_credential('SCOTT_CRED', 'SCOTT', 'tiger') PL/SQL procedure successfully completed. SQL> create database link mydblink connect with SCOTT_CRED using 'pdb21a'; Database link created. SQL> select * from dual@mydblink; D - X SQL>
Full disclosure: The capability actually arrived in 21c, but since 99% of you are on 19c it is likely the first time you can start to take advantage of it is once you upgrade to 26ai.
Similarly, there is probably a huge stack of other 21c features that you’ve never explored, that its probably time to go back and take a look at as you plan your upgrades to 26ai.
Enjoy!