If the Oracle server name or the logon account name for the Oracle server changes, you must update the media server's list of Oracle servers and authentication credentials. Make the same changes on the Oracle server by using the Remote Agent Utility to configure instance information and database access.
The logon account name must have administrative rights or backup operator rights to the Oracle server. If the user name is incorrect or is not provided, or if it does not have the appropriate rights, then you cannot perform Oracle backup or restore operations to that computer.
To edit an Oracle server name or a logon account on the media server's list of authentication credentials
More Information
Configuring database access on the media server for Oracle operations
Configuring the Oracle Agent on Windows computers