I recently installed Ataccama DQ Analyzer with the Derby database out of the box. I am trying to setup drill through, but not sure what is the default database name, username and password.
You can specify any database, username/password that you like in the drill through and it would work. By default, the property being used allows you to create any database you want and use any credentials to authenticate.
Alternatively, you can check what the username and database it uses as default from expanding the database folder on the left side and clicking on DB. You can enter anything as a password and it would accept it.
Please see screenshot below