Have a crack at this Object-Oriented DBMS test and check out your world rank based on your performance. If you perform bad then no need to worry. You will get a detailed analysis of your performance so that you can improve and hit back in next attempt.
Memorize the concepts you learnt about Object-Oriented DBMS in your classes and attempt this free online test on Object-Oriented DBMS. You can attempt this test multiple times and improve your score.