I just failed with 716

, this is the one and only cert I have ever failed! The exam seemed ok to me, but there were a lot of questions with what looked like several 'valid' answers, so I guess I made some bad calls.
Some of the questions pulled up some gaps in my studies and Im confused about. A few questions to ask...
What is the SQL security model based on? Users/Objects/Files? or Users/Files/Folders? or some other combination.
From Bell LaPadula, Clark-Wilson and BIBA. Which model is which in terms of MAC, DAC, RBAC?
Is RBAC multiple roles, mutliple users, single actions? or multiple users, single roles, multiple actions? or some other combination.
Any help appreciated.