What is mandatory access control?

In mandatory access control each data object is tagged or labeled with a certain classification level, and each user is given a certain clearance level. A given data object can then be accessed only by users with the appropriate, clearance. Mandatory schemes are, thus, comparatively rigid.

Most DBMS support either discretionary access control or mandatory access control or both. In fact most of the DBMS support discretionary control, and some systems support mandatory control as well, thus, discretionary control is, thus, more likely to be encountered in practice.