Anomaly Discovery and Resolution in MySQL Access Control Policies

Managing hierarchical and fine grained DBMS policies for a large number of users is a challenging task and it increases the probability of introducing misconfigurations and anomalies. In this paper, we present a formal approach to discover anomalies in database policies using Binary Decision Diagrams (BDDs) which allow finer grain analysis and scalability. We present and formalize intra-table and intertable redundancy anomalies using the popular MySQL database server as a case study. We also provide a mechanism for improving the performance of policy evaluation by upgrading rules from one grant table to another grant table. We implemented our proposed approach as a tool called MySQLChecker. The experimental results show the efficiency of MySQLChecker in finding and resolving policy anomalies.