Real-time update of access control policies, that is, updating policies while they are in effect and enforcing the changes immediately, is necessary for many security-critical applications. In this paper, we consider real-time update of access control policies that arise in a database system. Updating policy while they are in-effect can lead to potential security problems. In an earlier work, we presented an algorithm that not only prevents such security problems but also ensures correct execution of transactions. In the current work we extend that algorithm to handle addition and deletion of access control policies and provide the implementation details of the algorithm. We also describe properties of histories generated by this algorithm.