Implementing Reflective Access Control in SQL

Reflective Database Access Control (RDBAC) is a model in which a database privilege is expressed as a database query itself, rather than as a static privilege in an access control matrix. RDBAC aids the management of database access controls by improving the expressiveness of policies. The Transaction Datalog language provides a powerful syntax and semantics for expressing RDBAC policies, however there is no efficient implementation of this language for practical database systems. We demonstrate a strategy for compiling policies in Transaction Datalog into standard SQL views that enforce the policies, including overcoming significant differences in semantics between the languages in handling side-effects and evaluation order. We also report the results of evaluating the performance of these views compared to policies enforced by access control matrices. This implementation demonstrates the practical feasibility of RDBAC, and suggests a rich field of further research.