A transaction processing model for performance analysis in multilevel-secure database systems

Although many concurrency control schemes have been developed, a thorough understanding of their actual performance is not enough. Numerous performance studies in non-secure centralized databases have been done in the past decade. However, their results cannot be directly applied to multilevel-secure databases, since in addition to single-level concurrency control, multilevel-secure databases deal with new problems of convert channel due to read-down conflict operations. Investigating their impact on transaction scheduling is a crucial issue. The concurrency control requirements for tran-saction processing in an MLS/DBMS are different from those in conventional transaction processing systems with respect to inclusion of covert-channel freeness. In particular, there is the need to coordinate transactions at different security levels avoiding both potential covert timing channels and the starvation of transactions at high security levels. Using a secure transaction processing model, we can evaluate the throughput and response time characteristics of multilevel-secure concurrency control schemes under a wide variety of database workloads and system configurations.