Improving the SCC protocol for real-time transaction concurrency control

For Real-Time DBMSs (RTDBMSs), both the integrity constraints of the database and the temporal constraints of the transactions must be respected. In this paper, we focus on the SCC real-time concurrency control protocol proposed by Bestavros et al. [1, 2, 3]. It is based on the duplication of the transactions and the use of the transaction timestamps to resolve the transaction conflicts. Despite its great performances in real-time distributed DBMSs [3], we propose an extension of the protocol to improve this performances in two ways: (1) the write-write conflicts are resolved with a particular method that is, to our mind, not applicable in real-time context and (2) for other conflicts, we propose an extended deadline-driven method combined with the transaction duplication. In this way, more transactions will respect their deadlines.