ESCC: a new deadline-driven extension of the SCC protocol

摘要

In Real-Time DataBase Management Systems (RT-DBMSs), both the integrity constraints of the database and the temporal constraints of the transactions must be respected. In this paper, we focus on the real-time concurrency control protocol SCC which combines the advantages of both pessimistic and optimistic concurrency control methods. This protocol distinguishes two kinds of transaction conflicts: the write-write conflicts resolved by the TWR (Thomas Write Rule [1]) method and the read-write and write-read conflicts resolved by the transaction duplication. In this paper, we propose to extend this protocol in two ways: (1) the TWR method is, to our mind, not applicable in real time context and (2) we propose a new deadline-driven method combined with the transaction duplication. Thus, more transactions will meet their deadlines.