Semantics-based asynchronous speculative locking protocol for improving the performance of read-only transactions

Speculative locking (SL) protocols have been proposed in the literature for improving the performance of read-only transactions (ROTs) without correctness and data currency issues. In these protocols, ROTs carry out speculative executions and update transactions (UTs) follow two-phase locking (2PL). In these protocols, UTs are blocked if they conflict with ROTs. To reduce blocking of UTs, semantics-based protocol has been proposed in the literature by exploiting the "compensatability" property of ROTs. In that protocol compensatable ROTs are processed without blocking and non-compensatable ROTs are processed by using synchronous speculation method. In this paper, we have proposed a semantics-based speculative locking protocol for ROTs in which non-compensatable ROTs are processed with asynchronous speculation method. The simulation results show that the proposed approach improves the performance of ROTs over other protocols.