Speculation-based protocols for improving the performance of read-only transactions

A read-only transaction (ROT) does not modify any data. The main issues regarding processing of ROTs are correctness, data currency and performance. Even though the popular two-phase locking (2PL) protocol processes the ROTs correctly with no correctness related issues, its performance deteriorates as data contention increases. Snapshot isolation (SI)-based protocols have been proposed in the literature to improve the performance. However, the SI-based protocols compromise both correctness and data currency aspects. In the literature, speculative locking (SL) approach has been proposed to improve the transaction performance in online transaction processing environments. In this paper, we have proposed efficient speculation-based protocols to improve the performance of ROTs by exploiting features specific to ROT environment. The performance results show that the proposed protocols improve the performance of ROTs over 2PL and SI-based protocols with manageable extra processing resources. Further, the proposed protocols process transactions without any correctness and data currency related issues.