Efficient Optimistic Concurrency Control for Mobile Real-Time Transactions in a Wireless Data Broadcast Environment

Abstract

In this paper, we introduce a variant of the optimistic concurrency control protocols. The broadcast cycle is divided into multiple sub-cycles. Between two sub-cycles, there is a reserved space to accomodate identities for all the data objects which are updated by transactions in the server after the first sub-cycle begins. A read-only mobile transaction can validate its consistency autonomously by comparing its read-set with the committed write-set of the update transactions. If a read-only transaction cannot pass the partial validation, it is not simply aborted and restarted. Instead, an enhanced forward validation policy is applied, which help read-only transactions have more chances to commit. Extensive experiments are conducted to evaluate the performance of the proposed algorithms.