부산대학교 도서관

Transaction priority is a critical feature for real-time database systems. This prioritization mechanism is widely implemented, particularly in locking-based concurrency control protocols. Plor is a non-real-time concurrency control protocol based on the 2-phase locking protocol. Plor utilizes the Wound-Wait scheme, a timestamps-based scheme for deadlock prevention, as it provides lower tail latency. One problem of Plor is that it requires transactions to fetch timestamps from a single centralized atomic counter. This paper evaluates the implementation of the Fair Thread ID method (FairTID), in which transactions use the thread IDs as their timestamps instead of fetching timestamps in 2-phase locking protocols and maintain the prioritization inherited from the Wound-Wait scheme. The FairTID method shows up to 1.5 times throughput improvement while reducing latency by 1.6 times and deadline-miss ratio by 1.67 times over the baseline protocol. The method displayed significant improvements in performance while the level of contention was not high.