Dynamic versus static locking in real-time parallel database systems

Summary form only given. Parallel database systems are capable of providing significant performance gains in terms of transaction processing rates. These gains are realized by running many transactions concurrently. A requirement in real-time transaction scheduling is to complete the transactions within their deadline. Due to its simplicity, two-phase locking (2PL) is one of the most commonly used concurrency control mechanism. Two alternative methods of securing locks in the 2PL protocol are static locking or dynamic locking. We report performance of the two locking variants of the 2PL protocol under various degrees of resource and data contention in a real-time parallel database system.