Queueing models of concurrency control in database with Poisson arrivals

Abstract We study the mean performance of concurrency control in database with Poisson arrival. The computer system is formulated as open queueing systems with two cases, no waiting room case and unlimited waiting room case. To avoid the complexity of the state space, we propose two aggregate models, birth-death process and quasi-birth-death process, to predict system performance. The death rates of two models are defined by the throughput of closed systems. Instead of DC-trashing appeared in closed system, we obtain the monotonicity of response time and loss probability in birth-death models. From these properties we can obtain the optimal of multiprogramming level. In quasi-birth-death models we give the algorithms to calculate the equilibrium probability. We obtain numerical results from both analytic model and computer simulation. Comparisons show that the results of birth-death models and quasi-birth-death models are very similar, and the predictions of our models fit well with the simulation results.