Modeling the effects of data and resource contention on the performance of optimistic concurrency control protocols

The authors use a mean value model for data contention and a piecewise linear model for resource contention. To show the usefulness of this methodology, they compare three different optimistic concurrency control protocols for a centralized system. The authors derive a closed-form expression for the transaction throughput as a function of workload parameters and the resource-access-time parameters. The resource-access-time parameters can be derived using a simple analytical model. The closed-form expressions are very useful as a quick evaluation of different protocols and to gain insight about protocol performance over a wide range of model parameters. They also yield a simple asymptotic analysis of the optimistic concurrency control protocols. The authors apply the methodology to predict the performance of a testbed database system