Concurrency control in object-oriented databases: A mechanism and a performance study.

Abstract

Object-oriented databases are becoming increasingly popular in businesses. Some areas of interest include formal object-oriented database models, query optimization, analysis and design techniques, and concurrency control. These issues have been addressed as they pertain to the relational model and to centralized databases but they have not been addressed as they apply to the object-oriented model. This dissertation involves the development and testing of a lock-based concurrency control (CC) mechanism specifically designed for an object-oriented database. The mechanism is named O²C² pronounced oh-two see-two. After the O²C² development is introduced, a proof of correctness is presented to demonstrate that the schedules it produces are equivalent to serializable ones. A discussion ensues concerning simulating O²C² under varying conditions of contention (from very little contention to high contention) to measure its performance in terms of completed transactions per second. This research was conducted in three phases: model development and implementation, simulation to test the model, and analysis of the results. First, CC issues specific to object-oriented databases were developed and applicable models created. Next, the simulation phase was conducted using a specific transaction model. In the third phase, an analysis of the simulation results demonstrates how the mechanism performs under specific conditions.