Concurrency Control, Version Management and Transactions in Advanced Database Systems

摘要

This document constitutes the final deliverable for the research project titled “An Investigation of Selected Issues in Transaction Mechanism Design for Object Oriented Databases.” The document describes our ideas for extending the traditional transaction concept for use in object oriented databases, and concentrates specifically on providing an underlying model to support the concurrency control and version management aspects of the problem. The ideas presented here are not however restricted to the domain of object oriented databases. They are more generally applicable to database systems that require flexibility in their versioning and concurrency control policies.In this document we define a model for change control, propagation and representation. A key aspect of the model is the separation of mechanism from policy. We describe an integrated collection of basic mechanisms that underlie version management, concurrency control, and change propagation. These mechanisms allow a variety of concurrency control, version naming, and change propagation policies to be implemented, and even support multiple different polices within the same system.