Design and implementation of a concurrency control mechanism in an object-oriented database system

This paper presents a practical concurrency control mechanism - Object-Locking in OODBMS. Object-Locking can schedule transactions, each of them can be considered as a sequence of high level operations defined on classes. By the properties of parallelity and commutativity between high level operations, proper lock modes for each operation are designed and the compatibility matrix is constructed. With these lock modes, phantoms are kept away from databases and a high degree of concurrency is achieved.