In this thesis, object multiversion timestamp ordering (OMVTO) protocol is proposed as the concurrency control for object-oriented databases (OODB). It extended already proposed multiversion timestamp orderings (MVTO) for the consistency of instances and class objects in OODB, It preserves the serializability of transactions using object's multiversions. In case OMVTO is used for concurrency control, the overhead of version control is expected to decrease because OMVTO provides both concurrency control and version control. For performance analysis, OMVTO is compared with multigranulality locking protocol (MGLP) that was used in the ORION system, using simulation approach. According to the simulation results, OMVTO outperforms MGLP in the case that the schema evolution of database is not frequent.
