Semantic-Based Concurrency Control in Object-Oriented Databases

In this paper, we present a concurrency control mechanism that deals with three important issues in object-oriented databases (OODBs): semantics of methods, nested method invocation and referentially shared object. In our scheme, locks are required for the execution of methods instead of atomic operations. By doing this, we reduce the locking overhead and deadlocks due to lock escalation. Especially, if a method invokes one or more methods on the same object during its execution, our scheme does not incur additional overhead for those invoked methods. Also, we provide a way of automating commutativity of methods. In addition, we further increase concurrency with the use of runtime information.