Synchronization and Recovery in Cooperative Transactions

Traditional atomic transactions do not work well in databases used by design applications. A typical design task is divided into parallel subtasks that are interdependent. We relax the constraint of atomicity in these situations to allow cooperative transactions to work together in groups to accomplish design tasks in the database. These groups may be arbitrarily nested to form a cooperative transaction hierarchy. We examine the notions of correctness, synchronization, and recovery within a single group in the cooperative transaction hierarchy. Each cooperative transaction in a group maintains only partial consistency in the database, and shares data with other transactions in the group in a way that may violate the atomicity of each. We define a programmable mechanism to allow a database administrator to specify and enforce the correctness of the cooperative transactions in a group. We also define a mechanism for recovery when a cooperative transaction aborts or fails.