Maintaining quasi serializability in multidatabase systems

A scheduler producing quasi-serializable executions for concurrency control in multidatabase systems (MDBSs) is presented. An algorithm is proposed which ensures quasi-serializability by controlling submissions of global transactions. The algorithm groups global transactions in such a way that transactions in a group affect each other in a partial order. Transaction groups are executed separately and in a consistent order at all local sites. The algorithm differs from the others in that it does not violate local autonomy, provides a high degree of concurrency, and is globally deadlock-free.<<ETX>>