A deadlock checkpointing scheme for multidatabase systems

A multidatabase system (MDBS) is a software package that integrates a number of pre-existing, autonomous and heterogeneous local database systems (LDBS). Deadlock detection and resolution in MDBS is much more difficult than in traditional distributed database systems due to the autonomy requirement which implies that LDBSs cannot exchange any control information. The authors present an efficient periodic deadlock detection and resolution scheme for MDBS which allows for the concurrent execution of global transactions at multiple sites. The authors scheme employs a depth-first search of a bipartite graph called the transaction-block-at site graph (TBSG)