GLOBAL COMMITTABILITY IN MULTIDATABASE SYSTEMS

In this paper we develop a formal basis for research into the reliabil ity aspects of transaction processing in multidatabase systems. We def ine a new correctness notion called global committability (GC) for the correct unilateral commit and retry recovery of global transactions i n an autonomous MDBS environment. This notion facilitates to ensure th e isolation property of global transactions when the retry approach is applied. The formalization work illustrates that conventional seriali zability (SR) notion and recoverability (RC) notion are not sufficient to specify a correct execution (i.e., isolated execution and recovery ) of global transactions when the unilateral commit and the retry reco very are used to ensure the atomicity of global transactions. This wor k is significant because the unilateral commit and the retry recovery is an attractive complementary means to the undo recovery (whose corre ct schedule is specified by the conventional RC notion) for advanced t ransaction applications with characteristics of site autonomy and long -lived execution.