Execution Dependencies in Transaction Closures

Activities of advanced applications can be modeled by interrelated transactions. These relations can be described by diierent kinds of transaction dependencies. The notion of transaction closure is a generalization of nested transactions providing means to describe complex activities such as transactional workkows. In this paper, our main focus lies on execution dependencies for describing certain control ows among related transactions of transaction closures. In particular, we consider the transitivity property for all kinds of transaction execution dependencies and discuss their relationship to other kinds of dependencies such as transaction termination dependencies. We point out that some of these dependency combinations are incompatible. As a result we present rules for reasoning about the transitivity of execution dependencies. Thus, we are able to conclude how arbitrary transactions of a transaction closure are transitively interrelated.