Towards a General Theory of Advanced Transaction Models in the Situation

We propose a theory for describing, reasoning about, and simulating transaction models that relax some of the ACID properties of classical transactions. Such models have been proposed for database applications involving long-lived, endless, and cooperative activities. Our approach appeals to non-Markovian theories, in which one may refer to past states other than the previous one. We illustrateour framework by formalizing closed nested transactions (CNTs). We first formulate CNTs as a suitable non-Markovian theory. Then we define a legal database log as one whose actions are all possible and in which all theCommit and Rollback actions must occur whenever they are possible. After that, we show that the relaxed ACID constraints are properties of legal logs and logical consequences of the theory corresponding to the CNTs. Finally, we use such a specification as a background theory for transaction programs written in the language GOLOG.