ECA-Based Transaction Compensation - An Approach for Specifying and Executing Compensating Tran...

14.03.2002

Abstract
Recovery by compensating transactions has been suggested as an important component in several extended transaction models, especially within the domain of long-lived transactions, cooperating transactions and workflows. In this thesis we present a model for spesifying and executing compensating transactions within existing DBMSs. This model is based on ECA-rules, a concept implemented in active databases. ECA-rules add reactive behaviour to the DBMS, allowing events to be detected and reacted upon under certain conditions. Our model, in this thesis called ECA-based compensation, provides automatic compensation seen from the application point of wiew, and the compensation does not require modifications of the DBMS internals, but a certain level of support for ECA-rules must be present. Feasibility of this model is demonstrated in a prototype implementation running inside an off-the-shelf available DBMS (Oracle8). The model and implementation is discussed and contrasted with other existing approaches to transaction compensation.