Implementation and performance of multi-level transaction management in a multidatabase environment

The 2PC (two-phase commit) protocol together with strict 2PL (two-phase locking) can be considered as a de-facto standard for distributed transaction processing. However, 2PC is often unacceptable from a performance and execution-autonomy point of view. Multilevel transaction management offers an alternative solution that allows early commits of subtransactions and thus improves performance and execution autonomy. While the theory of this approach is well established, a practical evaluation in a multi-database environment is still lacking. This paper describes a prototype implementation and initial measurements that compare transaction processing with 2PC versus distributed multi-level transaction management. Although we used SQL in our examples, the concepts presented are applicable to any notion of distributed object management system