Transaction Identifiers in Nested Transactions: Implementation Schemes and Performance

In this paper, we address a speci"c topic within the context of nested transaction implementation, namely, the assignment of identi"ers to transactions. We discuss the most important information such identi"ers should carry. We do this based on an analysis of the main requirements the components of a general transaction processing system pose on the identi"ers. Thereafter, we present some schemes for the assignment of transaction identi"ers and discuss their pros and cons with regard to the requirements presented. Finally, we compare one of our schemes to a conventional one by considering the most common operations that are performed with the identi"ers. Lastly, we show the performance measurements we have obtained.