Improving Transaction-Time DBMS Performance and Functionality

Immortal DB is a transaction time database system that is built into a commercial database system rather than being layered on top. This enables it to have performance that is very close to the performance of an unversioned current time database system. Achieving such competitive performance is essential for wide acceptance of this temporal functionality. In this paper we describe further performance improvements in two critical dimensions. First Immortal DB range search performance is improved for current time data via improved current version storage utilization, making this performance essentially the same as unversioned performance. Second, Immortal DB update performance is increased by further reducing the cost for the timestamping of versions. Finally, we show how a simple modification, integrated into the timestamping mechanism, can provide a foundation for auditing database activity. Our algorithms have been incorporated into a commercial database engine and experiments using this database engine demonstrate the effectiveness of our approach.