Uncovering Database Access Optimizations in the Middle Tier with TORPEDO

A popular architecture for enterprise applications is one of a stateless object-based server accessing persistent data through Object-Relational mapping software. The reported benefits of using Object-Relational mapping software are increased developer productivity, greater database portability and improved runtime performance over hand-written SQL due to caching. In spite of these supposed benefits, many software architects are suspicious of the "black box" nature of O-R mapping software. Discerning how O-R mapping software actually accesses a database is difficult. The Testbed of Object Relational Products for Enterprise Distributed Objects (TORPEDO) is designed to reveal the sophistication of O-R mapping software in accessing databases in single server and clustered environments. TORPEDO defines a set of realistic application level operations that detect significant set of database access optimizations. TORPEDO supports two standard Java APIs for O-R mapping, namely, Container Managed Persistence (CMP 2.0) and Java Data Objects (JDO). TORPEDO also supports the TopLink and Hibernate APIs. There are dozens of commercial and open-source O-R mapping products supporting these APIs. Results from running TORPEDO on different O-R mapping systems are comparable. We provide sample results from running TORPEDO on popular O-R mapping solutions. We describe why the optimizations TORPEDO reveals are important and how the application level operations detect the optimizations