Oracle has published a technical white paper specific to load testing using OpenScript/OLT. We would recommend all ATS load testing users to go through this white paper as it not only helps provide a better picture of what happens behind the scenes but also helps in troubleshooting most common issues. Here is the excerpted summary of the white paper.
"This paper addresses the inner workings of Oracle Load Testing (OLT) and also highlights the optimal configuration to create load test scripts and scenarios. It looks into the aspect of creating robust load test scripts and focuses on the architecture and life cycle of Oracle Load Testing. The runtime aspects of OLT and the behavior of databank record during load tests will also be discussed."