There are several open source (free) utilities that help in predicting when the current operating system and database resources will eventually run out—known as forecasting. It is a worthwhile exercise whether you are testing new hardware, determining the amount of time left on the existing servers, or trying to test different I/O configurations. You will need to find a tool that provides different load simulators for different database types—OLTP, a web-based application, or a data warehouse. These tools are designed to put extreme loads on a system; be sure to test during off-times or on non-production systems.
I recommend using all of the free resources found on http://www.orapub.com. While it is a commercial company, they have a good reputation in the Oracle community. On their website, look for the link called Tools / Products. Using several of their free tools, I was able to determine that the new commodity hardware selected to replace an older...
