Real-time database systems are needed in many important applications such as program trading in the stock market, telecommunications, computer integrated manufacturing, advanced process control, intelligent highway systems, and various multimedia applications. Most current real-time database technology consists of fairly simple extensions to basic database protocols and is only applicable to soft real-time applications. This work extends real-time database technology to more sophisticated levels by utilizing an abstract data type model, nested transactions, distributed systems, and both soft and hard real-time constraints. The work compares the use of an active database paradigm with the more traditional approach. Integrated solutions across concurrency control, commit protocols, cpu scheduling, I/O, deadlock resolution, and communication are stressed. The research approach is largely experimental and uses testbeds built with prior NSF awards. Results from this project can create more efficient, profitable, and safer real-time database applications.
