Real-Time Databases: Issues and Applications

Data in real-time databases has to be logically and temporally consistent. The latter arises from the need to preserve the temporal validity of data items that reflect the state of the environment that is being controlled by the system. Some of the timing constraints on the transactions that process real-time data come from this need. These constraints, in turn, necessitate time-cognizant transaction processing so that transactions can be processed to meet their deadlines. This paper explores the issues in real-time database systems and studies two real-time database applications: Cooperative distributed navigation systems and Network services database systems. The purpose of the paper is to discuss the general characteristics of data and transactions in real-time database systems and further explore them in the context of these two applications. Cooperative distributed navigation systems appear in several complex applications such as road following and robot navigation. Network servic..