Database and database systems have become an essential part of everyday
life, such as in banking activities, online shopping, or reservations of
airline tickets and hotels. These trends place more demands on the
capabilities of future database systems, which need to evolve into
decision making systems based on data from multiple sources with varying
reliability. In this book a model for the next generation of database
systems is presented. It is demonstrated how to quantize favorable and
unfavorable qualitative facts so that they can be stored and processed
efficiently, as well as how to use the reliability of the contributing
sources in our decision makings. The concept of a confidence index set
(ciset), is introduced in order to mathematically model the above
issues. A simple introduction to relational database systems is given
allowing anyone with no background in database theory to appreciate the
further contents of this work, especially the extended relational
operations and semantics of the ciset relational database model.