Principles of Data Base Systems
Jeffrey David Ullman · Cumulative Index of Computer Aided Architectural Design · 1980
A large part is a description of relations, their algebra and calculus, and the query languages that have been designed using these concepts. There are explanations of how the theory can be used to design good systems. A description of the optimization of queries in relation-based query languages is provided, and a chapter is devoted to the recently developed protocols for guaranteeing consistency in databases that are operated on by many processes concurrently