How did relational databases evolve? This paper presents an overview of System R, a pioneering database management system designed with a high-level relational data interface. System R prioritized data independence, isolating users from underlying storage structures and enabling them to define diverse relational views on shared data. The system offered a range of data control features, including authorization, integrity assertions, triggered transactions, and a logging and recovery subsystem. These features were aimed at maintaining data consistency, especially in shared-update environments. System R's architecture and design provided a framework for managing relational data, and served as a research tool for database architecture. While the system was under implementation and evaluation at the time of this paper, the design principles and functionalities of System R laid the groundwork for subsequent advancements in database management. It remains a significant milestone in the evolution of database technology.
Published in ACM Transactions on Database Systems, this paper fits squarely within the journal's focus on database architecture and design. System R was a pivotal research system that greatly contributed to the evolution of relational database technology and the field of computer science.