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System R: A Relational Data Base Management System Disclosure Number: IPCOM000131393D
Original Publication Date: 1979-May-01
Included in the Prior Art Database: 2005-Nov-10
Document File: 10 page(s) / 38K

Publishing Venue

Software Patent Institute

Related People

M. M. Astrahan: AUTHOR [+20]


IBM San Jose Research Laboratory

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This record contains textual material that is copyright ©; 1979 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Contact the IEEE Computer Society (714-821-8380) for copies of the complete work that was the source of this textual material and for all use beyond that as a record from the SPI Database.

System R: A Relational Data Base Management System

M. M. Astrahan

M. W. Blasgen

D. D. Chamberlin , J. N. Gray , W. F. King , B. G. Lindsay , R. A. Lorie , J. W. Mehl , T. G. Price , G. R. Putzolu , M. Schkolnick , P. P. Selinger , D. R. Slutz , H. R. Strong , P. Tiberio , I. L. Traiger , B. W. Wade , R. A. Yost

IBM San Jose Research Laboratory

(Image Omitted: A relational approach makes this experimental data base management system unusually easy to install and use. Some of the decisions made in System R design in order to enhance usability also offer major bonuses in other areas.)

Perhaps the greatest impediments to the use of a computerized data base management system are installation cost and complexity. At present, installation of these systems requires a staff skilled in telecommunications, operating systems, data management and in applications. In response, our lab designed and implemented System R -- an experimental data base management system allowing easy definition of data bases and data base applications without sacrificing the function and performance available in most commercial systems. Among its capabilities, the system provides a sophisticated authorization facility, and automatically handles system functions such as recovery and concurrency control. System R adopts a relational data model and supports a language called SQL for defining, accessing, and modifying various views of the data base.

The relational data model

All data base management systems represent data in the form of records. Records, the basic unit of storage, contain fields, which hold values. Each record represents some fact about the world. A telephone record, for example, has three fields: name, address, and telephone number. Each realworld instance of the record assigns a value to each field.

Data base management systems differ in the way they organize records. System R organizes data into tables -- sequences of identically formatted records. Train schedules, price lists, tide tables, and phone books all fit this model.

A relational model was adopted because it is easy to understand and to explain and because it lends itself to powerful relational operators Such as sort, join, project, and selectly By relational model, we mean an organization which collects data into just such uniform tables as those discussed above, and which allows a user to access data without having to specify the physical organization of the tables. Figure 1 shows a fragment of a relational data base; the various attributes -- name, office, job, salary --...