Encyclopedia of Database Systems

2009 Edition

System R (R*) Optimizer

  • Mouna Kacimi
  • Thomas Neumann
Reference work entry
DOI: https://doi.org/10.1007/978-0-387-39940-9_384


The System R Optimizer is the cost-based query optimizer of System R. It pioneered several optimization techniques, including using dynamic programming for bottom-up join tree construction, and the concept of interesting orderings for exploiting ordering in intermediate results. Later, it was generalized for distributed database systems in System R*.

Historical Background

System R is a database management system based on a relational data model that was proposed by E. F. Codd [4] in 1970. The system offers data independence by providing a high-level user interface through which the end user deals with data content rather than the underlying storage structures. In other words, users do not need to know how the tuples are physically stored and which access paths are available to write queries. Thus, data storage structures may change over time without users being aware of it, providing a high level of data independence and user productivity. Moreover, System R offers...

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Recommended Reading

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    Astrahan M.M., Blasgen M.W., Chamberlin D.D., Eswaran K.P., Gray J., Griffiths P.P., III W.F.K., Lorie R.A., McJones P.R., Mehl J.W., Putzolu G.R., Traiger I.L., Wade B.W., and Watson V. System R: Relational approach to database management. ACM Trans. Database Syst., 1(2):97–137, 1979.Google Scholar
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    Chamberlin D.D., Astrahan M.M., Blasgen M.W., Gray J., III W.F.K., Lindsay B.G., Lorie R.A., Mehl J.W., Price T.G., Putzolu G.R., Selinger P.G., Schkolnick M., Slutz D.R., Traiger I.L., Wade B.W., and Yost R.A. A history and evaluation of system R. Commun. ACM, 24(10):632–646, 1981.Google Scholar
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    Chamberlin D.D. and Boyce R.F. SEQUEL: A Structured English Query Language. In Proc. SIGMOD Workshop, Vol. 1. 1974, pp. 249–264.Google Scholar
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    Codd E.F. A relational model of data for large shared data banks. Commun. ACM, 13(6):377–387, 1970.Google Scholar
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    Gray J. Notes on data base operating systems. In Advanced Course: Operating Systems, 1978, pp. 393–481.Google Scholar
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    Lohman G.M., Mohan C., Haas L.M., Daniels D., Lindsay B.G., Selinger P.G., and Wilms P.F. Query processing in R*. In Query Processing in Database Systems, Springer, 1985, pp. 31–47.Google Scholar
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    Lorie R.A. and Nilsson J.F. An access specification language for a relational data base system. IBM J. Res. Dev., 23(3):286, 1979.zbMATHGoogle Scholar
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    Selinger P.G., Astrahan M.M., Chamberlin D.D., Lorie R.A., and Price T.G. Access path selection in a relational database management system. In Proc. ACM SIGMOD Int. Conf. on Management of Data, 1979, pp. 23–34.Google Scholar

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  • Mouna Kacimi
    • 1
  • Thomas Neumann
    • 1
  1. 1.Max-Planck Institute for Informatics, Saarbrücken Germany