A Relational Model of Data for Large Shared Data Banks

  • E. F. Codd


Future users of large data banks must be protected from having to know how the data is organized in the machine (the internal representation). A prompting service which supplies such information is not a satisfactory solution. Activities of users at terminals and most application programs should remain unaffected when the internal representation of data is changed and even when some aspects of the external representation are changed. Changes in data representation will often be needed as a result of changes in query, update, and report traffic and natural growth in the types of stored information.

Key Words and Phrases

data bank data base data structure data organization hierarchies of data networks of data relations derivability redundancy consistency composition join retrieval language predicate calculus security data integrity 

CR Categories

3.70 3.73 3.75 4.20 4.22 4.29 


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Copyright information

© Springer-Verlag Berlin Heidelberg 2002

Authors and Affiliations

  • E. F. Codd
    • 1
  1. 1.IBM Research LaboratorySan JoseUSA

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