Evidence grows that ORM has some problems to overcome in order to escape the charge that it cannot reliably lead, as claimed, to ONF (optimal normal form) relational schemas. Some of that evidence we present here. We also indicate that there is more than one way to address the issue effectively, thus saving ORM’s reputation as a generator of fully normalized relational schemas. But of two ways mentioned, the more satisfactory one involves, essentially, ascribing a certain semantics to the idea of “role-playing” in ORM. We show how it would address these issues, and why it is the better approach.


Relational Schema Definite Description Data Redundancy Fact Type Reference Scheme 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Carver, A.: How To Avoid Redundant Object-References. In: Meersman, R., Herrero, P. (eds.) OTM-WS 2008. LNCS, vol. 5333, pp. 770–779. Springer, Heidelberg (2008)CrossRefGoogle Scholar
  2. 2.
    Carver, A., Halpin, T.: Atomicity and Semantic Normalization. International Journal of Information System Modeling and Design 1(2), 23–39 (2010)CrossRefGoogle Scholar
  3. 3.
    Halpin, T.: What is an Elementary Fact? In: Nijssen, G.M., Sharp, J. (eds.) Proc. 1st NIAM-ISDM Conf. (1993)Google Scholar
  4. 4.
    Halpin, T., Carver, A., Owen, K.M.: Reduction Transformations in ORM. In: Meersman, R., Herrero, P. (eds.) OTM-WS 2007, Part I. LNCS, vol. 4805, pp. 699–708. Springer, Heidelberg (2007)CrossRefGoogle Scholar
  5. 5.
    Halpin, T., Morgan, T.: Information Modeling and Relational Databases, 2nd edn. Morgan Kaufmann Publishers, San Francisco (2008)Google Scholar
  6. 6.
    Levinson, S.C.: Pragmatics. Cambridge University Press, Cambridge (1983)Google Scholar
  7. 7.
    Lyons, J.: Semantics, vol. 2. Cambridge University Press, Cambridge (1977)CrossRefGoogle Scholar
  8. 8.
    The World Wide Web Consortium: XQuery 1.0 and XPath 2.0 Formal Semantics,

Copyright information

© Springer-Verlag Berlin Heidelberg 2011

Authors and Affiliations

  • Andy Carver
    • 1
  1. 1.INTI International UniversityMalaysia

Personalised recommendations