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Encyclopedia of Database Systems pp 547–548Cite as

Daplex

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Definition

Daplex is a query language based on a functional data model [1] with the same name. The Daplex data model represents data in terms of entities and functions. The Daplex data model is close to the entity-relationship (ER) model with the difference that relationships between entities in Daplex have a logical direction, whereas ER relationships are directionless. Unlike ER entities, relationships, and properties are all represented as functions in Daplex. Also, entity types are defined as functions without arguments returning sets of a built-in type ENTITY. The entity types are organized in a type/subtype hierarchy. Functions represent properties of entities and relationships among entities. Functions also represent derived information. Functions may be set-valued and are invertible. The database is represented as tabulated function extents. Database updates change the function extents.

The Daplex query language has been very influential for many other query languages, both...

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Recommended Reading

  1. P.M.D., Gray L., Kerschberg P.J.H., and King A. (eds.). Poulovassilis The Functional Approach to Data Management. Springer, Berlin, 2004.

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  2. Landers T. and Rosenberg R.L. An overview of Multibase. In Proc. 2nd Int. Symp. on Distributed Databases, 1982, pp. 153–184.

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  3. Shipman D.W. The functional data model and the data language DAPLEX. ACM Trans. Database Syst., 6(1):140–173, 1981.

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Author information

Authors and Affiliations

  1. Uppsala University, Uppsala, Sweden

    Tore Risch

Authors
  1. Tore Risch
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Editor information

Editors and Affiliations

  1. College of Computing, Georgia Institute of Technology, 266 Ferst Drive, 30332-0765, Atlanta, GA, USA

    LING LIU (Professor) (Professor)

  2. Database Research Group David R. Cheriton School of Computer Science, University of Waterloo, 200 University Avenue West, N2L 3G1, Waterloo, ON, Canada

    M. TAMER ÖZSU (Professor and Director, University Research Chair) (Professor and Director, University Research Chair)

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© 2009 Springer Science+Business Media, LLC

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Risch, T. (2009). Daplex. In: LIU, L., ÖZSU, M.T. (eds) Encyclopedia of Database Systems. Springer, Boston, MA. https://doi.org/10.1007/978-0-387-39940-9_1107

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