Key extensions of abstract data types, final algebras, and database semantics

  • H. -D. Ehrich
Part II Research Contributions Section 2: Specification
Part of the Lecture Notes in Computer Science book series (LNCS, volume 240)

Abstract

The algebraic specification of abstract data types provides a number of features for structuring specifications in order to make them easier to write, to read, to understand, and to maintain. Among the most important such features are different kinds of extensions, based on initial, final, or behavioural semantics. This paper studies a new kind of extension called key extension, and its final algebra semantics. Key extensions model one of the essential steps in database specification where abstract object types are to be specified on the basis of given abstract data types. The intended standard semantics is a universe of "possible objects" that provides the basis for further database concepts like situations, states, etc. It is shown under which conditions final algebras exist that can serve as a natural standard semantics for key extensions. We also characterize rather a large class of constraints that can be used for keys in accordance with our semantics.

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References

  1. DMW82.
    Dosch,W./Mascari,G./Wirsing, M.: On the Algebraic Specification of Databases. Proc. 8th Int. Conf. on Very Large Data Bases, Mexico City 1982Google Scholar
  2. Eh78.
    Ehrich, H.-D.: Extensions and Implementations of abstract data type specifications. Proc. 7th Symp. MFCS 78 (J. Winkowski, ed.). LNCS 64, Springer-Verlag, Berlin 1978, 155–164Google Scholar
  3. Eh82.
    Ehrich, H.-D.: On the theory of specification, implementation and parameterization of abstract data types. Journal ACM 29 (1982), 206–227Google Scholar
  4. Eh84.
    Ehrich,H.-D.: Algebraic (?) Specification of Conceptual Database Schemata (Extended Abstract). Proc. 3rd Workshop on Theory and Application of Abstract Data Types (H.-J.Kreowski, ed.) (To appear as Informatik-Fachbericht, Springer-Verlag)Google Scholar
  5. EKW78.
    Ehrig,H./Kreowski,H.-J./Weber,H.: Algebraic Specification Schemes for Database Systems. Proc 4th Int. Conf. on Very Large Databases, Berlin 1978Google Scholar
  6. ELG84.
    Ehrich,H.-D./Lipeck,U.W./Gogolla,M.: Specification, Semantics, and Enforcement of Dynamic Database Constraints. Proc. 10th Int. Conf. on Very Large Databases, Singapore 1984Google Scholar
  7. EM85.
    Ehrig, H./Mahr, B.: Fundamentals of Algebraic Specification 1. Springer-Verlag, Berlin 1985Google Scholar
  8. GMS83.
    Golshani,F./Maibaum,T.S.E./Sadler,M.R.: A Modal System of Algebras for Database Specification and Query/Update Language Support. Proc. 9th Int. Conf. on Very Large Data Bases, Florence 1983Google Scholar
  9. GTW78.
    Goguen, J.A./Thatcher, J.W./Wagner, E.G.: An initial algebra approach to the specification, correctness and implementation of abstract data types. Current Trends in Programming Methodology IV (R.T. Yeh, ed.), Prentice-Hall, Englewood Cliffs 1978, 80–149Google Scholar
  10. Go85.
    Gogolla,M.: A Final Algebra Semantics for Errors and Exceptions. Proc. 3rd Workshop on Theory and Application of Abstract Data Types (H.-J.Kreowski, ed.). (To appear as Informatik-Fachbericht, Springer-Verlag)Google Scholar
  11. HR83.
    Hupbach, U.L./Reichel, H.: On Behavioural Equivalence of Data Types, EIK 19 (1983), 297–305Google Scholar
  12. Ja85.
    Jantke,K.: The Recursive Power of Algebraic Semantics (submitted for publication)Google Scholar
  13. KMS85.
    Khosla, S./Maibaum, T.S.E./Sadler, M.: Database Specification. Proc. IFIP Working Conf.on Database Semantics (R. Meersman/T.B. Steel, eds.), North Holland, Amsterdam 1985Google Scholar
  14. LEG85.
    Lipeck, U.W./Ehrich, H.-D./Gogolla, M.: Specifying Admissibility of Dynamic Database Behaviour Using Temporal Logic. Proc. IFIP Working Conf. on Theoretical and Formal Aspects of Information Systems (A Sernadas et al., eds), North Holland, Amsterdam 1985Google Scholar
  15. Li85.
    Lipeck,U.W.: Stepwise Specification of Dynamic Database Behaviour. (To appear)Google Scholar
  16. LSE85.
    Lipeck, U.W./Saake,G./Ehrich,H.-D.: Monitoring Dynamic Integrity Constraints by Transition Graphs (submitted for publication)Google Scholar
  17. Sa85.
    Saake,G.: Konstruktion von Transitionsgraphen aus temporalen Formeln zur Integritätsüberprüfung in Datenbanken. Diploma Thesis, Techn. Univ. Braunschweig 1985Google Scholar
  18. Wa79.
    Wand, M.: Final Algebra Semantics and Data Type Extensions. Journal of Computer and System Sciences 19 (1979), 27–44Google Scholar

Copyright information

© Springer-Verlag 1986

Authors and Affiliations

  • H. -D. Ehrich
    • 1
  1. 1.Inst. f. Informatik, TU BraunschweigBraunschweigWest Germany

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