Nets in data bases
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Up to the present, contributions of General Net Theory to the field of database research and development are restricted to a few selected topics which, however, are of central concern. Two particular areas shall be addressed here: access synchronization and conceptual schema.
Access synchronization deals with the question of how to organize the accesses of users at different sites to a distributed database such that deadlocks and database inconsistencies can be avoided or detected and remedied. The use of PrT-nets to model such an access protocol is demonstrated. It is shown how formal algebraic methods can be applied to prove essential properties of the specified access protocol.
The conceptual schema is intended to be a formally modelled information system that contains exactly all knowledge about those invariant properties of the real system in mind which are regarded as relevant in the given context and form the starting point for a database design process. This includes static and dynamic constraints. The principles of modelling conceptual schemas with nets and of an integrated treatment of static and dynamic aspects shall be exemplified.
KeywordsData Item Conceptual Schema Concurrency Control Read Request Database Theory
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- [DGS85]Davidson, S.B., Garcia-Molina, H., Skeen, D.: Consistency in Partitioned Networks. ACM Computing Surveys, Vol. 17, No. 3, Sept. 1985, 341–370.Google Scholar
- [Du84]Durchholz, R.: Konzeptionelles Schema. Informatik-Spektrum Vol. 7, No. 4, Nov. 1984, 245–247.Google Scholar
- [GL78]Genrich, H.J., Lautenbach, K.: Facts in Place/Transition-Nets. Math. Foundations of Computer Science 1978. Lecture Notes in Computer Science 64, Springer-Verlag, 1978.Google Scholar
- [GL81]Genrich, H.J., Lautenbach, K.: System Modelling with High-level Petri Nets. Theoretical Computer Science 13, 1981, 109–136.Google Scholar
- [HR85]Heuser, C.A., Richter, G.: On the Relationship between Conceptual Schemata and Integrity Constraints on Databases. In Meersman, R., Steel, T.B. (eds.): Proc. of the IFIP Working Conference on Database Semantics, North-Holland, Amsterdam, 1986.Google Scholar
- [ISO82]ISO TC97/SC5/WG3: Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. no. ISO/TC97/SC5-N695, March 15, 1982.Google Scholar
- [Ri83]Richter, G.: Netzmodelle für die Bürokommunikation. Informatik-Spektrum, Vol. 6, No. 4, 1983, 210–220 (part 1) and Vol. 7, No. 1, 1984, 28–40 (part 2).Google Scholar
- [TK78]Tsichritzis, D., Klug, A.: The ANSI/X3/SPARC DBMS Framework. Report of the Study Group on Data Base Management Systems. Information Systems, Vol. 3, No. 3, 1978, 173–191.Google Scholar
- [Ul85]Ullman, J.D.: Principles of Database Systems. 2nd edition, Computer Science Press, Rockville, Md., 1985.Google Scholar
- [Vo80]Voss, K.: Using Predicate/Transition-Nets to Model and Analyze Distributed Database Systems. IEEE Trans. Software Eng., Vol. SE-6, Nov. 1980, 539–544.Google Scholar
- [Vo82]Voss, K.: Nets as a Consistent Formal Tool for the Stepwise Design and Verification of a Distributed System. In Hawgood, J. (ed.): Evolutionary Information Systems. North-Holland Publ. Comp., Amsterdam, 1982, 173–191.Google Scholar