Abstract
When a set of rules generates (conflicting) values for a virtual attribute of some tuple, the system must resolve the inconsistency and decide on a unique value that is assigned to that attribute. In most current systems, the conflict is resolved based on criteria that choose one of the rules in the conflicting set and use the value that it generated. There are several applications, however, where inconsistencies of the above form arise, whose semantics demand a different form of resolution. We propose a general framework for the study of the conflict resolution problem, and suggest a variety of resolution criteria, which collectively subsume all previously known solutions. With several new criteria being introduced, the semantics of several applications are captured more accurately than in the past. We discuss how conflict resolution criteria can be specified at the schema or the rule-module level. Finally, we suggest some implementation techniques based on rule indexing, which allow conflicts to be resolved efficiently at compile time, so that at run time only a single rule is processed.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Aho, A., Sagiv, Y., and Ullman, J. (1979). Equivalences among Relations Expressions.SIAM Journal on Computing, 8, 218–246.
Aho, A. and Ullman, J. (1979). Universality of data retrieval languages.Proc. 6th ACM Symp. Principles of Programming Languages (pp. 110–117). San Antonio, TX.
Blair, H.A. and Subrahmanian, V.S. (1989) Paraconsistent Logic Programming.Theoretical Computer Science, 68, 135–154.
Borgida, A. (1985). Language Features for Flexible Handling of Exceptions in Information Systems.ACM Transactions on Database Systems, 10, 107–131.
Borgida, A. (1988). Modeling class hierarchies with contradictions.Proc. 1988 ACM-SIGMOD Conf. Management of Data (pp. 434–443). Chicago, IL.
Chandra, A.K. and Merlin, P.M. (1977). Optimal implementation of conjunctive queries in relational data bases.Proc. 9th Ann. ACM Symp. Theory of Computing (pp. 77–90). Boulder, CO.
Forgy, C.L. (1979). On the Efficient Implementation of Production Systems. Ph.D. dissertation, Carnegie-Mellon University, Department of Computer Science.
Hanson, E. (1992). Rule testing and execution in Ariel.Proc. 1992 ACM-SIGMOD Conf. Management of Data (pp. 49–58). San Diego, CA.
Ioannidis, Y. and Sellis, T. (1989). Conflict resolution of rules assigning values to virtual attributes.Proc. 1989 ACM-SIGMOD Conf. Management of Data (pp. 205–214). Portland, OR.
Kifer, M. and Lozinskii, E. (1989). RI: A logic for reasoning with inconsistency.Proc. 4th Symp. Logic in Computer Science (pp. 253–262). Cambridge, MA.
Kung, R-M., Hanson, E., Ioannidis, Y., Sellis, T., Shapiro, L., and Stonebraker, M. (1986). Heuristic Search in Data Base Systems. In L. Kerschberg (Ed.),Expert Database Systems, Proceedings from the First International Workshop, (pp. 537–548). Menlo Park, CA: Benjamin/Cummings.
Nicolas, J.M. and Gallaire, H. (1978). Data Base: Theory vs. Interpretation. In H. Gallaire and J. Minker (Eds.),Logic and Data Bases (pp. 33–54). New York: Plenum Press.
Sellis, T. and Lin, C-C. (1992). A Geometric Approach to Indexing Large Rule Bases. In A. Pirotte, C. Delobel, and G. Gottlob (Eds.),Advances in Database Technology — EDBT'92, (pp. 405–420). Berlin: Springer-Verlag.
Sellis, T., Roussopoulos, N., and Faloutsos, C. (1987). The R+-tree: A dynamic index for multidimensional objects.Proc. 13th Int. VLDB Conf. (pp. 507–518). Brighton, England.
Shortliffe, E.H. (1976).Computer-Based Medical Consultations: MYCIN. New York: Elsevier.
Stonebraker, M., Hanson, E., and Potamianos, S. (1988). The Postgres Rule Manager.IEEE Transactions on Software Engineering, 14, 897–907.
Stonebraker, M. and Rowe, L. (1986). The design of Postgres.Proc. 1986 ACM-SIGMOD Conf. Management of Data, (pp. 340–355). Washington, DC.
Stonebraker, M., Sellis, T., and Hanson, E. (1987). An Analysis of Rule Indexing Implementations in Data Base Systems. In L. Kerschberg (Ed.),Expert Database Systems, Proc. from the First International Conference, (pp. 465–476). Menlo Park, CA: Benjamin/Cummings.
Tarski, A. (1955). A Lattice Theoretical Fixpoint Theorem and Its Applications.Pacific Journal of Mathematics, 5, 285–309.
VanEmden, M.H. and Kowalski, R.A. (1976). The Semantics of Predicate Logic as a Programming Language.Journal of the ACM 23, 733–742.
Widom, J., Cochrane R.J., and Lindsay, B.G. (1991). Implementing set-oriented production rules as an extension to Starburst.Proc. 17th VLDB Conf., (pp. 275–285). Barcelona, Spain.
Author information
Authors and Affiliations
Additional information
An earlier version of this work appeared under the title “Conflict Resolution of Rules Assigning Values to Virtual Attributes” inProceedings of the 1989 ACM-Sigmod Conference, Portland, OR, June 1989, pp. 205–214.
Partially supported by the National Science Foundation under Grant IRI-9157368 (PYI Award) and by grants from DEC, HP, and AT&T.
Partially supported by the National Science Foundation under Grant IRI-9057573 (PYI Award), IBM, DEC, and the University of Maryland Institute for Advanced Computer Studies (UMIACS).
Rights and permissions
About this article
Cite this article
Ioannidis, Y.E., Sellis, T.K. Supporting inconsistent rules in database systems. J Intell Inf Syst 1, 243–270 (1992). https://doi.org/10.1007/BF00962920
Issue Date:
DOI: https://doi.org/10.1007/BF00962920