LPIS Home Page
Google Search

Title: Constraint Maintenance Using Generated Methods in the P/FDM Object-Oriented Database
Author(s): S. Embury, P. Gray, N. Bassiliades.
Availability: Click here to download the GZ (gzipped postscript) file (17 pages).
Keywords: Semantic Integrity Constraints, Object-Oriented Databases, Functional Data Model, Constraint Compilation, Incremental Constraint Checking, Meta-Data.
Appeared in: Proc. 1st International Workshop on Rules in Database Systems, N.W. Paton and M.H. Williams (Eds.), Springer-Verlag, pp. 364-381, Edinburgh, Scotland, 30 August- 1 September 1993, 1994.
Abstract: We discuss the use of code-generated methods in Prolog as a flexible and efficient way to implement complex semantic constraints in an OODB. We introduce a high-level constraint language CoLan, based on functions and sets and including range quantifiers, from which fragments of code are generated to check the constraints. These fragments are attached to slots in class descriptors, and are also inherited (constraints cannot be overridden). Thus many fragments can come from one constraint and one slot may have attached fragments from many constraints. Constraints can be selectively disabled or removed which causes inhibition or disabling of corresponding fragments. This overcomes many objections to implementing constraints through methods. We have prototyped it by using the metaclass facilities of ADAM to initiate code generation. We are now re-implementing it in P/FDM, using changes to metadata (P/FDM does not have full metaclasses). This will incorporate a transaction mechanism and also provide queries on constraints. This approach opens a number of interesting future directions.
See also : CoLan

        This paper has been cited by the following:

1 U. Jaeger, J. C. Freytag, "An Annotated Bibliography on Active Databases", ACM SIGMOD Records, Vol.24, No.1, March 1995, pp. 58-69.
2 S. Pulkowski, "Entwicklung eines Kernels für parametrisierte Regelsemantiken in Kheops", Diplomarbeit, Institut für Programmstrukturen und Datenorganisation, Universität Karlsruhe, 1997.
3 Opher Etzion, Boris Dahav, "Patterns of self-stabilization in database consistency maintenance", Data and Knowledge Engineering, 28 (1998), 299319.
4 H. Oakasha, S. Conrad, G. Saake, "Consistency Management in Object-Oriented Databases", ECOOP Workshop on Object-Oriented Databases, pp. 97-108, 1999.
5 H. Oakasha, "Consistency Management for Object Databases", Ph.D. thesis, Informatics Faculty, University of Magdeburg, Germany, 2000.
6 Philippe Collet, "Fiabilité des systèmes à objets persistants: les assertions persistent", Lobjet 7/2001. LMO2001, p. 117-132.
7 H. Oakasha, S. Conrad, G. Saake, "Consistency management in object-oriented databases", Concurrency and Computation: Practice and Experience, Vol. 13, No. 11, 2001, pp. 955985.
8 Hamidah Ibrahim, Checking Integrity Constraints in a Distributed Database, in Encyclopedia of Database Technologies and Applications, Laura Rivero, Jorge Doom, Viviana Ferraggine, Eds., pp. 66-73, Idea Group Reference, 2006.