Indian Journal of Science and Technology
Year: 2015, Volume: 8, Issue: 35, Pages: 1-10
Samad Najjar Ghabel and Saeid Pashazadeh*
Faculty of Electrical and Computer Engineering, University of Tabriz, Tabriz, Iran;
[email protected], [email protected]
Functional Dependency (FD) rules arise from applications semantic and enforcing integrity of minimal cover of FDs by normalization or triggers is sufficient condition for guaranteeing integrity of database. Formal achievement of minimal and optimal FDs from initial FDs is accomplished in this paper. Process of computing optimal and minimal FDs is presented and modeled by Colored Petri Net(CPN). Proposed model iteratively applies a subset of Armstrong’s axioms and infers FDs that are origin of all other FDs. Execution of model automatically is stopped when markings of model’s places do not change in iteration. Minimal and optimal FDs are automatically computed and stored in two different places of the model. Although CPN is used in many areas but modeling automatic generation of optimal and minimal cover set using CPN is a novel work. Proposed CPN model in this paper can be considered as automatic proof generator too. Model is designed such that state space graph of model is very small and is generated quickly. Colour sets are declared such that starting from initial markings, step by step proof of inferring optimal and minimal cover FDs can be extracted automatically. Proposed model can be used as a simple tool for automatically computing optimal and minimal FDs of a set of initial FDs.
Keywords: Coloured Petri Net, Functional Dependency, Modeling, Optimal Cover, Verification
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