Problems with OOFNF: a proposed normal form for object oriented databases


Authors: Gillian Dobbie, Peter Andreae
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Update anomolies arise in relational databases if the database schema is poorly designed. Normal forms that have been defined over relational database schemas disallow redundant data in the resulting database. Without redundancy, update anomolies don't occur. Update anomalies can also arise in object oriented databases if the schema is poorly designed. Several definitions of normal forms over object oriented databases have been proposed.
We are particularly interested in object oriented functional normal form (OOFNF) . While the intuition behind OOFNF is good, the details of the definition are wrong. For example, the definition of OOFNF is based on the concept of path functional dependencies (PFD) that have been defined over single valued properti es. The authors of the paper defining OOFNF neither extend the definition of PFDs to multi-valued properties, nor do they restrict their own data model to single valued prpoperties.
In this paper, we redefine OOFNF over a restricted data model with single valued properties.

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