Representing imprecise information in NF/sup 2/ relations

A model which can represent imprecise information and store it as an extension of normal-form (NF/sup 2/) relations with one level of nesting is proposed. It is shown by example that the model is more general than the ordinary NF/sup 2/ relational model. This generality is accomplished by an operator that can manipulate imprecise data and precise data and can have the same properties as the nest and the pack operators defined for NF/sup 2/ relations. This operator, called the merge operator, is defined. A representation framework for representing incomplete data, including range values and various null values, is also proposed.<
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