Axiomatisation of functional dependencies in incomplete relations
نویسندگان
چکیده
منابع مشابه
Axiomatisation of Functional Dependencies in Incomplete Relations
Incomplete relations are relations which contain null values, whose meaning is \value is at present unknown". Such relations give rise to two types of functional dependency (FD). The rst type, called the strong FD (SFD), is satissed in an incomplete relation if for all possible worlds of this relation the FD is satissed in the standard way. The second type, called the weak FD (WFD), is satissed...
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ژورنال
عنوان ژورنال: Theoretical Computer Science
سال: 1998
ISSN: 0304-3975
DOI: 10.1016/s0304-3975(98)80029-7