Analysis of Typed Inclusion Dependencies with Null Values
نویسندگان
چکیده
منابع مشابه
Null Inclusion Dependencies in Relational Databases
Functional dependencies (FDs) and inclusion dependencies (INDs) are the most fundamental integrity constraints that arise in practice in relational databases. We introduce null inclusion dependencies (NINDs) to cater for the situation when a database is incomplete and contains null values. We show that the implication problem for NINDs is the same as that for INDs. We then present a sound and c...
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Database relations with incomplete information are considered. The no-information interpretation of null values is adopted, due to its characteristics of generality and naturalness. Coherently with the framework and its motivation, two meaningful classes of integrity constraints are studied: (a) functional dependencies, which have been widely investigated in the classical relational theory and ...
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Functional dependencies are an integral part of database design. However, they are only defined when we exclude null markers. Yet we commonly use null markers in practice. To bridge this gap between theory and practice, researchers have proposed definitions of functional dependencies over relations with null markers. Though sound, these definitions lack some qualities that we find desirable. Fo...
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ژورنال
عنوان ژورنال: Modeling and Analysis of Information Systems
سال: 2017
ISSN: 2313-5417,1818-1015
DOI: 10.18255/1818-1015-2017-2-155-167