Fundamentals of order dependencies
نویسندگان
چکیده
منابع مشابه
Fundamentals of Order Dependencies
Dependencies have played a significant role in database design for many years. They have also been shown to be useful in query optimization. In this paper, we discuss dependencies between lexicographically ordered sets of tuples. We introduce formally the concept of and present a set of axioms (inference rules) for them. We show how query rewrites based on these axioms can be used for query opt...
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Dependencies have played a significant role in database design for many years. They have also been shown to be useful in query optimization. In this paper, we discuss the new type of dependency for polarized lexicographically ordered sets of tuples. We introduce formally the concept of polarized order dependencies (PODs). We discuss their potential significance for database systems, and present...
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We prove that the expressive power of first-order logic with team semantics plus contradictory negation does not rise beyond that of first-order logic (with respect to sentences), and that the totality atoms of arity k + 1 are not definable in terms of the totality atoms of arity k. We furthermore prove that all first-order nullary and unary dependencies are strongly first order, in the sense t...
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Dependencies play an important role in database theory. We study order dependencies (ODs) and unidirectional order dependencies (UODs), which describe the relationships among lexicographical orderings of sets of tuples. We investigate the axiomatization problem for order
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Dependencies play an important role in databases. We study order dependencies (ODs)—and unidirectional order dependencies (UODs), a proper sub-class of ODs—which describe the relationships among lexicographical orderings of sets of tuples. We consider lexicographical ordering, as by the order-by operator in SQL, because this is the notion of order used in SQL and within query optimization. Our ...
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ژورنال
عنوان ژورنال: Proceedings of the VLDB Endowment
سال: 2012
ISSN: 2150-8097
DOI: 10.14778/2350229.2350241