- functional dependency
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A constraint between two sets of attributes in a relation.
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functional dependency
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Functional dependency — A functional dependency (FD) is a constraint between two sets of attributes in a relation from a database.Given a relation R , a set of attributes X in R is said to functionally determine another attribute Y , also in R , (written X → Y ) if and… … Wikipedia
trivial functional dependency — noun A functional dependency of an attribute on a superset of itself … Wiktionary
Dependency — or dependent may refer to: Contents 1 Sciences 1.1 Computer science 1.2 Economics 1.3 Linguistics 1.4 … Wikipedia
Dependency grammar — Hybrid constituency/dependency tree from the Quranic Arabic Corpus Dependency grammar (DG) is a class of syntactic theories developed by Lucien Tesnière. It is distinct from phrase structure grammars, as it lacks phrasal nodes. Structure is… … Wikipedia
Dependency (UML) — A dependency in the Unified Modeling Language exists between two defined elements if a change to the definition of one may result in a change to the other. In UML this is indicated by a dashed line pointing from the dependent (or client) to the… … Wikipedia
Functional decomposition — refers broadly to the process of resolving a functional relationship into its constituent parts in such a way that the original function can be reconstructed (i.e., recomposed) from those parts by function composition. In general, this process of … Wikipedia
Dependency theory (database theory) — Dependency theory is a subfield of database theory which studies implication and optimization problems related to logical constraints, commonly called dependencies, on databases. The best known class of such dependencies are functional… … Wikipedia
Functional programming — In computer science, functional programming is a programming paradigm that treats computation as the evaluation of mathematical functions and avoids state and mutable data. It emphasizes the application of functions, in contrast with the… … Wikipedia
Dependency diagram — A dependency diagram is a visual representation of a dependency graph. Dependency diagrams are integral to software development, outlining the complex, interrelationships of various functional elements. Typically in a dependency diagram, arrows… … Wikipedia
Transitive dependency — In mathematics, a transitive dependency is a functional dependency which holds by virtue of transitivity. A transitive dependency can occur only in a relation that has three or more attributes. Let A, B, and C designate three distinct attributes… … Wikipedia
