Join dependencies can be divided into cyclic and acyclic join dependencies. A fundamental result in dependency theory is that a join dependency is acyclic if and only if it is equivalent to a set of MVDs. In ad
multivalued dependencyjoin dependencythird normal formfourth normal formfifth normal formthe entity-relationship approachIn this paper, we show that multivalued dependencies and join dependencies are not very viable for certain cases of relational database design; they are sometimes difficult to be ...
A multivalued dependency X Y is a special case of a join dependency expressed as [ XY , X ( U XY )], which specifies that the decomposition of any instance I satisfying [ XY , X ( U XY )] into π XY ( I ) and π X ( U XY ) ( I ) is lossless, i.e., I = π XY ...
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the foundation of computers and Database Design.The key points in these slide are:Multivalued Dependencies, Functional Dependency, Domain and Range, Set of Possible Values, Full Constraint, Sets of Attributes, Tuple-Generating Dependency, Embedded Constraint, Lossless-Join Decomposition, Split of ...
a) Functional dependency b) Multivalued dependency c) Join dependency d) Domain-key View Answer 10. In 2NF a) No functional dependencies (FDs) exist b) No multivalued dependencies (MVDs) exist c) No partial FDs exist d) No partial MVDs exist ...
While this definition is fine for FDs in relations, it doesn't gener- alise in an obvious way to other classes of relational integrity constraints, such as multi-valued dependencies (MVDs) or join dependencies (JDs) or inclusion dependencies (INDs), nor to other data models. The key to ...
<dependency><groupId>org.apache.commons</groupId><artifactId>commons-collections4</artifactId><version>4.5.0-M2</version></dependency>Copy 3. Adding Elements into aMultiValuedMap We can add elements using theputandputAllmethods. Let’s start by creating an instance ofMultiValuedMap: ...
2) multivalued dependency(MVD) 多值依赖 1. the definition of preserve multivalued dependency(MVD),alg orithm of preserve multivalued dependency set,algorithm of generated m ultivalued dependency set and algorithm of join tree was presented and provied base on data dependency. ...
2) fuzzy null value embedded multivalued dependency 模糊空值嵌入多值依赖3) Fuzzy Null value Embedded Join Dependency 模糊空值嵌入连接依赖4) fuzzy multivalued dependency 模糊多值依赖 1. This paper discusses the quality of fuzzy multivalued dependency. 本文探讨了模糊多值依赖的性质,对单一模糊多...