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Question
Describe the use of null values in a database.Answer
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Related questions
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A dependency of one nonprime attribute on another nonprime attribute is a partial dependency.
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A determinant is any attribute whose value determines other values within a column.
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A table is in 2NF if it is in 1NF, and it includes no partial dependencies.
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Converting a database format from 1NF to 2NF is a complex process.
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In the context of partial dependencies, data redundancies occur because every row entry requires duplication of data.
a. True
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Repeating groups must be eliminated by ensuring that each row defines a single entity.
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Normalization is a process that is used for changing attributes to entities.
a. True
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An entity cluster is formed by combining multiple interrelated entities into_______________ .a. a single abstract entity objectb. multiple abstract entity objectsc. a single entity objectd. multiple entity objects
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Overlapping subtypes are subtypes that contain_______--- subsets of the supertype entity set.a. nullb. exclusivec. solitaryd. nonunique
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c. Subtype discriminators cannot be null.
d. Subtype does not have a supertype.
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The hierarchical model is software-independent.a. Trueb. False