DBMS Types of Dependency MCQs

DBMS Types of Dependency MCQs: This section contains multiple-choice questions and answers on types of dependency in DBMS.
Submitted by Anushree Goswami, on April 04, 2022

1. When there is a multivalued dependency in a table, two attributes are independently determined by each other, but both are dependent upon ___ attribute.

  1. First
  2. Second
  3. Third
  4. Fourth

Answer: C) Third

Explanation:

When there is a multivalued dependency in a table, two attributes are independently determined by each other, but both are dependent upon a third attribute.

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2. At least two attributes of a multivalued dependency must be dependent upon a third attribute, hence it always requires _____ attributes.

  1. One
  2. Two
  3. Three
  4. Four

Answer: C) Three

Explanation:

At least two attributes of a multivalued dependency must be dependent upon a third attribute, hence it always requires three attributes.

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3. What is true about Join Dependency?

  1. An extension of Multivalued Dependencies is Join Decomposition.
  2. It is possible to call the join of R1 and R2 over C a join dependency (JD) if they are equal to relation R.
  3. Alternatively, R1 and R2 can be written as lossless decompositions of R.
  4. All of the above

Answer: D) All of the above

Explanation:

In case of Join Dependency -

  1. An extension of Multivalued Dependencies is Join Decomposition.
  2. It is possible to call the join of R1 and R2 over C a join dependency (JD) if they are equal to relation R.
  3. Alternatively, R1 and R2 can be written as lossless decompositions of R.

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4. Although more rarely used than functional dependencies, ___ can guide database design.

  1. Multivalued Dependencies
  2. Join Dependencies
  3. Both A and B
  4. None of the above

Answer: C) Both A and B

Explanation:

Although more rarely used than functional dependencies, multivalued dependencies and join dependencies can guide database design.

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5. Basically, ___ dependencies are statements where some columns of a relation are contained within other columns.

  1. Join
  2. Multivalued
  3. Inclusion
  4. All of the above

Answer: C) Inclusion

Explanation:

Basically, inclusion dependencies are statements where some columns of a relation are contained within other columns.

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6. What is an example of Inclusion Dependency?

  1. Primary key
  2. Foreign key
  3. Alternate key
  4. Composite key

Answer: B) Foreign key

Explanation:

An example of Inclusion Dependency is Foreign Key.

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7. The ___ key columns(s) of the referenced relation contain the referring relation.

  1. Primary
  2. Foreign
  3. Composite
  4. Alternate

Answer: A) Primary

Explanation:

The primary key columns(s) of the referenced relation contain the referring relation.

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8. It would be considered ___ dependency if projecting R on its key attributes led to a relation which is contained in the relation obtained by projecting S on its key attributes.

  1. Join
  2. Multivalued
  3. Inclusion
  4. None

Answer: C) Multivalued

Explanation:

It would be considered inclusion dependency if projecting R on its key attributes led to a relation which is contained in the relation obtained by projecting S on its key attributes.

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9. The inclusion dependency should ___ broken up into different sets of attributes.

  1. Be
  2. Not be
  3. Always
  4. None of the above

Answer: B) Not be

Explanation:

The inclusion dependency should not be broken up into different sets of attributes.

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10. It is common for inclusion dependencies to be ____-based, that is, they deal with only ____.

  1. Formula
  2. Table
  3. Database
  4. Key

Answer: D) Key

Explanation:

It is common for inclusion dependencies to be key-based, that is, they deal with only keys.

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