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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.
- First
- Second
- Third
- 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.
- One
- Two
- Three
- 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?
- An extension of Multivalued Dependencies is Join Decomposition.
- It is possible to call the join of R1 and R2 over C a join dependency (JD) if they are equal to relation R.
- Alternatively, R1 and R2 can be written as lossless decompositions of R.
- All of the above
Answer: D) All of the above
Explanation:
In case of Join Dependency -
- An extension of Multivalued Dependencies is Join Decomposition.
- It is possible to call the join of R1 and R2 over C a join dependency (JD) if they are equal to relation R.
- 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.
- Multivalued Dependencies
- Join Dependencies
- Both A and B
- 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.
- Join
- Multivalued
- Inclusion
- 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?
- Primary key
- Foreign key
- Alternate key
- 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.
- Primary
- Foreign
- Composite
- 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.
- Join
- Multivalued
- Inclusion
- 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.
- Be
- Not be
- Always
- 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 ____.
- Formula
- Table
- Database
- 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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