Practice Library
All MCQs
Browse exam-wise, subject-wise, and country-wise MCQs with explanations.
Choose an option to check your answer.
A.
a statement that only changes font size
B.
a statement that physically changes CPU frequency
C.
a statement that exports images
D.
a statement such as COMMIT or ROLLBACK that manages transaction completion
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Correct Answer: D. a statement such as COMMIT or ROLLBACK that manages transaction completion
Explanation:
transaction control statement is used in Advanced DBMS because a statement such as COMMIT or ROLLBACK that manages transaction completion.
Choose an option to check your answer.
A.
compressing every page before backup
B.
granting users permitted operations on database objects
C.
choosing a join algorithm
D.
reordering projections in a query
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Correct Answer: B. granting users permitted operations on database objects
Explanation:
This statement is correct because authorization means that granting users permitted operations on database objects.
Choose an option to check your answer.
A.
a view through which certain changes can be propagated to base tables when conditions allow
B.
a view used only for recovery logs
C.
a view with no SELECT statement
D.
a view that can never be queried
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Correct Answer: A. a view through which certain changes can be propagated to base tables when conditions allow
Explanation:
The correct answer explains updatable view in the context of Database Administration.
Choose an option to check your answer.
A.
normalization is only a security technique
B.
normalization reduces redundancy but may require joins that affect performance
C.
normalization always eliminates all joins
D.
normalization applies only to MongoDB indexes
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Correct Answer: B. normalization reduces redundancy but may require joins that affect performance
Explanation:
normalization trade-off is used in Advanced DBMS because normalization reduces redundancy but may require joins that affect performance.
Choose an option to check your answer.
A.
a statement that only changes font size
B.
a statement that exports images
C.
a statement that physically changes CPU frequency
D.
a statement such as COMMIT or ROLLBACK that manages transaction completion
Show Answer
Correct Answer: D. a statement such as COMMIT or ROLLBACK that manages transaction completion
Explanation:
This statement is correct because transaction control statement means that a statement such as COMMIT or ROLLBACK that manages transaction completion.
Choose an option to check your answer.
A.
choosing the cheapest query plan
B.
granting SELECT on a table
C.
verifying the identity of a user or application
D.
splitting a table across sites
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Correct Answer: C. verifying the identity of a user or application
Explanation:
The correct answer explains authentication in the context of Integrity and Security.
Choose an option to check your answer.
A.
a view through which certain changes can be propagated to base tables when conditions allow
B.
a view that can never be queried
C.
a view used only for recovery logs
D.
a view with no SELECT statement
Show Answer
Correct Answer: A. a view through which certain changes can be propagated to base tables when conditions allow
Explanation:
updatable view is used in Advanced DBMS because a view through which certain changes can be propagated to base tables when conditions allow.
Choose an option to check your answer.
A.
normalization applies only to MongoDB indexes
B.
normalization is only a security technique
C.
normalization always eliminates all joins
D.
normalization reduces redundancy but may require joins that affect performance
Show Answer
Correct Answer: D. normalization reduces redundancy but may require joins that affect performance
Explanation:
This statement is correct because normalization trade-off means that normalization reduces redundancy but may require joins that affect performance.
Choose an option to check your answer.
A.
a command that opens a file in append mode
B.
a method to bypass authentication
C.
a rule that preserves correctness and validity of database data
D.
a rule that disables every index
Show Answer
Correct Answer: C. a rule that preserves correctness and validity of database data
Explanation:
The correct answer explains integrity constraint in the context of Integrity and Security.
Choose an option to check your answer.
A.
verifying the identity of a user or application
B.
choosing the cheapest query plan
C.
granting SELECT on a table
D.
splitting a table across sites
Show Answer
Correct Answer: A. verifying the identity of a user or application
Explanation:
authentication is used in Advanced DBMS because verifying the identity of a user or application.
Choose an option to check your answer.
A.
a view through which certain changes can be propagated to base tables when conditions allow
B.
a view that can never be queried
C.
a view used only for recovery logs
D.
a view with no SELECT statement
Show Answer
Correct Answer: A. a view through which certain changes can be propagated to base tables when conditions allow
Explanation:
This statement is correct because updatable view means that a view through which certain changes can be propagated to base tables when conditions allow.
Choose an option to check your answer.
A.
converting SQL into machine code
B.
removing all data from tables
C.
enforcing every foreign key twice
D.
intentionally adding redundancy to improve read performance in selected cases
Show Answer
Correct Answer: D. intentionally adding redundancy to improve read performance in selected cases
Explanation:
The correct answer explains denormalization in the context of Physical Design and Tuning.
