Practice Library
All MCQs
Browse exam-wise, subject-wise, and country-wise MCQs with explanations.
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Correct Answer: C. a transaction reads data written by another transaction that has not yet committed
Explanation:
The correct answer explains dirty read in the context of Concurrency Control.
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Correct Answer: C. a lock that allows concurrent reading but prevents conflicting writes
Explanation:
shared lock is used in Advanced DBMS because a lock that allows concurrent reading but prevents conflicting writes.
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Correct Answer: B. transaction order is controlled using timestamps assigned to transactions
Explanation:
This statement is correct because timestamp ordering means that transaction order is controlled using timestamps assigned to transactions.
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Correct Answer: A. a recovery algorithm based on analysis, redo, and undo phases
Explanation:
The correct answer explains ARIES recovery in the context of Recovery.
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Correct Answer: C. a transaction reads data written by another transaction that has not yet committed
Explanation:
dirty read is used in Advanced DBMS because a transaction reads data written by another transaction that has not yet committed.
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Correct Answer: B. a lock that allows concurrent reading but prevents conflicting writes
Explanation:
This statement is correct because shared lock means that a lock that allows concurrent reading but prevents conflicting writes.
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Correct Answer: C. transactions execute first and are validated before commit
Explanation:
The correct answer explains optimistic concurrency control in the context of Concurrency Control.
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Correct Answer: D. a recovery algorithm based on analysis, redo, and undo phases
Explanation:
ARIES recovery is used in Advanced DBMS because a recovery algorithm based on analysis, redo, and undo phases.
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Correct Answer: B. a transaction reads data written by another transaction that has not yet committed
Explanation:
This statement is correct because dirty read means that a transaction reads data written by another transaction that has not yet committed.
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Correct Answer: B. a lock required for writing that prevents other conflicting reads or writes
Explanation:
The correct answer explains exclusive lock in the context of Concurrency Control.
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Correct Answer: D. transactions execute first and are validated before commit
Explanation:
optimistic concurrency control is used in Advanced DBMS because transactions execute first and are validated before commit.
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Correct Answer: A. a recovery algorithm based on analysis, redo, and undo phases
Explanation:
This statement is correct because ARIES recovery means that a recovery algorithm based on analysis, redo, and undo phases.
