Practice Library
All MCQs
Browse exam-wise, subject-wise, and country-wise MCQs with explanations.
Choose an option to check your answer.
A.
indexes are rebuilt after every commit
B.
transaction order is controlled using timestamps assigned to transactions
C.
transactions are ordered alphabetically by user name
D.
queries are sorted by table size only
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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.
Choose an option to check your answer.
A.
transactions are ordered alphabetically by user name
B.
queries are sorted by table size only
C.
transaction order is controlled using timestamps assigned to transactions
D.
indexes are rebuilt after every commit
Show Answer
Correct Answer: C. transaction order is controlled using timestamps assigned to transactions
Explanation:
timestamp ordering is used in Advanced DBMS because transaction order is controlled using timestamps assigned to transactions.
Choose an option to check your answer.
A.
queries are sorted by table size only
B.
indexes are rebuilt after every commit
C.
transactions are ordered alphabetically by user name
D.
transaction order is controlled using timestamps assigned to transactions
Show Answer
Correct Answer: D. transaction order is controlled using timestamps assigned to transactions
Explanation:
The correct answer explains timestamp ordering in the context of Concurrency Control.
Choose an option to check your answer.
A.
the system prevents all reads from happening
B.
the system stores all logs on paper
C.
the system removes all constraints
D.
the system checks for cycles in a wait-for graph and resolves them
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Correct Answer: D. the system checks for cycles in a wait-for graph and resolves them
Explanation:
This statement is correct because deadlock detection means that the system checks for cycles in a wait-for graph and resolves them.
Choose an option to check your answer.
A.
the system prevents all reads from happening
B.
the system checks for cycles in a wait-for graph and resolves them
C.
the system stores all logs on paper
D.
the system removes all constraints
Show Answer
Correct Answer: B. the system checks for cycles in a wait-for graph and resolves them
Explanation:
deadlock detection is used in Advanced DBMS because the system checks for cycles in a wait-for graph and resolves them.
Choose an option to check your answer.
A.
the system checks for cycles in a wait-for graph and resolves them
B.
the system removes all constraints
C.
the system stores all logs on paper
D.
the system prevents all reads from happening
Show Answer
Correct Answer: A. the system checks for cycles in a wait-for graph and resolves them
Explanation:
The correct answer explains deadlock detection in the context of Concurrency Control.
Choose an option to check your answer.
A.
a method used only for file compression
B.
a strategy that never uses timestamps
C.
a strategy that avoids deadlocks before they occur using rules such as wait-die or wound-wait
D.
a method that deletes all waiting transactions randomly
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Correct Answer: C. a strategy that avoids deadlocks before they occur using rules such as wait-die or wound-wait
Explanation:
This statement is correct because deadlock prevention means that a strategy that avoids deadlocks before they occur using rules such as wait-die or wound-wait.
Choose an option to check your answer.
A.
a strategy that never uses timestamps
B.
a method used only for file compression
C.
a strategy that avoids deadlocks before they occur using rules such as wait-die or wound-wait
D.
a method that deletes all waiting transactions randomly
Show Answer
Correct Answer: C. a strategy that avoids deadlocks before they occur using rules such as wait-die or wound-wait
Explanation:
deadlock prevention is used in Advanced DBMS because a strategy that avoids deadlocks before they occur using rules such as wait-die or wound-wait.
Choose an option to check your answer.
A.
a method used only for file compression
B.
a strategy that never uses timestamps
C.
a method that deletes all waiting transactions randomly
D.
a strategy that avoids deadlocks before they occur using rules such as wait-die or wound-wait
Show Answer
Correct Answer: D. a strategy that avoids deadlocks before they occur using rules such as wait-die or wound-wait
Explanation:
The correct answer explains deadlock prevention in the context of Concurrency Control.
Choose an option to check your answer.
A.
a query chooses a full table scan
B.
two or more transactions wait for each other so none can proceed
C.
a transaction commits successfully after reading
D.
a database creates an index automatically
Show Answer
Correct Answer: B. two or more transactions wait for each other so none can proceed
Explanation:
This statement is correct because deadlock means that two or more transactions wait for each other so none can proceed.
Choose an option to check your answer.
A.
a database creates an index automatically
B.
a transaction commits successfully after reading
C.
two or more transactions wait for each other so none can proceed
D.
a query chooses a full table scan
Show Answer
Correct Answer: C. two or more transactions wait for each other so none can proceed
Explanation:
deadlock is used in Advanced DBMS because two or more transactions wait for each other so none can proceed.
Choose an option to check your answer.
A.
a database creates an index automatically
B.
two or more transactions wait for each other so none can proceed
C.
a transaction commits successfully after reading
D.
a query chooses a full table scan
Show Answer
Correct Answer: B. two or more transactions wait for each other so none can proceed
Explanation:
The correct answer explains deadlock in the context of Concurrency Control.
