Match the following : \(\begin{array}{clcl} & \textbf{List – I} &&…
2014
Match the following :
\(\begin{array}{clcl} & \textbf{List – I} && \textbf{List – II} \\ \text{a.} & \text{Timeout ordering protocol} & \text{i.} & \text{Wait for graph} \\ \text{b.} & \text{Deadlock prevention} & \text{ii.} & \text{Roll back} \\ \text{c.} & \text{Deadlock detection} & \text{iii.} & \text{Wait-die scheme} \\ \text{d.} & \text{Deadlock recovery} & \text{iv.} & \text{Thomas Write Rule} \\ \end{array}\)
Codes :
- A.
a-iv; b-iii; c-i; d-ii
- B.
a-iii; b-ii; c-iv; d-i
- C.
a-ii; b-i; c-iv; d-iii
- D.
a-iii; b-i; c-iv; d-iii
Attempted by 77 students.
Show answer & explanation
Correct answer: A
To solve this matching question, analyze each item in List I and match it with the correct corresponding item in List II based on database concurrency control concepts.
Timeout ordering protocol (a) → Thomas Write Rule (iv):This protocol uses timestamp-based methods to resolve conflicts. The Thomas Write Rule is a specific rule that allows a transaction to skip writing if its timestamp is older than the read timestamp of the data item, thus avoiding unnecessary rollbacks.
Deadlock prevention (b) → Wait-die scheme (iii):This is a timestamp-based deadlock prevention strategy. Older transactions are allowed to wait for younger ones, but younger transactions requesting resources held by older ones are aborted ("died").
Deadlock detection (c) → Wait-for graph (i):The system maintains a wait-for graph where transactions are nodes and edges represent resource waits. A cycle in this graph indicates a deadlock.
Deadlock recovery (d) → Roll back (ii):After detecting a deadlock, the system selects a victim transaction and rolls it back to a previous consistent state to break the deadlock cycle.
Thus, the correct matching is a-iv, b-iii, c-i, d-ii.