Question:
Which of the following statements about the Two Phase Locking (2PL) protocol is/are TRUE?
Which of the following statements about the Two Phase Locking (2PL) protocol is/are TRUE?
Show Hint
2PL ensures serializability but does not prevent deadlocks. Use techniques like timeout or wait-die to handle deadlocks in 2PL.
Updated On: Jan 23, 2025
- 2PL permits only serializable schedules
- With 2PL, a transaction always locks the data item being read or written just before every operation and always releases the lock just after the operation
- With 2PL, once a lock is released on any data item inside a transaction, no more locks on any data item can be obtained inside that transaction
- A deadlock is possible with 2PL
Hide Solution
Verified By Collegedunia
The Correct Option is A
Solution and Explanation
The Two Phase Locking (2PL) protocol ensures two distinct phases: the growing phase (acquiring locks) and the shrinking phase (releasing locks).
Option (A): 2PL permits only serializable schedules by ensuring conflict-serializability. Hence, (A) is correct.
Option (B): This statement is incorrect because locks are not acquired and released immediately for every operation. Locks are held until the shrinking phase.
Option (C): In 2PL, once a lock is released during the shrinking phase, no new locks can be acquired. This is a key property of 2PL. Hence, (C) is correct.
Option (D): Deadlocks can occur in 2PL due to circular wait conditions. Hence, (D) is correct. Final Answer: \[ \boxed{\text{(A), (C), (D)}} \]
Option (A): 2PL permits only serializable schedules by ensuring conflict-serializability. Hence, (A) is correct.
Option (B): This statement is incorrect because locks are not acquired and released immediately for every operation. Locks are held until the shrinking phase.
Option (C): In 2PL, once a lock is released during the shrinking phase, no new locks can be acquired. This is a key property of 2PL. Hence, (C) is correct.
Option (D): Deadlocks can occur in 2PL due to circular wait conditions. Hence, (D) is correct. Final Answer: \[ \boxed{\text{(A), (C), (D)}} \]
Was this answer helpful?
0
0
Top Questions on Miscellaneous
- Let \[ A=\{z\in\mathbb{C}:|z-2|\le 4\} \quad\text{and}\quad B=\{z\in\mathbb{C}:|z-2|+|z+2|=5\}. \] Then the maximum value of \(|z_1-z_2|\), where \(z_1\in A\) and \(z_2\in B\), is:
- JEE Main - 2026
- Mathematics
- Miscellaneous
- Let \[ f(x)=\int \frac{dx}{2\left(\frac{3}{2}\right)^x+2x\left(\frac12\right)^x} \] such that \(f(0)=-26+24\log_e(2)\). If \(f(1)=a+b\log_e(3)\), where \(a,b\in\mathbb{Z}\), then \(a+b\) is equal to:
- JEE Main - 2026
- Mathematics
- Miscellaneous
- Given below are two statements: Statement I: The function \(f:\mathbb{R}\to\mathbb{R}\) defined by \[ f(x)=\frac{x}{1+|x|} \] is one-one. Statement II: The function \(f:\mathbb{R}\to\mathbb{R}\) defined by \[ f(x)=\frac{x^2+4x-30}{x^2-8x+18} \] is many-one. In the light of the above statements, choose the correct answer.
- JEE Main - 2026
- Mathematics
- Miscellaneous
- Let \([\,\cdot\,]\) denote the greatest integer function. Then \[ \int_{-\pi/2}^{\pi/2} \frac{12(3+[x])}{3+[\sin x]+[\cos x]}\,dx \] is equal to:
- JEE Main - 2026
- Mathematics
- Miscellaneous
- The sum of all the elements in the range of
\[ f(x)=\operatorname{sgn}(\sin x)+\operatorname{sgn}(\cos x) +\operatorname{sgn}(\tan x)+\operatorname{sgn}(\cot x), \]
where
\[ x\neq \frac{n\pi}{2},\ n\in\mathbb{Z}, \]
and
\[ \operatorname{sgn}(t)= \begin{cases} 1, & t>0 \\ -1, & t<0 \end{cases} \]
is:
- JEE Main - 2026
- Mathematics
- Miscellaneous
View More Questions
Questions Asked in GATE CS exam
- With respect to a TCP connection between a client and a server, which of the following is true?
- GATE CS - 2026
- Computer Networks
- Let $P, Q, R, S$ be relational schemas. Let ``$\rightarrow$'' indicate a functional dependency (FD) in this context. Which of the following best describes the meaning of a functional dependency?
- GATE CS - 2026
- Database Management Systems
- Let a Non-deterministic Finite Automaton (NFA) have 6 states over a finite alphabet. Which of the following cannot be the number of states in a minimal Deterministic Finite Automaton (DFA) that is equivalent to this NFA?
- GATE CS - 2026
- Theory of Computations
- A certain processor uses a fully associative cache of size 16 kB. The cache block size is 16 bytes. Assume that the main memory is byte addressable and uses a 32-bit address. How many bits are required for the Tag and the Index fields respectively in the addresses generated by the processor?
- GATE CS - 2026
- Computer Organization and Architecture
- Consider $Z = X - Y$, where $X$, $Y$ and $Z$ are all in sign-magnitude form. $X$ and $Y$ are each represented in $n$ bits. To avoid overflow, the representation of $Z$ would require a minimum of:
- GATE CS - 2026
- Computer Organization and Architecture
View More Questions