Contents
Does 2PL prevent deadlock?
Conservative 2PL prevents deadlocks.
Why locking is needed explain the 2PL s2pl rigorous 2PL?
Rigorous 2PL means that all locks are released after the transaction ends as opposed to strict where read-only locks may be released earlier. This doesn’t affect deadlocks or starvation as those occur in the expanding phase (a transaction cannot acquire the needed lock).
Is Conservative 2PL deadlock free?
Conservative 2-PL – A.K.A Static 2-PL, this protocol requires the transaction to lock all the items it access before the Transaction begins execution by predeclaring its read-set and write-set. Conservative 2-PL is Deadlock free and but it does not ensure a Strict schedule(More about this here!).
What is lock point?
The “Lock Point” is when all locks are held for the whole transaction. Binds all of the data used in a transaction together. It, therefore, prevents a transaction from being split into parts.
Which is true about rigorous phase locking?
Rigorous two-phase locking is even stricter: here all locks are held till commit/abort. In this protocol transactions can be serialized in the order in which they commit. Same as Strict 2PL but Hold all locks until the transaction has already successfully committed or aborted.
Which is not a state of transaction?
Which of the following is not a transaction state? Explanation: Compensated is not a transaction state. But active, partially committed and failed are different states of a transaction.
Which of the following is a state in transaction?
Explanation: The transaction states are abort, active, committed, partially committed, Failed.
How does the 2PL ( two phase locking algorithm ) work?
For this purpose, the 2PL protocol defines a lock management strategy for ensuring strict serializability. The 2PL protocol splits a transaction into two sections: expanding phase (locks are acquired, and no lock is allowed to be released)
How does two phase locking ensure serializability?
To guarantee serializability, we must follow some additional protocol concerning the positioning of locking and unlocking operations in every transaction. This is where the concept of Two-Phase Locking (2-PL) comes into the picture, 2-PL ensures serializability. Now, let’s dig deep!
Which is the best type of two phase locking protocol?
This is the price we have to pay to ensure serializability and other factors, hence it can be considered as a bargain between concurrency and maintaining the ACID properties. The above-mentioned type of 2-PL is called Basic 2PL. To sum it up it ensures Conflict Serializability but does not prevent Cascading Rollback and Deadlock.
How to test DBMS locking protocol 2PL MCQs based?
DBMS Locking Protocol 2PL MCQ Based Online Test You have already completed the Test before. Hence you can not start it again. Test is loading… You must sign in or sign up to start the Test.