GATE CSE 2024 | Set 2 | Question: 9

Question

​​​​​Once the $\text{DBMS}$ informs the user that a transaction has been successfully completed, its effect should persist even if the system crashes before all its changes are reflected on disk. This property is called

• A. durability
• B. atomicity
• C. consistency
• D. isolation

Comments

References : Korth 

References : Navathe 

 

Answer 1

ACID: Durability

• Changes to database made by committed transaction must persist in spite of any failure.

(Responsibility of the Recovery System.)

Comments

once a transaction is committed its effects must be stored in non-volatile memory which itself must be recoverable from failure.

Answer 2

ACID properties in SQL:

1. Atomicity: Ensures that a transaction is all-or-nothing; it either fully completes or fully fails, leaving the database unchanged if an error occurs.

2. Consistency: Guarantees that a transaction brings the database from one valid state to another, maintaining data integrity according to defined rules.

3. Isolation: Ensures that transactions are executed independently, and the intermediate states are not visible to other transactions.

4. Durability: Ensures that once a transaction is committed, its changes are permanently saved, even in the case of a system failure.

Option (A)

 

Answer 3

A.

Durability

Answer 4

Durability property (informally, also called as property of premanency) in a transaction T ensures that despite encountering any failure after "commit" of a transaction T, all the changes made by transaction T must reflect in database i.e., they must be made permanent in database.

Therefore,  Option A. Durability

Answer 5

a. Durability

Explanation:
Durability ensures that once a transaction is committed, its effects are permanent. Even if the system crashes immediately after the commit, the changes will not be lost. This is typically achieved through logs, backups, and recovery mechanisms.

Hence, the property described is Durability.

Comments

Thanks for Explaination

Answer 6

Durability is responsible for making changes permanent, hence option A