Question

    Which of the following statements correctly describes the ACID property "Durability" in database transactions? 

    A Ensures that a transaction remains valid only if no other concurrent transactions modify the data Correct Answer Incorrect Answer
    B Guarantees that a transaction is reversible if an error occurs during execution Correct Answer Incorrect Answer
    C Verifies that all operations within a transaction are completed in a single atomic unit Correct Answer Incorrect Answer
    D Confirms that once a transaction is committed, the changes persist even in the event of a system failure Correct Answer Incorrect Answer
    E Prevents unauthorized access to data by ensuring secure transactions Correct Answer Incorrect Answer

    Solution

    Durability is an essential property of the ACID model in database transactions, which stands for Atomicity, Consistency, Isolation, and Durability. Durability guarantees that once a transaction has been committed, its changes are permanent, even in cases of system crashes or power failures. This property is typically ensured through logging and backup mechanisms that maintain committed data on stable storage, such as hard drives or SSDs, rather than volatile memory. Durability is crucial in systems where data integrity and reliability are vital, as it ensures that the database remains consistent and reliable after unexpected failures, reinforcing the resilience of the database system. Option A - This describes the Isolation property, which ensures that concurrent transactions do not interfere with each other. Option B - Reversibility is not a part of the Durability property; rather, it aligns more with error handling and rollback mechanisms related to Atomicity. Option C - Atomicity ensures that all operations within a transaction are treated as a single unit, completing fully or not at all, unrelated to Durability. Option E - While securing transactions is essential, it is more related to database security rather than the concept of Durability within ACID properties.

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