Which of the following statements is true about ACID

Solution

Atomicity is a key aspect of database transactions, ensuring that a transaction is treated as a single, indivisible unit. If any part of the transaction fails, the entire transaction is rolled back, leaving the database in its original state. This prevents incomplete transactions from corrupting data. For example, during a fund transfer between two accounts, if the debit operation succeeds but the credit operation fails, the transaction is rolled back, and no changes are made to either account. This guarantees reliability and prevents partial updates, which could lead to data inconsistency. Why Other Options Are Incorrect :

1. ACID ensures that every transaction updates only one table at a time : This is false; ACID applies regardless of the number of tables updated in a transaction.
2. The Isolation property guarantees that no other transaction can execute while one transaction is active : Isolation ensures controlled concurrent execution but does not prohibit simultaneous transactions entirely; it depends on isolation levels like Serializable or Read Committed.
3. Durability ensures data is permanently removed after transaction rollback : Durability guarantees that once a transaction is committed, its changes are permanent, even in case of a system failure. Rollbacks do not affect committed changes.
4. Consistency ensures that multiple transactions can execute simultaneously without any conflicts : Consistency refers to maintaining the correctness of data states before and after a transaction, not concurrency handling.