Solution
The correct answer is Deadlock-freedom
Key PointsACID properties of a database transaction
- Atomicity: It means that a transaction is treated as a single, indivisible logical unit of work, in which either all steps are performed or none are. If any step in a transaction fails, the entire transaction is rolled back, and the database is left unchanged.
- Consistency: This refers to ensuring that a transaction brings the database from one valid state to another. The database has integrity constraints, and it's the responsibility of the transaction to maintain these constraints. Hence, any transaction will take a database from one consistent state to another.
- Isolation: This property ensures that concurrent execution of transactions leaves the database in the same state as if the transactions were executed sequentially. It enables transactions to execute independently without interference.
- Durability: This property ensures that once a transaction has been committed, it will remain committed even in the presence of failures (system crash, power loss, etc.). The effects of an executed transaction are persistent and can survive any subsequent malfunction.
On the other hand, "deadlock-freedom" is not a part of ACID. Deadlocks are a condition where two or more transactions are unable to proceed because each holds a lock that the other needs. Deadlock prevention and detection are indeed crucial aspects of database management systems but are not included in the ACID properties.
