Which one of the following is not one of the four ACID properties of a…

Concept

A database transaction is a logical unit of work. The acronym ACID names the four guarantees used to reason about its correctness and persistence.

Those guarantees are Atomicity, Consistency, Isolation, and Durability; each addresses a different failure or concurrency risk.

Application

Compare each offered term with this expansion. Atomicity, Consistency, and Isolation appear in ACID, whereas Deadlock-freedom describes progress in lock management rather than one of the four transaction guarantees.

Contrast and cross-check

• Atomicity: all operations in a transaction take effect together, or none take effect.

• Consistency: integrity constraints remain satisfied before and after the transaction.

• Isolation: concurrent transactions do not expose intermediate states to one another.

• Deadlock-freedom: lock-management logic prevents or breaks circular waiting among transactions.

The missing fourth letter, D, stands for Durability, which means committed changes survive failures. Expanding the acronym therefore distinguishes Durability from Deadlock-freedom.

Result

Therefore, the term that is not part of the ACID properties is Deadlock-freedom.