A database administrator is concerned about transactions in case the system fails. Which of the following properties addresses this concern?

The Durability property of ACID (Atomicity, Consistency, Isolation, Durability) ensures that once a transaction has been successfully committed, its changes are permanently recorded and will survive any subsequent system failure, such as a power outage or crash. The database management system guarantees that the results of committed transactions are written to non-volatile storage (e.g., a hard disk). This directly addresses the administrator's concern about the persistence of transactions in the event of a system failure.

B. Isolation: This property ensures that concurrent transactions do not interfere with each other, making them appear to execute serially. It addresses concurrency, not system failure recovery.

C. Atomicity: This property ensures that a transaction is an "all-or-nothing" operation. Either all of its operations are completed successfully, or none of them are. It prevents partial updates.

D. Consistency: This property ensures that a transaction brings the database from one valid state to another, preserving all predefined integrity constraints. It is about data correctness, not persistence after a crash.

1. Haerder

T.

& Reuter

A. (1983). Principles of Transaction-Oriented Database Recovery. ACM Computing Surveys

15(4)

287–317.

Page 290

Section 2.4: "Once a transaction is committed

its effects are permanent in the database... This property is called durability. The effects of a committed transaction must not be abrogated by any type of failure."

DOI: https://doi.org/10.1145/289.291

2. Halevy

A.

& Franklin

M. (2005). Transaction Processing. In P. A. Bernstein

U. Dayal

& D. B. Lomet (Eds.)

Principles of Transaction Processing for the Systems Professional (2nd ed.). Morgan Kaufmann.

Chapter 1

Section 1.2

"The ACID Properties": "Durability means that once a transaction commits

its effects are permanent. The changes must not be lost in a failure."

3. MIT OpenCourseWare. (2010). 6.830 Database Systems

Lecture 17: Crash Recovery. Massachusetts Institute of Technology.

Slide 4

"ACID Properties": Defines Durability as: "Effects of a committed transaction are permanent

must not be lost by a crash."

Available at: https://ocw.mit.edu/courses/6-830-database-systems-fall-2010/resources/mit6830f10lec17/