Databases can record transactions in real time, which usually updates more thanone database in a distributed environment. This type of complexity can introduce many integrity threats, so the database software should implement the characteristics of what’s known as the ACID test. Which of the following are incorrect characteristics of the ACID test?

i. Atomicity – Divides transactions into units of work and ensures that all modifications take effect or none takes effect.
ii. Consistency – A transaction must follow the integrity policy developed for that particular database and ensure all data are consistent in the different databases.
iii. Isolation – Transactions execute in isolation until completed, without interacting with other transactions.
iv. Durability – Once the transaction is verified as inaccurate on all systems, it is committed, and the databases cannot be rolled back.

A.
i

B.
ii, iii

C.
i, ii, iii

D.
iv

Explanation:
The following are correct characteristics of the ACID test:

– Atomicity Divides transactions into units of work and ensures that all modifications take effect or none takes effect. Either the changes are committed orthe database is rolled back.
– Consistency A transaction must follow the integrity policy developed for that particular database and ensure all data are consistent in the different databases.
– Isolation Transactions execute in isolation until completed, without interacting with other transactions. The results of the modification are not available until the transaction is completed.
– Durability Once the transaction is verified as accurate on all systems, it is committed, and the databases cannot be rolled back.