Question

Which of the following isolation levels allows to read the dirty data?

Select one:
a. SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
b. SET TRANSACTION ISOLATION LEVEL READ COMMITTED;
c. SET TRANSACTION ISOLATION LEVEL REPEATABLE READ;
d. SET TRANSACTION ISOLATION LEVEL READ UNCOMMITED;

Answer 1

The READ UNCOMMITTED isolation level allows the reading of dirty data in a database transaction environment, unlike other more stringent isolation levels.

Step-by-step explanation:

The isolation level that allows the reading of dirty data is READ UNCOMMITTED. Dirty data refers to uncommitted changes made by a transaction; such data can be seen by other transactions only in the READ UNCOMMITTED isolation level. This means that it's possible to read the value of an uncommitted transaction that could potentially be rolled back or altered before being committed, leading to unreliable results. Other isolation levels like READ COMMITTED, REPEATABLE READ, and SERIALIZABLE prevent this level of visibility to maintain data integrity and consistency at different degrees.