Question

Another problem that may occur is called unrepeatable read, where a transaction T reads the same item twice and the item is changed by another transaction T between the two reads. Hence, T receives different values for its two reads of the same item. What is this problem called?

1) Unrepeatable Read
2) Dirty Read
3) Phantom Read
4) Lost Update

Answer 1

The issue where a transaction reads the same data item twice and gets different values because it was altered by another transaction in between the reads is called an unrepeatable read.

Step-by-step explanation:

The problem described is known as unrepeatable read. This issue occurs in database systems when a transaction T reads the same data item twice and finds different values each time because another transaction has modified the data item after the first read but before the second read. To answer the question: this problem is called 1) Unrepeatable Read.