Multiple choice

Which of the following scenarios may leaves the transaction vulnerable to dirty reads, phantom reads etc.. in a database system?

  1. A transaction writes a data item after it is read by an uncommitted transaction.

  2. A transaction reads a data item after it is read by an uncommitted transaction.

  3. A transaction reads a data item after it is written by a committed transaction.

  4. A transaction reads a data item after it is written by an uncommitted transaction.

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

 This may leave the transactions vulnerable to dirty reads, phantom reads, etc. in the database system.