When there are multiple transactions that are taking place at the same time in an uncontrolled or unrestricted manner, sometimes, the order of ‘select’ and ’insert/delete ’ commands may allow the database in different states. This state is called the Phantom Phenomenon.
Consider the following statements.
(a) Select FName
Where salary < 50000 ;
(b) Insert into FACULTY values(‘111’, 22,‘CSE’,’Ramu’,’PhD’, 44000) ;
Here, the order of (a) and (b) will result in different states of the database. This situation is known as ‘Phantom Phenomenon’.