Question

Problems occurs if we don’t implement a proper locking strategy

(a) Dirty reads

(b) Phantom reads

(c) Lost updates

(d) Unrepeatable reads

The question was asked during an interview.

My enquiry is from Transformation of Relational Expressions topic in portion Query Processing Techniques of Database Management

Answer 1

Right choice is (b) Phantom reads

To explain: Phantom reads occur when an insert or delete action is performed against a row that belongs to a range of rows being read by a transaction.