Question

Immediate database modification technique uses

(a) Both undo and redo

(b) Undo but no redo

(c) Redo but no undo

(d) Neither undo nor redo

The question was asked at a job interview.

My query is from Lock Release and Undo Operations topic in division Recovery System of Database Management

Answer 1

Correct answer is (a) Both undo and redo

Best explanation: Undo erases all the changes and redo makes the deleted changes.