GATE CSE 2002 | Question: 1.23

Question

The optimal page replacement algorithm will select the page that

• A. Has not been used for the longest time in the past
• B. Will not be used for the longest time in the future
• C. Has been used least number of times
• D. Has been used most number of times

Comments

The optimal page replacement algorithm will select the page that - Will not be used for the longest time in the future.

And that's the reason this optimal Page replacement algorithm is not a practical one and only used for benchmarking because one can never look into future and make decisions in present and that implies in real life too otherwise life would be no fun and boring because then we all take the perfect decisions!

Answer 1

Optimal page replacement algorithm will always select the page that will not be used for the longest time in the future for replacement, and that is why the it is called optimal page replacement algorithm. Hence, (B) choice. 

Comments

option(a) – Least Recently used Page replacement algo

option(b) – Optimal Page replacement algo

option(c) – Least frequently used Page replacement algo

 option(d) –  Most Frequently used Page replacement algo