Question
Which of the following page replacement algorithms
results in the lowest page-fault rate for a given reference string but is often impractical to implement in a real-world system?Solution
The Optimal Page Replacement algorithm replaces the page that will not be used for the longest period in the future. It guarantees the lowest page-fault rate for any reference string because it makes perfect decisions based on future knowledge. However, it is impractical to implement in real-world systems because predicting the future sequence of page accesses is impossible. Despite this limitation, the Optimal algorithm serves as a benchmark against which other, more practical algorithms (such as LRU and FIFO) are measured. Why Other Options are Incorrect: A) FIFO: FIFO is easy to implement but often results in more page faults due to its simplistic approach of replacing the oldest page. B) LRU: LRU approximates Optimal in many cases by replacing the least recently used page but is not always perfect. D) Second-Chance Algorithm: This is a variant of FIFO that provides a "second chance" to pages with a reference bit set, but it is less efficient than LRU or Optimal. E) Clock Algorithm: A variation of the Second-Chance Algorithm that is more efficient but still not as good as the Optimal algorithm.
Because of the ___________ interstellar dust and the interior location of the solar system, the spiral structure is very difficult to detect optically.
Select the most appropriate option to fill in the blank.
During the night the express train picked up ______.
Ministers cannot _______ law and orders as an excuse to _______free expression.
In the question given below, one word has been omitted. Choose the most appropriate word from the given options that can fill the blank and make the se...
Located 140 km away from Srinagar, Drass valley in Kargil District is often described as the “Gateway to Ladakh.”
Fill in the blanks in the following sentences with the help of given options.
Either you or Ram ________to help me.
A man from the Japanese City of Osaka has _________ an internet star thanks to his great painting skills. The man has a degree in art but _____ to work ...
While discretion and quiet negotiations are useful, such divergence in public statements also fuels _________ that something deeper and more troubling ...
His new employer gave him some ___________ with which Sam ____________ some food and medicines for his mother. He ___________ all the three friends and ...
The _______ were arrested for illegally hunting the bears.