The optimal working set of a process is the set of pages that will be needed in the immediate future and thus should be resident in the physical memory. The size of the set will be based upon the size of the process and what it needs.
To determine the size of the working window, the OS makes assumptions based upon prior performance of the application that is being run.
Typically when a program runs, there will be several changes and growth of the dynamic window. This should be accounted for, but not so large that it includes all possible memory needs as that could be wasteful.
As the window size grows, the number of page faults decreases. Growth in lower numbers has a large impact, but as it becomes bigger, it has less impact.
The page-fault-frequency replacement algorithm takes a direct approach to controlling the page fault rate by adjusting the current resident set based on how frequently consecutive page faults occur. A “logical guess” at the size d is made. If page faults continue to occur, then it can be increased in size.
Page Replacement with Variable # of Frames was originally found on Access 2 Learn
