Editing Cache replacement policies (section)

==== LFU with dynamic aging (LFUDA) ====
A variant, LFU with dynamic aging (LFUDA), uses dynamic aging to accommodate shifts in a set of popular objects; it adds a cache-age factor to the reference count when a new object is added to the cache or an existing object is re-referenced. LFUDA increments cache age when evicting blocks by setting it to the evicted object's key value, and the cache age is always less than or equal to the minimum key value in the cache.<ref>{{Cite arXiv |eprint = 1001.4135|last1 = Jayarekha|first1 = P.|title = An Adaptive Dynamic Replacement Approach for a Multicast-based Popularity Aware Prefix Cache Memory System|last2 = Nair|first2 = T|class = cs.MM|year = 2010}}</ref> If an object was frequently accessed in the past and becomes unpopular, it will remain in the cache for a long time (preventing newly- or less-popular objects from replacing it). Dynamic aging reduces the number of such objects, making them eligible for replacement,  and LFUDA reduces [[cache pollution]] caused by LFU when a cache is small.