LRU

LRU

Least Recently Used. An algorithm that removes the least recently used item from a store when space is required.

Many caching algorithms use an LRU algorithm, removing from the cache the least recently used item. For example, many database systems use an LRU algorithm when determining which data items to remove from memory so to do many paging algorithms.

The least recently used item is the item in the store which has not been used for the longest. It should not be confused with the oldest (or earliest loaded) item in the store - the oldest item may be the least recently used, but if it was last accessed more recently than another then it would not be the least recently used.