Caching is the process of storing data into temporary memory so that it can be easily retrieved for later use if it is required again. As an example, a database system keeps data cached to avoid rereading the hard drive, and a web browser caches web pages (images and assets) to avoid redownloading the contents. Put simply, in caching, the goal is to maximize hits (an item is in the cache when requested) and minimize misses (an item is not in the cache when requested).
In this chapter, two caching techniques will be discussed: least frequently used (LFU) and least recently used (LRU) caching. ...
