Databases, especially those used by businesses or accessed by websites, can be opened and used hundreds of times a day. While databases have a variety of functions, there are usually just a few that are popularly used. By using database caching, the function or functions most popularly used are saved into memory so they can be recalled with ease. This makes recalling the function much easier on the computer and drastically reduces the time the computer needs to load the database function. Unlike regular caching, which is done automatically, an administrator must do database caching manually.
Caching is used in computers for a variety of reasons. It can be for databases, memory, central processing unit (CPU) usage, and many other functions. Regardless of what program or function is being used, caching is the same. It means that a chunk of the random access memory (RAM) is used to cache, or store, data. By using this temporary storage technique, the data is easily retrievable, and the computer has to work much less to recall previous information.
Database caching uses a similar principle, but with some differences. Regular computer caching is done automatically by recognizing popular information or just by storing everything temporarily. In database caching, the administrator must choose exactly what information enters the cache.
The information in the cache usually is not part of the database but, rather, a function used on the database. For example, if people accessing the database typically use a function to select data, or to enter information, then these functions will be cached. The actually information being accessed cannot be included in the database cache. After the database caching, these functions require much less work from the computer.
When the administrator chooses to make a database cache, several pieces of hardware that would normally be used are used less. When the cache is made, the CPU no longer has to work on the computation, and the disk access is significantly reduced. At the same time, RAM use is sacrificed, which can be difficult if several computations are needed, but database caching is usually worth having slightly less RAM.
Database caching will not help single users much, because there is little memory used on one user. If the database is accessed by hundreds of website visitors or employees, then the memory savings will become apparent. While this works best for a large base of users, it is always a good practice to cache any functions that are used often to help the computer run smoother.
