The Cache-aside pattern can be used to improve performance by loading frequently referenced data in a local or faster form of storage. With this pattern, it is the responsibility of the application to maintain the state of the cache. This is illustrated in the following diagram:

First, the application requests information from the cache. If the information is missing, then it is requested from the data store. The application then updates the cache with the information. Once the information is stored, it will then be retrieved from the cache and used without referencing the slower data store. With this pattern, it is the application's responsibility to maintain the cache, both when there is a cache miss, and when the data is updated.