Techniques are disclosed relating to retrieving data from an in-memory cache, such as that for a database system. In various embodiments, an in-memory cache receives a request from an application for data, where the request specifies a class having a function executable to access the data from a location external to the cache in response to a cache miss. The cache handles the request such that the cache miss is not returned to the application. Specifically, the cache, in some embodiments, determines whether it stores the requested data, and in response to determining that it does not store the data, calls the function of the class to access the data from the location external to the cache and receives the data returned by the execution of the function. The cache then stores the received data in the cache and returns the received data in response to the request.