IOPC2

The role of caching is to speed up applications that use persistent objects by delaying database mapping operations. This is generally achieved by taking ownership of these objects when they are not currently in use by the user application. If the user applications needs an already released object again, the caching facility^[10] looks it up in its catalogue and if found, returns it to the user application, saving the time-consuming database operations. The database operations for storing, updating or loading persistent objects are controlled by the cache layer, not by the user application. The layer is therefore responsible for creating and destroying persistent object instances.