Object/Relational Access Layers A Roadmap, Missing Links and More Patterns

Designing software to connect an object-oriented business system with a relational database is a tedious task. Object-orientation and the relational paradigm differ quite a bit. An application that maps between the two paradigms needs to be designed with respect to performance, maintainability and cost to name just a few requirements. Luckily there are numerous patterns of object/relational access layers, but looking at the body of pattern literature you will find that some patterns are still to be mined, while there's no generative "one stop" pattern language for the problem domain. This paper provides a systematic roadmap of the patterns in the field, and fills some pot holes on the road towards a full pattern language for object/relational access layers by providing some missing patterns and links.