~pperalta

In his ORM session today, Scott Ambler talked about the impedance mismatch between databases and objects. The technical mismatch is a well known and studied issue. However, he spent quite a bit of time discussing the mismatch between the object and database communities. In particular he addressed the manner in which data people work, which is usually BDUF as opposed to the evolutionary iterative approach that is preferred by object people. As the author of Agile Database Techniques and Refactoring Databases, it is not hard to tell which position Scott takes. However, he does acknowledge that traditional data/DBA types have knowledge and experience that is vital to effective high performance databases. These are skills that OO developers don’t necessarily have. At the same time, data people tend to only view data on its own instead of how it will be used in a real world OO system. He argues that both communities need to work together and to learn a bit about the other’s discipline in order to develop the best applications possible.

He goes on to describe basic ORM techniques, such as how to map inheritance, associations, collections, and so on. The content of the presentation is available on the Agile Data web site.