As Java developers, we are used to handling relational database persistence through the use of mature and well-established JPA frameworks such as Hibernate or EclipseLink. Despite the fact that these frameworks are convenient to use and hide a lot of the complexity for retrieving or updating data that is spread over several tables, Object-Relational Mapping suffers from the Object-Relational Impedance Mismatch problem; in an object-oriented model, you traverse objects via their relationships, whereas in a relational database, you join the data rows of tables, resulting sometimes in an inefficient and cumbersome retrieval of data. (This is further explained on the Wikipedia page, http://en.wikipedia.org/wiki/Object-relational_impedance_mismatch.)

In contrast, the Slick framework that is part of the Typesafe stack proposes to solve the persistence of data to relational databases through a Functional Relational Mapping, which strives for a more natural fit. Some of the additional...