With the advent of the first relational DBMS, it became clear that "that they are inadequate for a broader class of applications" that business data processing applications (Stonebraker et al., 1990). Moreover when we say about necessity to build and use expressive complex business models, the relational DBMSs are not good enough even for the business application (Fowler et al., 2003). This problem was tried to be solved in two ways.