The problem of building DBMSs on top of the existing operating systems are well-documented. The common result is that DBMSs either bypass the operating systems, treat the disk as raw disk, and implement their own functions thereby duplicating some of the functions of the operating system, or they modify the operating system itself. Part of this problem is architectural and independent of the approach used to model system entities. However, as will be indicated below, object-orientation is expected to be of help. This problem arises because of the differences in the level of abstraction between the relational languages and the programming languages with which they interact.
Relational systems provide a declarative and set-oriented language for accessing flat tables.
The applications mentioned above require richer database languages which overcome this impedance mismatch. Even though the potential exists for such a uniform treatment, this is easier said than done. The approach to object-orientation of these three systems are quite different. The final reason for the interest in object-orientation is its potential for facilitating interoperability. In fact, many practitioners have pointed out that, in the long run, this may be the most important and most influential use of object-oriented technology.