8. Elements of choice

Although it is possible to identify the objectives of distributed database management systems and the functionalities required to achieve them, there are currently no standards. This prevents the rational comparison of different systems on the basis of a stable frame of reference, which would be provided by such a standard.

In fact, when we look at a set of systems, they don't usually integrate the same set of functions or services. This precludes a global evaluation: it may be possible to determine a degree of completeness in relation to a list of specific functionalities, or to make a comparison by targeting a particular functionality.

On the other hand, the implementation of distributed applications using database management systems does not require the a priori use of a distributed DBMS. There are many possible strategies for developing...