For many types of organization, the ultimate information handling aspiration is to have an integrated database system so that common files can be consulted by various sections of the organization, in an efficient and effective manner. However, database systems are not just pertinent to organizations or even large sections of enterprises. Many users of personal computers now accept a database management system (DBMS) as an integral part of their computing software almost as important as an operating system. Databases are no longer confined to the province of large-scale users.

The addition of communications facilities to a database system can take it from a centralized concept to a decentralized concept. The reservoir of data need not all be situated at a single site on a single computing facility. Neither does the database have to be confined within the boundaries of a single organization or corporation.

Now this has caused some debate among commentators on technology. For a long time, even predating the advent of electronic computers, the notion has been around that computers will start to 'take over' and control the destiny of homo sapiens. This has recently been countered by pointing to the wide availability of personal computers and the possibility of linking them through increasingly sophisticated communications facilities. A message of great freedom and decentralization is now being preached in some quarters. The other side can of course argue back.

We do not wish to contribute directly to this debate. On the other hand, we do wish to present the core knowledge of one particular aspect - the data-handling aspect - of distributed computing which impacts on both of the views stated above.