The spread of the network systems are drastically changing the forms and applications of computer systems. The whole digital media, which would include telephones, televisions, and all the other facilities for communication, are in the processes of global integration.
Database systems, which constitute the integral parts of computer systems, are not excluded from the integration. The simple client-server topology of databases are evolving into the distributed database systems powered by computer networks.
The address space in the persistent storage is so huge for a single computer system that distributed storage manipulation via computer networks should be taken into account.
Some protocols for transmission of persistent objects via network streams must be defined and implemented. Security and robustness will become more and more difficult to achieve in the distributed contexts.