The impact of parallel computing on database processing is likely to be highly significant creating new opportunities for applications which cannot be accommodated with single processor architectures. With the emergence of mobile computing the corporate information system also includes notebook computers and other portable devices. Similar to desktop computing users, mobile users need access to information stored on corporate database servers. In some cases, mobile users carry fragments of the corporate database with them in notebook databases and from time to time need to synchronize their information with the information held on the remote server. Mobile computing can be regarded as a special type of distributed environment and presents a number of technical problems for database implementation.
Mobile communications are non-continuous and generally unreliable causing poor system availability.
Asynchronous processing using store and forward techniques are best suited to this type of environment. During periods when the mobile station is disconnected, messages are stored in a queue and transmission is resumed when communications are re-established. In situations where the mobile station also carries data, the resulting environment can be characterized as a distributed database. Summary New types of applications have created a situation where the existing database server technology is no longer sufficient. Both the size and the complexity of databases have dramatically increased forcing database researchers to develop new data and transaction models.