DIALOG: a distributed processor organization for database machine

The conventional physical storage mechanism of a computer system is usually comprised of a memory hierarchy that stores program and data. The requirement for high performance and low cost is achieved through a combination of memories of different speeds. By automatically managing the files so that the most frequently used files reside in fast storage, an overall speed comparable to the speed of the fastest memory can be achieved. However, with the applications of large databases, the maintenance of large files on a conventional memory hierarchy becomes increasingly difficult. Most database applications perform a small number of simple operations on a large amount of data. Usually only a small fraction of the data accessed is required by the application. It is more cost effective to perform database operations directly on the data in the secondary storage in order to avoid the transfer of unnecessary data across different levels of the memory hierarchy. The Database Machine (DBM) is the result of an architectural approach which distributes processing power closer to the devices on which data are stored and offloads database processing functions from the main computer [LAN79].