The NRDNIX distributed database management system

A distributed database management system must facilitate integrated processing of data which is physically distributed over a network of node computers, while providing locality transparency. \nThe NRDNIX prototype has locality, logical and physical independence as goals, together with adequate availability and efficient throughput. It is architecturally described in terms of an integration of the ANSI/X3/SPARC database management system and the ISO interconnection reference models. Communication takes place via a broadcast network. The data is horizontally distributed over the horizontally controlled nodes, with duplication according to usage. An adaption of the entity-relationship data model is supported, with extensions to the relationships to include update dependencies. \nSome supporting operating systems have been considered. The most promising approach seemed to be the embedding of the distributed database management system kernel in the MINIX operating system. This approach accentuated shortcomings of the MINIX operating system, which deemed it inappropriate for the implementation. A more feasible and popular implementation currently being used is the development of device drivers for the XENIX operating system, for example for the network interface. \nAlthough the NRDNIX prototype is nearing completion, many related research projects must still be undertaken to complete it into a product.