Databases can be distributed among stations on a network to achieve the advantages of performance, reliability, availability, and modularity. Optimal algorithms are designed for simple queries . Optimization principles from these algorithms guide the development of effective heuristic algorithms for general queries on both types of networks.
Several examples illustrate distributed query processing on local area networks.
A query must satisfy a request for retrieving data, which may be located on multiple sites in a network. The method by which this is done is called distributed query processing . The query optimization algorithm specifies the approach by which a query is actually executed on the network. The efficiency of the query optimization algorithm has a major impact on the overall performance of a distributed database system. This paper extends the work to address ring and broadcast LANs.