This monograph explores efficient query processing techniques for nearest neighbor queries from a spatial database perspective. It provides basic concepts and an introduction to spatial databases and parallel processing research, then goes on to discuss numerous applications of nearest neighbor queries, such as query processing in a single-processor multi-disk system environment, and in systems composed of many disks and processors. Enriched by numerous illustrations and pointers for additional research, this book is an excellent reference for students, researchers and professionals interested in nearest neighbor search and related issues.