‎"‎A distributed database is a database in which storage devices are not all attached to a common processing unit such as the CPU‎,‎ and which is controlled by a distributed database management system‎.‎ It allows applications to access data from local and remote databases‎.‎ This book discusses the fundamental principles of distributed data management and includes distribution design‎,‎ data integration‎,‎ distributed query processing and optimization‎,‎ distributed transaction management‎,‎ and replication‎.‎‎"‎