Distributed data storage systems consist of several physically separated databases that operate independently and appear as a single logical system. The individual logical systems are interconnected via networks. All system components are controlled centrally by a Distributed Database Management System( DDBMS).
The DDBMS system provides data integration and manages the data from the distributed localities centrally as if it were data from a single locality. It periodically synchronizes the data on the distributed database, takes care of updating and deleting new data and deleting data that is no longer needed.
Distributed databases can have a homogeneous or heterogeneous structure. In the homogeneous structures, each DB locality is aware of all others. They work with the same hardware and use the same operating system and DB applications. It is different in the heterogeneous structures, where both the hardware and the operating systems and applications are different.
Distributed data organization requires sophisticated coordination between central and local requirements. One option is to combine different forms of data processing:
Unique data: A data set is stored on only one computer or database server. While this concept means ease of administration, all database access must be sent to that computer. Partitioned data: The entirety of a dataset is distributed across multiple computers, for example, customer data per store. Parallel to this, there is usually a total stock in redundancy. Replicas or redundant data: Replication implies the multiple storage of an entire data stock or a part of it.