Database design typically includes the physical layout of hardware and software devices that manage a company's data storage. There are multiple techniques that can be applied when designing a database. A distributed database is a database that is split over multiple hardware devices but managed by a central database controller. This distributed approach typically provides better performance and reliability.
Dividing a database into separate physical units has many benefits. This approach provides better control over specific data. It also distributes the load on the computer hardware and network devices.
A distributed database is normally separated by business units, companies, or geographical regions. This approach provides for faster response times for users because the database is local to each business unit within the organization. The business unit is typically smaller then the entire organization, which reduces the overall load on the each server.
Most large companies have separate business units for specific functions. Some examples include accounting, human resources, and sales departments. A distributed database is designed to serve specific business units throughout the organization, while maintaining control from a central server. This technique enables the separation of hardware and data throughout the company, which provides for better control and overall performance.
A distributed database design provides the benefits of central access by corporate headquarters, while enabling local access for specific business units. This is a good design for companies that are disbursed throughout the world. It is also recommend for organizations that support multiple portfolios. Some examples of industries that would benefit from this design include manufacturing, hospitality, and banking.
A distributed database might also be used in an accounting operation. A global organization would typically include a distributed database designed to serve each country. This geographical distribution approach would enable the local country to query data faster. The central database would access each country's data without impacting each local accounting application.
Distributed databases provide better flexibility for a business. With the data divided between multiple servers, it can easily be replicated onto new hardware throughout the organization. This reduces the risk on unavailable data due to hardware failure.
There are some drawbacks to a distributed database design. The most prevalent is database integrity and concurrency. At times the distributed data may become unavailable to the central server. This is typically due to network issues within the computer system. While the database will remain available to the local business units, it may become outdated within the center headquarters of the organization until the network issue is repaired.