When setting up a distributed database environment, if the same database management system is used for all the database nodes which take part in this distributed database, then it is termed as a homogeneous distributed database environment.
This environment can be represented as in the diagram here:
The following are some of the characteristics of the homogeneous distributed database environment:
- Information is distributed between all the individual database management system's nodes
- Across all the remote databases, the same database management system is used
- All the information is controlled by the distributed database management system, which will ensure that there is no region-specific information in an individual database
- Every global user must access the information from the same global schema controlled by the distributed database management system
- A combination of all the individual database schemas makes the global schema
The homogeneous distributed database environment is divided into two types, namely, autonomous and non-autonomous.
An autonomous distributed database environment is one that has each of the individual database management systems with the ability to function autonomously and communicate with the other remote database management systems to exchange the information.
A non-autonomous distributed database environment is one that has a master/central database management system, which synchronizes the database access and communicates with the individual nodes to update the information.
Even though organizations want to maintain a homogenous distributed database environment, due to the previously discussed restrictions such as regional licensing constraints, takeovers, application development, or upgrade lifecycles, mergers and splits are difficult to do. Hence, they end up having different database management systems or application software in some of the individual location systems, as discussed in the following section.