Distributed database management system (DDBMS) is different from a centralized database management system (DBMS) in many aspects.
In the case of DDBMS data is distributed across the network nodes. Unlike the DBMS data is not stored and controlled at a central location, rather it is stored at different sites and DDBMS is responsible of managing all the data. Thus there is an overhead of network that is not faced by DBMS unlike the DDBMS.
DDBMS provides the access to distributed databases through the same interface as in DBMS, but for this purpose DDBMS faces more complications than DBMS.
Data is distributed over the network either by fragmentation or by replication.
In either case it is objective of DDBMS to transparent this distribution to the user. Transparency means separation of high level semantics of system from low level implementation issues. In other words transparent system hides the implementation details from users.
And DDBMS must provide the transparency at four levels like network transparency, fragmentation transparency, replication transparency etc.
All these transparencies are not needed in DBMS.
Thus, DDBMS is more sophisticated than DBMS because it support the organizational structure of today's widely distributed enterprises, and more responsive and reliable.
In the case of DDBMS data is distributed across the network nodes. Unlike the DBMS data is not stored and controlled at a central location, rather it is stored at different sites and DDBMS is responsible of managing all the data. Thus there is an overhead of network that is not faced by DBMS unlike the DDBMS.
DDBMS provides the access to distributed databases through the same interface as in DBMS, but for this purpose DDBMS faces more complications than DBMS.
Data is distributed over the network either by fragmentation or by replication.
In either case it is objective of DDBMS to transparent this distribution to the user. Transparency means separation of high level semantics of system from low level implementation issues. In other words transparent system hides the implementation details from users.
And DDBMS must provide the transparency at four levels like network transparency, fragmentation transparency, replication transparency etc.
All these transparencies are not needed in DBMS.
Thus, DDBMS is more sophisticated than DBMS because it support the organizational structure of today's widely distributed enterprises, and more responsive and reliable.