Discuss the extended capabilities or services that a DDBMS must provide over a centralized DBMS.

What will be an ideal response?

? extended communication services to provide access to remote sites and allow the transfer of
queries and data among the sites, using a network;
? extended Data Dictionary to store data distribution details;
? distributed query processing including query optimization and remote data access;
? extended concurrency control to maintain consistency of replicated data;
? extended recovery services to take account of failures of individual sites and the failures of
communication links.