problem1. Data replication is an important mechanism commonly employed in a distributed database environment. Replication provides a number of benefits in terms of enhanced system performance.
(i) Discuss the role that data replication plays in distributed database management systems.
(ii) describe the effect that replication has on read-only and update transactions.
(iii) Give details of two strategies for performing updates in a replicated distributed database environment. State one disadvantage of each strategy.
problem2. A database management system is expected to support a sufficient level of database recovery and database concurrency so that the system can function effectively and efficiently.
Discuss and compare the three schemes used for recovery from system failures, namely, deferred update, immediate update, and shadow paging.