ADBMS-UNIT4-QUESTIONS

Unit4

1.       Describe the three main architectures of parallel DBMSs with neat diagram. Explain why shared nothing architecture is more attractive than shared-memory and shared-disk approaches?

2.       Define the term scale–up and speed–up in parallel database systems. What can you say about the speed-up and scale-up of the shared-nothing architecture?

3.       Briefly explain two kinds of interoperation parallelism that can be exploited within a query.  Explain the data partitioning and parallelization of sequential operation evaluation in detail.

4.       Discuss joins in parallelizing individual operations.  Also explain improved parallel hash join.

5.       What are the functions that need to be provided by distributed databases in addition to those of centralized DBMS ?  What are the different types of distributed database system?

6.       Discuss different types of data fragmentation in distributed database design. Distinguish between horizontal and vertical fragmentations.

7.       What is the difference between synchronous and asynchronous replication with regard to updating distributed data? Why has asynchronous replication gained in popularity? Describe the voting and read- any write-all approaches to synchronous replication. Also summarize the peer-to-peer and primary site approaches to asynchronous replication.

8.       Discuss the query processing in distributed databases. Describe semijoins and bloomjoins with respect to join of relations at different sites.

9.       Explain the distributed concurrency control. Why distributed recovery is needed?

10.    Explain the need for a commit protocol in a distributed DBMS. Explain 2 Phase commit Protocol in detail specifying the list of messages initiated by 2PC.