MCA - 2205
2393-1/02

M.C.A. DEGREE EXAMINATION - 2002
Second Year - Second Semester
DISTRIBUTED DATA BASES SYSTEMS
(Effective from the Admitted Batch of 2000-2001)

Time: Three hours
Maximum: 75 marks

First question is compulsory.
Answer any FOUR from the remaining questions.
All questions carry equal marks.
Write all bits of the first question at one place.

1. (5 x 3 = 15)

(a) Define a distributed database with respect to logical correlation.

(b) What are required for the bottom-up design of a distributed database?

(c) What is the property of the "Group - by operation"?

(d) Write three properties of a transaction.

(e) What is meant by false deadlock?

2. What are the various possible forms of transparencies in distributed DBMS? Explain briefly each of them. (15)

3. (a) Write various types of accesses methods to a DDBMS. (8+7)

(b) Draw the suitable diagram for the reference architecture for distributed databases and explain.

4. (a) Explain about Horizontal Fragmentation and derived Horizontal Fragmentation with suitable example. (8+7)

(b) What do you know about Transparency for "Read-only Applications"? Explain.

5. (a) Write about various objectives of the design of data distribution. (8+7)

(b) What are the objectives of query processing?

6. Explain about the design principles of database fragmentation. (15)

7. Give an example of global schema, fragmentation schema and additional semantic knowledge, such that all this information can be used for deducing the simplification of a query. (15)

8. Write short notes on the following: (3 x 5)

(a) Recovery in centralized system

(b) 2-phase - commitment protocol

(c) Distributed concurrency control method.