Test Papers / Previous Question Papers of IGNOU CS06 Database Management System June 2005

PGDCA / MCA (I Yr)
Term-End Examination

June, 2005

CS06 : Database Management System

Time: 3 hours
Maximum Marks: 75

1. (a) (a) Suppose you have been designated as a database administrator of an organization. Describe the responsibilities that may be generally assigned to you in order to maintain the centralised database efficiently. Also, include at least 2 responsibilities with respect to the Database security. (7)

(b) Create an ER diagram for the loan management system of a finance company. Loans are given on the purchase of various items with different interest rates. The company keeps track of defaulters and takes appropriate steps against them. Make, and state, suitable assumptions (if any). (8)

(c) Explain the three level architecture of DBMS, including the diagram. How is the mapping between these levels achieved ? (7)

Explain the evolution of Client/Server Architecture. List the components and the usage in Client/Server computing. Mention any two applications of this model. (8)

2. (a) What is a knowledge based system ? Mention any two advantages and disadvantages of it. Give any two examples where a knowledge based system is used. Discuss the rule based knowledge representation scheme with the help of an example. (10)

(b) What are the problems caused by data redundancies ? Can data redundancies be completely eliminated when a database approach is used ? Explain this with the help of an example. (5)

3. (a) Write the significance of the evaluation ol a database management system. List the technical and administrative issues respectively, required to be taken care of by the evaluation team. (7)

(b) Draw a diagram to illustrate the relationship of different file organizations based on an access key. What is direct file organization ? Explain the role of hashing in direct file organization with the help of an example. (8)

4. (a) Consider the following schema :
employee (e_no, e_name, address, city, basic_sal, job_status)
projects (p_no, p_name, p_category)
work_in (p_no. e_no, p_duration)
Write appropriate SQL queries for the following : (6)
(i) Display the names of employees who are working in a project on "DBMS".
(ii) Find the employer number of all employees who are working on at least one project.
(iii) Find the average salary of all employees working in a project "based in Delhi".

(b) Describe any three differences between the object oriented data model and the relational data model. ln what ways is the object oriented data model similar to the hierarchical and network data models ? Mention any two examples in which we can use the object oriented databases and relational databases, with the proper justification. (9)

5. (a) Explain the trade-offs in distributing the database. List the issues involved in storing the relations in the distributed databases. (9)

(b) What are the different relational operators used in relational algebra ? Consider the following relations A and B, and perform A U B, A ∩ B and A - B. (6)