13.
14.
15.

16.
अ

18.

19
20.
21.
22.

23.

24.
25.
26.
27.

2 D 41964

Define BCNF.
Explain the Two-Phase Locking protocol to ensure serializability.
When a query language called relationally complete?
(5 x 2 = 10 marks)

Part C
Answer any five questions.
Each question carries 4 marks.

Discuss the main categories of data models.
Define the following :
(a) Entity sets
(b) Relationships
(c) Data independence
(d) Aggregation
Consider the following relations :
Emp (eid, ename, age, salary)
Works (eid, did, time)
Department (did, dname, budget, managerid)
Write SQL DDL statements required to create the above relations with necessary constraints.
Distinguish between relational algebra and relational calculus.
Discuss with example various forms of join operations available in relational algebra.
What are the different data types used in SQL? Explain.

Describe the four important properties of transactions that a DBMS must ensure to maintain
the data in a database.

What is a trigger? Write an example trigger in SQL to illustrate a real life situation.
(5 x 4 = 20 marks)

‘Part D
Answer any five questions.
Each question carries 8 marks.

What are the advantages of using a DBMS? Explain.

What are the responsibilities of the DBA and database designers? 1
With the help of examples, discuss about various set operations defined in relational algebra.
Explain with example, the three different SQL commands used to modify a database.