(AUTONOMOUS)
B. Tech VII Semester Supplementary Examinations, May 2018
(Regulations: VCE-R14)
DATABASE MANAGEMENT SYSTEMS
(Electronics and Communication Engineering)
Date: 24 May, 2018 AN Time: 3 hours Max Marks: 75
Answer ONE question from each Unit
All Questions Carry Equal Marks
Unit I
1. Discuss the four significant differences between file-processing system and DBMS. 8M
A company database needs to store information about employees (identified by ssn,
with salary and phone as attributes), departments (identified by dno, with dname and
budget as attributes), and children of employees (with name and age as attributes).
Employees work in departments; each department is managed by an employee; a child
must be identified uniquely by name when the parent (who is an employee; assume that
only one parent works for the company) is known. Draw an ER diagram that captures this
information.
7M
2. What are the responsibilities of a DBA? If we assume that the DBA is never interested in
running his or her own queries, does the DBA still need to understand query
optimization? Why?
7M
With suitable examples discuss the two kinds of constraints with respect to IS-A
hierarchies in ER diagrams.
8M
Unit II
3. What do you mean by aggregate functions in SQL? Explain with the help of example. 7M
How will you eliminate duplicates from the result of a SELECT statement? And also find
the difference between IN and BETWEEN classes? Explain with examples.
8M
4. Explain with examples how Attribute constraints, Key constraints and Referential
integrity constraints be specified in SQL.
7M
With examples explain the concept of views and also give example on the DROP and
ALTER commands in SQL with examples.
8M
Unit III
5. Explain normalization in relational database design. Define 1NF, 2NF, 3NF and BCNF. 7M
Define functional dependency. List well known inference rules for functional
dependencies.
8M
6. Explain Schema refinement in database design. 7M
What is decomposition? Discuss the properties of Decomposition.
8M
Unit IV
7. What are the various states of a transaction? Explain with a neat diagram. 7M
What are ACID properties? Why are they desirable?
8M
8. Discuss the timestamp ordering protocol for concurrency control. 7M
Explain log-based recovery in database system. 8M
Cont…2
2
Unit V
9. If you were about to create an index on a relation, what considerations would guide
your choice? Discuss:
i. The choice of primary index
ii. Clustered versus unclustered indexes
iii. Hash versus tree indexes
10M
Suppose that you have a sorted file and want to construct a dense primary tree index
on this file. One way to accomplish this task is to scan the file, record by record,
inserting each one using the tree insertion procedure. What performance and storage
utilization problems are there with this approach?
5M
10. Explain the difference between Hash indexes and B+-tree indexes. 10M
Discuss the concept of data Stripping. 5M