Sunday, March 29, 2015

Database Management Systems University Question 7

Database Management Systems University Question 7

Database Management Systems

Time : Three Hours                                                                          Max.Marks:100
Answer ALL Questions
(10 X 10 = 100 Marks)

1. a) Define the following terms: database catalog ,program-data independence, canned transaction, deductive database system, meta-data. [5]
b) Discuss the main characteristics of the database approach and how it differs from traditional file systems. [5]

2. a) Describe the three-schema architecture. Why do we need mappings between schema levels? How do different schema definition languages support this architecture? [4]
b) Write a short note on component modules of an DBMS with neat diagram. [6]

3. a) Define the following terms: relation schema, relation state, degree of a relation. [3]
b) List the characteristics of relations that make them different from ordinary tables and files. [3]
c) Discuss the entity integrity and referential integrity constraints. Why each is considered important? [4]

4. a) List any two operations of relational algebra and the purpose of each. [4]
b) Student (snum: integer, sname: string, major: string, level: string, age: integer)
Class (name: string, meets at: string, room: string, fid: integer)
Enrolled (snum: integer, cname: string)
Faculty (fid: integer, fname: string, deptid: integer)
The meaning of these relations is straightforward; for example, Enrolled has one record per student-class pair such that the student is enrolled in the class. [6]
Write the following queries in SQL. No duplicates should be printed in any of the Answers.
i) Find the names of all Juniors (level = JR) who are enrolled in a class taught by particular Teacher.
ii) Find the age of the oldest student who is either a History major or enrolled in a course taught by I.Teach.
iii) Find the names of all classes that either meet in room R128 or have five or more students enrolled.

Figure 1 - ER Diagram for question 5
a) Explain the various steps of ER-to-Relational mapping algorithm. [7]
b) Write the relational schema for the above ER conceptual schema diagram for the COMPANY database. [3]

6. Suppose you are given a relation R = (A, B, C, D, E) with the following functional dependencies: {CE → D, D → B,C → A}.
a) Find all candidate keys. [4]
b) Identify the best normal form that R satisfies (1NF, 2NF, 3NF, or BCNF). [2]
c) If the relation is not in BCNF, decompose it until it becomes BCNF. At each step, identify a new relation, decompose and re-compute the keys and the normal forms they satisfy. [4]

7. a) Define the following terms [4]
i) Dense index ii) Sparse index iii) Index sequential file iv) Multilevel indices.
b) Explain the structure B+ Tree and illustrate update operations with examples. [6]

8. Explain the Heuristics query optimization techniques with example. [10]

9. a) List the various modes of lock and their uses. [3]
b) write a short note on [7]
i) Two phase locking protocol
ii) Graph-Based protocol

10. a) State the types of failures that may occur in a system. [3]
b) Explain log based recovery with respect to Deferred Database Modification and Immediate Database modifications. [7]


Featured Content

Multiple choice questions in Natural Language Processing Home

MCQ in Natural Language Processing, Quiz questions with answers in NLP, Top interview questions in NLP with answers Multiple Choice Que...

All time most popular contents

data recovery