Database Management Systems - Cochin University November 2009 Questions

Database Management Systems - Cochin University November 2009 Questions / CUSAT - DBMS Nov 2009 Question / CS 505 DBMS CUSAT Question

BTS (C) – V – 09 – 055 – G

B.Tech Degree V Semester Examination, November 2009

CS/IT 505 Database Management Systems

(2006 Scheme)

Time: 3 Hours                                                    Maximum marks: 100

PART – A

(Answer ALL Questions)

 (8 X 5 = 40)

I. (a) What is meant by data abstraction? How it helps to provide data independence?

(b) With suitable example, explain ‘partial key’ and ‘primary key’ concepts.

(c) Are tuples in a relation ordered? Why? What do you mean by domain of attributes?

(d) Describe the concept of functional dependencies with an example. When it will be trivial?

(e) Describe ACID properties of transactions. State its significance also.

(f) Explain the goals of data mining.

(g) Explain the technique ‘hashing’. Distinguish between internal and external hashing.

(h) Why do we use spanned records? Mention advantages and disadvantages.

PART – B

 (4 X 15 = 60)

II. (a) Explain the 3-schema architecture of database system. How it helps to achieve data independence? (7)

(b) Why do we use constraints in ER model? Describe various constraints. (6)

(c) When is super class/sub class relationship needed in data modeling?

OR

III. An University with various departments keep track of student details. Each ‘department’ runs courses (with unique course#) and each ‘course’ is divided into ‘sections’. Each section has a (coordinator, semester, year, course). Grade reports are supplied to students. Design an ER schema for this, supplying necessary attributes. Draw ER diagram and specify key attributes of each entity type and structural constraints on each relationship. (15)

IV. (a) When does collision occur in hashing? What are the resolution methods? (5)

(b) Why do we use ‘indexes’ in file access? (2)

(c) Explain any two single level ordered indexes. (8)

OR

V. (a) What is ‘mixed file’? Write difference between fixed length and variable length records. (5)

(b) Explain any two dynamic hashing techniques. (10)

VI. (a) A company database is given below;

          EMPLOYEE (NAME, ENO, DOB, SALARY, SEX, SUPERENO, DNO)

          DEPARTMENT (DNAME, DNUMBER, MGRENO, STRTDATE)

          DEPTLOCATIONS (DNUMBER, DLOCATIONS)

          PROJECT (PNUMBER, PLOCATION, DNUM)

          WORKS-ON (EENO, PNO, HOURS)

Write the following queries in SQL;

          (i) Retrieve all employees in department 1 whose salary is between 25,000 and 40,000.

          (ii) Get a list of employees and projects they are working on, ordered by department.

          (iii) For each employee, get the name and address of the manager.

          (iv) Get DOB and address of employees with name ‘James’. (8)

(b) Explain the use of various ‘JOIN’ operators in relational algebra. (3)

(c) Describe first 3 normal forms with examples. (4)

OR

VII. (a) Discuss various relational model constraints. (10)

(b) What is the need for high level data model? (2)

(c) Write the difference between ‘left outer join’ and ‘right outer join’ operations. (3)

VIII. (a) What are the problems associated with uncontrolled concurrent transactions? (6)

(b). Explain any two concurrency control techniques. (9)

OR

IX. (a) Discuss the relation of data mining to knowledge discovery. (7)

(b) Write short notes on object oriented databases and active databases. (8)

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