RGPV Previous Exam Papers Database Management System Dec 2006

RGPV Previous Exam Papers

Database Management System Dec 2006


Note:  Attempt any five questions. All question carry equal marks.

1. (a)    What are the responsibilities of DBA ? Explain .

(b)    Write difference between the following  :

(i)     Logical and physical data independence

(ii)    Database and physical data independence

2. (a)   Define and discuss main constraints on the following by giving example :

(i)     Specialization

(ii)     Generalization

(iii)   Aggregation

(b)   Draw an E-R diagram of university by determining entities of interest and the relationship that

Exist between these entities .

3. (a)   Explain the distinction between the representation of association and relationship in the network

And hierarchical models.

(b)   Explain about the following relational algebra operators by giving suitable example :

Union ,division,rename,difference

4.(a)   Consider the following Employee database :

Employee (Empname,street,City)

Work (Empname, company nameSalery)

Company  (Company ­­­name, city)

Manages (Emp name ,managers name)

Write expression in SQL and QUEL for the following queries :

(i)    Find all employees who live in the city where the company for which they work is located .

(ii)    Find all employees who live in the same city and on the same street as their managers.

(iii)    Find all employees in the database who do not work for ABC corporation .

(iv)    Find all employee names who earn more than every than every employee of ABC  corporation .

(v)     Find all company names located in every city in which ABC corporation is located.

5.(a)    Prove or disprove the following inference rules for functional dependencies :

(i)  { W → Y, X→Z }     |= { WX →Y}

(ii)  {X → Y} and Y > Z |={X → Z}

(iii) { X → Y, Y→Z}       |= {X→ YZ}

(iv) {X→Z , Y→Z}         |={X→Y}

(v)  { XY →Z, Z→W}    |= {X→W}

(b)     What are interface rules for multivalued  depencies ? Explain .

6.(a)     Describe NULL value and dangling tuple problems.

(b)     What is a canonical cover ? If

F={A→BC, CD → E, E →C,D→ AEH; ABH →BD, DH → BC }

Show that the non-redundant cover for F is

{ A→BC, E → C,D → AEH , ABH → BD}

7.(a)     What is serializability ? Write an algorithm for testing conflict serializabilty of a schedule .

(b)     Describe different types of transaction failure . What is meant by catastrophic failure ?

8.(a)     Write short notes on any two of the following :

(i) Various data models

(ii) Security and integrity constraints

(iii) Object- oriented database systems

(iv)  QBE

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