Database Management System : Mid Semester Examination ( 4th Sem )

Database Management System

Mid Semester Examination, 2021-22
B. Tech - Semester : 04
Time : 1.30 hrs. - Max. Marks : 40

Instructions:

1. All questions are Compulsory
2. Assume missing data suitably, if any.

Section : A ( 2 x 2 = 4 Marks )

All questions are compulsory

1. What is data independence ? Differentiate between physical and logical data independence.
2. List out the notations of E-R diagram and their meaning.

Section : B ( 4 x 2 = 8 Marks )

All questions are compulsory

1. Differentiate between file processing system and DBMS.
2. Differentiate between strong and weak entity set with an example.

Section : C ( 6 x 2 = 12 Marks )

All questions are compulsory

1. Define foreign key ? Discuss Referential Integrity constraint with an example.
   
   -----OR-----
   Explain the term DBA and role of Database Administrator.
2. Construct an ER Diagram for an employee payroll system.
   
   -----OR-----
   Construct an ER Diagram for a hospital with a set of patients and a set of medical doctors. Associate with each patient, a log of the various tests and examinations conducted.

Section : D ( 8 x 2 = 16 Marks )

All questions are compulsory

1. Explain the 3-tier schema architecture of DBMS.
   
   -----OR-----
   Explain the following:
   i) Data Abstraction
   ii) DML
   iii) DDL
   iv) Specialization
2. Consider the following database schema:
   Student (St_id, Name),
   Enrolled_In (St_id, Sub_code),
   Subject (Sub_code, Lecturer)
   Express the following queries in Relational Algebra:
   i) What are the names of students taking a subject taught by Roger?
   ii) What are the names of students who are taking a subject not taught by Roger?
   iii) Who teaches CSI500?
   
   -----OR----
   In the context of a relational model, discuss each of the following concepts:
   i) Relation
   ii) Candidate Key
   iii) Primary Key
   iv) Cardinality

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