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MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION

(Autonomous)

(ISO/IEC - 27001 - 2005 Certified)

SUMMER 2019 EXAMINATION

MODEL ANSWER

Subject: Principles of Database Subject Code: 22321

Important Instructions to examiners:

1) The answers should be examined by key words and not as word-to-word as given in the model

answer scheme.

2) The model answer and the answer written by candidate may vary but the examiner may try to

assess the understanding level of the candidate.

3) The language errors such as grammatical, spelling errors should not be given more Importance

(Not applicable for subject English and Communication Skills).

4) While assessing figures, examiner may give credit for principal components indicated in the

figure. The figures drawn by candidate and model answer may vary. The examiner may give

credit for any equivalent figure drawn.

5) Credits may be given step wise for numerical problems. In some cases, the assumed constant

answer.

6) In case of some questions credit may be given by judgement on part of examiner of relevant

ding.

7) For programming language papers, credit may be given to any other program based on

equivalent concept.

Q.

No

.

Sub

Q.N.

Answer Marking

Scheme

1.

(a)

Ans.

Attempt any FIVE of the following:

List any four DBMS softwares.

(Note: Any four valid DBMS software can be considered)

List of DBMS software are the followings:

i. Oracle RDBMS

ii. IBM DB2

iii, Microsoft SQL Server

iv. MySQL

v. MS Access

vi. SQLite

vii. PostgreSQL

viii. MongoDB

ix. SQL Developer

x. SAP Sybase SE

10

2M

Any

four

1/2

M

each

(b)

Ans.

Define Domain and Attribute.

A Domain is defined as the set of all unique values permitted for an

attribute.

Attributes are the descriptive properties owned by each entity of an

2M

Each

definitio

n 1M

Page 2 of 20

MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION

(Autonomous)

(ISO/IEC - 27001 - 2005 Certified)

SUMMER 2019 EXAMINATION

MODEL ANSWER

Subject: Principles of Database Subject Code: 22321

entity set. each

(c)

Ans.

List and draw any four symbols used in ER-Model.

Different symbols used in ER-Model are the following:

2M

Any

four

symbol

1/2

M

each

(d)

Ans.

Define Constraint.

Constraints are the rules enforced on the data columns of a table.

These are used to limit the type of data that can go into a table. This

ensures the accuracy and reliability of the data in the database.

Constraints could be either on a column level or a table level. The

column level constraints are applied only to one column, whereas the

table level constraints are applied to the whole table.

2M

Definitio

n 2M

(e)

Ans.

Define Database. List any two advantages of database system.

A database is an organized collection of data so that it can be easily

accessed, managed and updated.

Advantages of database system are the following:

1. Controlling Redundancy of data in a centralized system of

DBMS

2. Integrity of data can be enforced in case of database system by

enforcing constraints

2M

Definitio

n 1M

Any two

advanta

ges

1/2

M

each

Page 3 of 20

MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION

(Autonomous)

(ISO/IEC - 27001 - 2005 Certified)

SUMMER 2019 EXAMINATION

MODEL ANSWER

Subject: Principles of Database Subject Code: 22321

3. Inconsistency of data can be avoided by reducing duplicacy or

redundancy

4. Data can be shared by multiple applications in centralized DBMS

5. Standards can be enforced in DBMS is a central system by

enforcing standards easily at Company level, Department level,

National level or International level.

6. Restricting unauthorized access among multiple users when

sharing of data takes place in a database.

7. Providing Backup and Recovery facilities is provide by DBMS

for recovering from hardware or software failures.

(f)

Ans.

Define database model.

Definition of database model:

A database model is a type of data model that determines the logical

structure of a database. It also fundamentally determines in which

manner data can be stored, organized and manipulated.

2M

Definitio

n 2M

(g)

Ans.

List advantages of Normalization.

List of Advantages of Normalization are the following:

1. More efficient data structure.

2. Avoid redundant fields or columns.

3. More flexible data structure i.e. we should be able to add new rows

and data values easily

4. Better understanding of data.

5. Ensures that distinct tables exist when necessary.

6. Easier to maintain data structure i.e. it is easy to perform operations

and complex queries can be easily handled.

7. Minimizes data duplication.

8. Close modeling of real world entities, processes and their

relationships.

2M

Any two

advanta

ges 1M

each

2.

(a)

Ans.

Attempt any THREE of the following:

Define data abstraction. Explain the levels of data abstraction

with neat diagram.

Data abstraction is defined as

Suppression of details of data organization and storage

Highlighting of the essential features for an improved

understanding of data

The characteristic that allow program data independence and

program operation independence is called data abstraction.

12

4M

Definitio

n 1M