# NPTEL Data Base Management System Assignment 1 Answers 2023

NPTEL Data Base Management System Assignment 1 Answers: 2023 – All the Answers provided below to help the students as a reference, You must submit your assignment at your own knowledge.

## NPTEL Data Base Management System Week 1 Assignment Answers 2023

1. Which of the following statements is (are) correct?

• a) Phsical level abstraction describes how a record is stored.
• b) View level abstraction hides details of data types.
• c) Physical level abstraction describes data stored in a database and their relationships.
• d) Logical level abstraction defines the physical schema.
`Answer :- a, b, `

2. Consider the following relations:

Subject (sid, sname, credit)
Faculty (fid, sid)
Which of the following is correct?

• a) RA1 C RAz
• b) RAg C RAg
• c) RAI C RAg
• d) RA1 = RAg
`Answer :- c) RAI C RAg`

3. What does the following Relational Algebra expression return?

• a) All heights except the maximum height from Mountain relation.
• b) All heights except the minimum height from Mountain relation.
• c) Minimum height from Mountain relation.
• d) Maximum height from Mountain relation.
`Answer :- d) Maximum height from Mountain relation.`

4. Consider the relational schema PhoneBook (Name, PhoneNo, Location, LastCalled)

• Ankit 3222265783 Kolkata 15 Jul
• Shreya 3222265783 Delhi 16 Jul
• Ankit 2222586110 Delhi 16 Jul
• Shreya 2222586110 Kolkata 15 Jul
`Answer :- c`

5. Consider the relation Flight (FlightNo, Source, Destination, Duration) where {FlightNo} and {Source, Destination, Duration} are the 2 candidate keys. What is the possible num- ber of superkeys of Flight?

• a) 8
• b) 9
• c) 10
• d) 16
`Answer :- b`

6. Consider a truth table having the following columns P Q R= ((P V Q) -P) S= ( (P V Q) – P) If the truth table, with all the values, is represented as a relational instance, which column(s) (attribute(s)) should be chosen as candidate keys?

• a) {P,R}
• b) {P,Q}
• c) {Q,R}
• d) {Q,S)
`Answer :- b, c`

7. Consider the following instance of ChatBox (SenderID, ReceiverID).

`Answer :- b`

8. Consider the following table:

`Answer :- d`

9. Consider the following table:

`Answer :- c`

10. Which of the following can be a candidate key for the following instance?

`Answer :- b`

## About Data Base Management System

Databases form the backbone of all major applications today – tightly or loosely coupled, intranet or internet based, financial, social, administrative, and so on. Structured Database Management Systems (DBMS) based on relational and other models have long formed the basis for such databases. Consequently, Oracle, Microsoft SQL Server, Sybase etc. have emerged as leading commercial systems while MySQL, PostgreSQL etc. lead in open source and free domain.

CRITERIA TO GET A CERTIFICATE

Average assignment score = 25% of average of best 6 assignments out of the total 8 assignments given in the course.
Exam score = 75% of the proctored certification exam score out of 100

Final score = Average assignment score + Exam score

YOU WILL BE ELIGIBLE FOR A CERTIFICATE ONLY IF AVERAGE ASSIGNMENT SCORE >=10/25 AND EXAM SCORE >= 30/75. If one of the 2 criteria is not met, you will not get the certificate even if the Final score >= 40/100.

You can find Data Base Management System Assignment 1 Answers below.

## NPTEL Data Base Management System Assignment 1 Answers July 2022

1. Identify the correct statement (s).

`Answer:- a`

2. A relation R has 2 candidate keys withl and 2 attributes respectively. There are 40 super keys of R. What is the total number of attributes in R?

a) 3
b) 4
c) 5
d) 6

`Answer:- d`

3. Which of the following relational operations will produce the following tuple only?

a) (QB1 U QB2) x (QB2 U QB1)
b) (QB1-QB2) n (QB2 QB1)
c) (QB1 QB2) x (QB2 QB1)
d) (QB1 n QB2) – (QB2 n QB1)

`Answer:- c`

4. Which of the following is a Secondary Key in CelestialReport?

a) {ReportBy, ReportScore}.

`Answer:- a, d`

5. Consider the following relational schema for a university:
student (roll.no, name, dob)
dept (deptNo, dName, location)
project (proj-no, deptNo, rOllno, pName)

What is the type of the key(s) that will be used to uniquely identify an entity of the project relation?

a) simple key
b) Alternate Key
C)Composite Key
d) Compound key

`Answer:- d`

6. ldentity the correct relational algebraic expression for the following query:

Find the names of students uho have selected any project offered by the department “CSE”.

a) ||name ( (student a project) bM lHdeptNo dName= “CSE” (dept) ))
b) ||name (aName=” “CSE” (dept project)) )
c) ||name (o dName=* “CSE” (student ba dept) ba (project) )
d) ||name (student ba (aName= “CSE” (project) ))

`Answer:- a`

7. ldentify the correct operation(s) which will produce the following output from the above two relations.

a) R1 R2
b) R2- -R1
c) (R1 UR2) n (Ri n Ra)
d) (R1-R2) U (Ra- R)

`Answer:- d`

8. ldentity the correct operation(s) which produces the following output from the above relation.

a) ||(YEAR_PUB=2010) v (TOTAL SOLD_COPIES >15000) (BookDetalls)
b) ||YEARPUB=2010) A (TOTAL.SOLD.cOPIES > 15000) (BookDetails)
c) (YEAR_PUB=2010) v (TOTAL SOLD COPIES > 15000) (BookDetails)
d) (YEARPUB=2010) (TOTAL SOLD.COPIES > 15000) (BookDetails)

`Answer:- For Answer Click Here`

9. Consider the following instannce:

`Answer:- b`

10. Which of the following can be a candidate key for the following instance?

a) (BOOKID, YEAR PUB}
b) {BOOK_ID, BOOK TITLE}
c) {BOOKTITLE, AUTHOR NAME}
d) {B0OK_ID}

`Answer:- c, d`

NPTEL Data Base Management System Assignment 1 Answers 2022: All the Answers provided below to help the students as a reference, You must submit your assignment at your own knowledge.

## NPTEL Data Base Management System Assignment 1 Answers Jan 2022

Q1. Identify the correct statement(s) from the following.

a) The overall physical structure of the database is called physical schema.
b) The actual content of the database at a particular point in time is called an instance.
c) Data dictionary does not contain any database schema.
d) Physical schema describes how data is stored in the database and the relationships among the data.

Q2. Consider the following instance:

Identify the correct representation of MLDatabase schema.

a) MLDatabase (Model, Accuracy. Dataset, TrainingData).
b) MLDatabase (Model, Accuracy, Datanet, TrainingData).
c) MLDatabase (Model, Accuracy, Dataset, TrainingData).
d) MLDatabase (Model, Accuracy, Dataset, TrainingData).

Q3. Identify the incorrect statement(s).

a) A Super Key is a set of one or more attributes that, taken collectively, allows us to uniquely identify an entity in the entity set.
b) A proper subset of a candidate key is called a Super Key.
c) The minimal set of attributes that allows us to uniquely identify an entity in the entity set is called a candidate key.
d) A proper subset of a Super Key is not always a Candidate Key.

Q4. Consider two relations below. The primary keys are underlined. Identify all possible foreign key (s) from the options.
Employee (EmpID, Enano, Salary) where EmpID is of type integer, Ename is of type string. and Salary is of type decimal number.
Project (EmpID, Pnumber) where ExpID is of type integer, and Pnumber is of type string.

a) Ename
b) EmpID
c) Paunber
d) EmpID, Pnumber

Q5. Consider the following instance of ImageRec (31. DepthImage, Coordi, Coord2))

Which of the following is a Secondary Key in InageRec?

a) (S1. Depth Image).
b) (Coord1, Coord2).
c) (Coord2, DepthImage).
d) (Coord1. DepthImage).

Q6. Consider the following instances:

How many tuples will be selected by aplayer=Gamer (Game1 x Game2)?

a) 3
b) 4
c) 8
d) 9

Q7. Consider the two tables given below.

Identify the correct statement from the following.

a) Cartesian product of Student and Teacher has six tuples
b) Cartesian product of Student and Teacher is not possible.
c) There will be three tuples in the result of the natural join between Student and Teacher.
d) Natural Join between Student and Teacher is not possible.

Q8. Consider the following table:

Identify the correct operation(s) which produces the following output from the above relation.

b) II (Branch-Address) v (Salary>10000) (EmployeeDetails)

Q9. Consider the following tables:

Identify the correct operation(s) which will produce the following output from the above two relations.

a) R₁-R₂
b) R2-R1
c) (R1UR₂) ∩ (R1∩R₂)
d) (R1-R₂) U (R₂-R₁)

Q10. Which of the following can be a candidate key for the following instance?

a) {EmpName}
b) (Branch)
d) (Emplame, Branch)

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NPTEL Data Base Management System Assignment 1 Answers:- All the Answers provided below to help the students as a reference, You must submit your assignment at your own knowledge.