Que. 1: Which of the following statements is (are) incorrect? a) Logical level abstraction defines the physical storage of data. b) View level abstraction provides a user-friendly interface for end users. c) Physical level abstraction focuses on the relationships among data. d) Logical level abstraction focuses on the relationships among data.
Answers: Updating soon (in progress).
Que. 2: Consider the following SQL statements:
sqlCopyEditINSERT INTO emp_name, dept)
VALUES (101, 'Alice', 'HR');
ALTER TABLE employees ADD count salary number(8, 2);
Identify the correct statement. a) Both S1 and S2 are Data Manipulation (DML) Queries. b) S1 is a Data Manipulation (DML) Query, and S2 is a Data Definition (DDL) Query. c) Both S1 and S2 are Data Definition (DDL) Queries. d) S1 is a Data Control Query, and S2 is a Data Definition (DDL) Query.
Answers: Updating soon (in progress).
Que. 3: Identify the valid primary key for the relation event_registration from the given instance:
participant_id
event_id
registration_date
status
1001
E001
2024-01-10
Confirmed
1002
E002
2024-01-11
Pending
1003
E001
2024-01-10
Confirmed
1004
E003
2024-01-12
Confirmed
1001
E002
2024-01-14
Pending
a) participant_id. b) event_id, registration_date. c) participant_id, event_id. d) event_id, status.
Answers: Updating soon (in progress).
Que. 4: Identify the correct statement(s): a) Employee(empID, empName) is an instance of a relation schema. b) Employee(empID, empName) is an example of a physical schema. c) (101, John) is an instance of a relation schema. d) (101, John) is an example of a logical schema.
Que. 5: Consider a relation CityDetails(CityName, Population, CountryName) where the superkeys are as follows: {CityName}, {CityName, Population}, {CityName, CountryName}, {CityName, Population, CountryName}.
Select the possible candidate key(s). a) {CityName, Population, CountryName}. b) {CityName, Population}. c) {CityName}. d) {CityName, CountryName}.
Answers: Updating soon (in progress).
Que. 6: Consider the following relations: Employee(eid, ename, salary), Department(dept_id, dept_name).
Consider the following Relational Algebras: RA1: πEmployee.eid, ename(Employee ⨝ Department). RA2: πEmployee.eid, ename(Employee × Department).
Which of the following is correct? a) RA1 = RA2. b) RA1 ⊂ RA2. c) RA2 ⊂ RA1. d) RA1 ≠ RA2.
Answers: Updating soon (in progress).
Que. 7: Consider the following instance of the CourseDetails (CourseID, CourseName) relation:
CourseID
CourseName
C101
Mathematics
C102
Physics
If CourseID is the foreign key in the relational schema StudentEnrollments (EnrollmentID, StudentName), which of the following is a valid instance of StudentEnrollments?
a)
EnrollmentID
CourseID
StudentName
E001
C105
Amit
E002
C102
Raj
b)
EnrollmentID
CourseID
StudentName
E001
C102
Amit
E001
C102
Raj
c)
EnrollmentID
CourseID
StudentName
NULL
C102
Amit
E003
C102
Raj
d)
EnrollmentID
CourseID
StudentName
E001
C102
Amit
E002
C102
Raj
Answers: Updating soon (in progress).
Que. 8: Identify the correct operation(s) to produce the following output:
Given table CityDetails:
CityName
Population
StateName
Mumbai
20000
Maharashtra
Delhi
19000
Delhi
Bengaluru
12000
Karnataka
a) σ (CityDetails). b) σ (Population > 10000) ∧ (StateName = ‘Maharashtra’) (CityDetails). c) σ (StateName = ‘Delhi’) (CityDetails). d) π (CityDetails).
Answers: Updating soon (in progress).
Data Base Management System Nptel Assignment 1 Answers (Jul-Dec 2024)
These are Data Base Management System Nptel Assignment 1 Answers
Q1. Consider the SQL statement(s) below: S1: CREATE table students( student_id number(5), student_name varchar2(20), address varchar2(20), emailid varchar2(20)); S2: DELETE FROM students WHERE student_id = 10005; Identify the correct statement. a) Both S1 and S2 are Data Definition (DDL) Queries b) Both S1 and S2 are Data Manipulation (DML) Queries c) S1 is a Data Definition (DDL) Query and S2 is a Data Manipulation Query (DML) d) S1 is a Data Control Query and S2 is a Data Manipulation (DML) Query
These are Data Base Management System Nptel Assignment 1 Answers
Q3. Identify the correct statement/s. a) Logical schema defines the overall logical structure of the database. b) Logical schema defines the overall physical structure of the database. c) Physical schema defines the overall logical structure of the database. d) View schema defines the interaction between end-user and database.
Answer: a) Logical schema defines the overall logical structure of the database.
d) View schema defines the interaction between end-user and database.
Q4. Consider a relation MountainDetails (MountainName, Altitude, StateName) where the su- perkeys are as follows: (MountainName}, {MountainName, Altitude}, {MountainName, StateName}, {MountainName, Altitude, StateName). Select the possible candidate key(s). a) {MountainName, Altitude, StateName} b) {MountainName, StateName} c) {MountainName, Altitude} d) {MountainName}
These are Data Base Management System Nptel Assignment 1 Answers
Q5. Let students (student_id, student name, address, emailid) and enrolment (student_id, dept name, enrolment_date) be two relations in a schema. The primary keys are shown underlined. Let student_id be a foreign key in enrolment relation referring to students relation. Suppose, there is no violation of the above referential integrity constraint in the corresponding relation instances of students and enrolment. Which one of the following relational algebra expressions would necessarily produce an empty relation? a) Istudent_id (enrolment) Istudent_id (students) b) Istudent_id (students) Istudent_id (enrolment) c) Istudent_id(enrolment <> students) d) Istudent_id (enrolment students)
Q6.Which of the following statements is (are) correct? a) View level abstraction describes how a record is stored. b) View level abstraction hides details of data types and focuses on the interaction with the end-users. c) Logical level abstraction describes what data is stored in a database and their relationships. d) Physical level abstraction describes what data is stored in a database and their relationships.
Answer: b) View level abstraction hides details of data types and focuses on the interaction with the end-users. c) Logical level abstraction describes what data is stored in a database and their relationships.
These are Data Base Management System Nptel Assignment 1 Answers
Q7. Consider the following instance of the Student Details (StudentID, Student name) relation:
Answer : d)
Q8. Consider the following tables:
a) ChatDetails ChatDetails b) ChatDetails2 ChatDetailsı c) (ChatDetails ChatDetails₂) U (ChatDetails2 ChatDetails1) d) (ChatDetails₁ U ChatDetails₂) ∩ (ChatDetails ChatDetails2)
