computer MCQs - 12th class Chapter 04 Mcqs

1

What does database integrity primarily refer to?

A

The speed of data access

B

The correctness and consistency of data

C

The security from unauthorized access

D

The physical size of the database

2

Which constraint states that no attribute of a primary key should contain nulls?

A

Referential Integrity

B

Domain Integrity

C

Entity Integrity

D

User-defined Integrity

3

Normalization is the process of converting complex data structures into what kind of structures?

A

Encrypted structures

B

Hierarchical structures

C

Network structures

D

Simple and stable data structures

4

What is the basis for a relational database system according to the text?

A

Data Integrity

B

Functional Dependency

C

Normalization

D

Entity-Relationship Diagrams

5

A functional dependency is a particular relationship between two what?

A

Relations

B

Tables

C

Attributes

D

Databases

6

In the functional dependency A -> B, what is attribute A called?

A

Dependent

B

Determinant

C

Key

D

Entity

7

What problem occurs when two different names are used for the same information or attribute?

A

Homonym

B

Redundant Information

C

Synonym

D

Mutually Exclusive Data

8

A homonym is created when the same name is used for what?

A

Two different entities

B

Two different attributes

C

The same attribute in two tables

D

Two different records

9

Storing the same information in two different ways, like 'Employee_Age' and 'D_O_Birth', is an example of what?

A

Synonym

B

Homonym

C

Mutually Exclusive Data

D

Redundant Information

10

Attributes with 'yes/no' or 'M/S' values are examples of what type of data issue?

A

Synonyms

B

Mutually Exclusive Data

C

Homonyms

D

Redundant Information

11

What is the first step in the normalization process, which removes repeating groups?

A

Achieving 2NF

B

Achieving 3NF

C

Achieving 1NF

D

Removing transitive dependencies

12

A relation is in First Normal Form (1NF) if and only if all underlying domains contain what kind of values?

A

Null values

B

Numeric values

C

Atomic values

D

String values

13

According to the text, what must all entities have, composed of one or more attributes that uniquely identify an occurrence?

A

A foreign key

B

A secondary key

C

A key

D

A determinant

14

In Case-1 (DEPARTMENT), having 'Emp_No' and 'Emp_Name' attributes that repeat for a single department is an example of what?

A

Partial dependency

B

Transitive dependency

C

Repeating groups

D

A composite key

15

What kind of relationship exists when one department has many employees, but each employee belongs to only one department?

A

M:N

B

1:1

C

M:1

D

1:M

16

In the case of Items and Orders, where each item can be in many orders and each order can have many items, what is the relationship type?

A

1:M

B

1:1

C

M:N

D

M:1

17

To solve the M:N relationship issue between ITEM and ORDER, what new entity was created?

A

ITEM_ORDERED

B

ORDER_DETAILS

C

PRODUCT_SALES

D

INVENTORY

18

A relation is in Second Normal Form (2NF) if it is in 1NF and what other condition is met?

A

There are no composite keys

B

Every non-key attribute is fully functionally dependent on the primary key

C

There are no functional dependencies

D

It has no foreign keys

19

What is the primary key in the STUDENT(STUD-ID,CRSNO,CDTE) relation before it is decomposed?

A

STUD-ID

B

CRSNO

C

STUD-ID + CRSNO

D

CDTE

20

When a non-key attribute is functionally dependent on part, but not all, of the primary key, it is called a what?

A

Transitive dependency

B

Full functional dependency

C

Partial functional dependency

D

Key dependency

21

An insertion anomaly in the context of the STUDENT table means we cannot add a new course without a what?

A

A student ID

B

A course date

C

A course fee

D

A department name

22

If deleting a student's last course record also removes the student's existence from the database, what is this anomaly called?

A

Insertion Anomaly

B

Modification Anomaly

C

Update Anomaly

D

Deletion Anomaly

23

To convert a relation to 2NF, we typically do what to the relation?

A

Add more attributes

B

Encrypt the data

C

Decompose the relation

D

Create more repeating groups

24

A relation is in Third Normal Form (3NF) if it is in 2NF and no what exists?

A

Partial dependencies

B

Primary keys

C

Transitive dependencies

D

Foreign keys

25

What is a transitive dependency?

A

A dependency between a key and a non-key attribute

B

A dependency between two key attributes

C

A functional dependency between two or more non-key attributes

D

A dependency on a foreign key

26

In the SALES relation, REGION is functionally dependent on SALESMAN, which in turn is dependent on CUSTNO. This is an example of what?

A

Partial dependency

B

Transitive dependency

C

Entity integrity

D

Referential integrity

27

The primary key in the SALES(CUSTNO, NAME, SALESMAN, REGION) relation consists of how many attributes?

A

Two

B

Three

C

One

D

Four

28

What anomaly occurs in the SALES relation if you cannot add a new salesman until they are assigned a customer?

A

Deletion Anomaly

B

Modification Anomaly

C

Insertion Anomaly

D

Update Anomaly

29

How is the transitive dependency problem in the SALES relation removed?

A

By adding a new key

B

By deleting the REGION attribute

C

By decomposing it into two relations: SALE1 and SMAN

D

By converting it to 1NF

30

In the decomposed SMAN(SALESMAN, REGION) relation, what does the SALESMAN attribute become?

A

A foreign key

B

A non-key attribute

C

A secondary key

D

The primary key

31

In a relational database, a table is also called a what?

A

Tuple

B

Relation

C

File

D

Schema

32

In 3NF, a non-key attribute must not depend on what?

A

The primary key

B

A foreign key

C

Another non-key attribute

D

A composite key

33

Every relation must have a what?

A

Primary key

B

Candidate key

C

Secondary key

D

Composite key

34

What term refers to a constraint on foreign key values?

A

Entity Integrity

B

Referential Integrity

C

Normalization

D

Functional Dependency

35

What is removed during the second stage of normalization (moving from 1NF to 2NF)?

A

Repeating Groups

B

Partial Dependencies

C

Transitive Dependencies

D

Anomalies

36

What is removed during the third stage of normalization (moving from 2NF to 3NF)?

A

Repeating Groups

B

Anomalies

C

Transitive Dependencies

D

Partial Dependencies

37

Security in a database is concerned with protecting data from what?

A

Data corruption

B

Inconsistency

C

Unauthorized operations

D

Slow performance

38

Integrity in a database is concerned with what?

A

The speed of queries

B

The quality of data itself

C

The user interface

D

The network connection

39

If a foreign key exists, it must either be null or match a value in its home relation's what?

A

Foreign key

B

Secondary key

C

Primary key

D

Sort key

40

The process of reviewing entity/attribute lists to ensure attributes are stored 'where they belong' is known as what?

A

Data security

B

Data validation

C

Normalization

D

Data mining

41

The attribute on the left-hand side of the arrow in a functional dependency is called the what?

A

Dependent

B

Determinant

C

Result

D

Object

42

Which of the following is NOT a problem to be checked before the normalization process begins?

A

Synonyms

B

Homonyms

C

Primary key existence

D

Redundant Information

43

In the example Employee(Employee_Age, D_O_Birth), why is having both attributes considered an error?

A

It is a synonym

B

It is a homonym

C

It is mutually exclusive

D

It is redundant information

44

What does 'atomic values' mean in the context of 1NF?

A

The values are very small

B

The values are indivisible

C

The values are numeric

D

The values are text-based

45

A key composed of a combination of one or more attributes is called what?

A

A simple key

B

A primary key

C

A candidate key

D

A composite key

46

What type of anomaly occurs if changing a single piece of data requires updating multiple rows?

A

Insertion Anomaly

B

Deletion Anomaly

C

Modification Anomaly

D

Structural Anomaly

47

The table STUDENT(STUD-ID, NAME, DEPT, MONFEE, CRSNO, CDTE) is not in 2NF because NAME, DEPT, and MONFEE are dependent on what?

A

Only on CRSNO

B

Only on STUD-ID

C

On both STUD-ID and CRSNO

D

On a non-key attribute

48

After decomposing the original STUDENT table to achieve 2NF, the attribute CDTE ends up in which new table?

A

STUDENT1

B

COURSE

C

A new third table

D

It is deleted

49

In the SALES relation, which attribute is the determinant in the transitive dependency?

A

CUSTNO

B

NAME

C

SALESMAN

D

REGION

50

The final step shown in the normalization process diagram on page 37 is to remove what?

A

Repeating Groups

B

Partial Dependencies

C

Remaining anomalies

D

Transitive Dependencies