Relational model MCQs in DBMS

1. Who is credited with the creation of the relational database model?

(A) Edgar F. Codd

(B) Charles Bachman

(C) Larry Ellison

(D) James Gosling

2. In the relational model, data is organized into:

(A) Trees

(B) Graphs

(C) Tables

(D) Arrays

3. What is the primary key in a relational database?

(A) A unique identifier for each row in a table.

(B) A non-unique column.

(C) A key that can have null values.

(D) A foreign key.

4. In a relational database, what is a foreign key?

(A) A key that uniquely identifies a row.

(B) A key that points to a primary key in another table.

(C) A non-unique identifier.

(D) A key that does not allow null values.

5. Which language is most commonly used to interact with relational databases?

(A) C++

(B) Python

(C) SQL

(D) Java

6. In the relational model, a row is also known as a:

(A) Column

(B) Tuple

(C) Attribute

(D) Key

7. In the relational model, a column is also known as a:

(A) Tuple

(B) Relation

(C) Attribute

(D) Domain

8. What is a relation in the context of the relational database model?

(A) A table with rows and columns.

(B) A function that maps keys to values.

(C) A hierarchy of data.

(D) A network of connected nodes.

9. Which of the following is a characteristic of a relational database table?

(A) Each column has a unique name.

(B) Each row must have a unique key.

(C) Columns can have different data types.

(D) All of the above.

10. What is normalization in relational databases?

(A) The process of organizing data to reduce redundancy.

(B) The process of creating primary keys.

(C) The process of writing SQL queries.

(D) The process of creating foreign keys.

11. Which normal form eliminates all duplicate columns from the table?

(A) First Normal Form (1NF)

(B) Second Normal Form (2NF)

(C) Third Normal Form (3NF)

(D) Boyce-Codd Normal Form (BCNF)

12. In relational database terminology, a domain is:

(A) A set of allowed values for an attribute.

(B) A unique identifier for a table.

(C) A constraint that specifies the data type.

(D) A key used to establish relationships.

13. Which of the following constraints ensures that no two rows have the same value for a particular column?

(A) Primary Key

(B) Unique Key

(C) Foreign Key

(D) Not Null

14. Which SQL keyword is used to retrieve data from a database?

(A) SELECT

(B) UPDATE

(C) DELETE

(D) INSERT

15. A foreign key in a relational database is used to:

(A) Link two tables together.

(B) Uniquely identify a record within its own table.

(C) Ensure data integrity within a table.

(D) Specify a range of valid values.

16. What does ACID stand for in the context of databases?

(A) Atomicity, Consistency, Isolation, Durability

(B) Accuracy, Consistency, Integration, Durability

(C) Atomicity, Clarity, Isolation, Durability

(D) Accuracy, Clarity, Integration, Dependability

17. Which SQL statement is used to modify data in a database?

(A) SELECT

(B) UPDATE

(C) DELETE

(D) INSERT

18. Which of the following SQL clauses is used to filter the result set?

(A) FROM

(B) WHERE

(C) GROUP BY

(D) ORDER BY

19. The process of breaking down a complex table into simpler tables is called:

(A) Denormalization

(B) Normalization

(C) Structuring

(D) Indexing

20. In a relational database, a composite key is:

(A) A primary key composed of multiple columns.

(B) A foreign key that links multiple tables.

(C) A unique key that allows null values.

(D) A key that enforces data integrity.