Q.1 What is a database?
A collection of related data
A programming language
A type of operating system
A network protocol
Explanation - A database is an organized collection of data, generally stored and accessed electronically from a computer system.
Correct answer is: A collection of related data
Q.2 Which of the following is a popular relational database management system (RDBMS)?
MySQL
Python
HTML
Linux
Explanation - MySQL is one of the most widely used RDBMS which uses structured query language (SQL) for managing data.
Correct answer is: MySQL
Q.3 What does SQL stand for?
Structured Query Language
Simple Query List
Sequential Question Language
Standard Quick Language
Explanation - SQL is a standardized language used to query, insert, update, and manage data in relational databases.
Correct answer is: Structured Query Language
Q.4 Which type of database stores data in key-value pairs?
Relational database
NoSQL database
Hierarchical database
Network database
Explanation - NoSQL databases often store data as key-value pairs, documents, or graphs, which allows for flexible schemas.
Correct answer is: NoSQL database
Q.5 Which of the following is a characteristic of a relational database?
Data is stored in tables with rows and columns
Data is stored as unstructured files
Data is stored only in memory
Data cannot be queried
Explanation - Relational databases organize data into tables (relations) with rows (records) and columns (attributes).
Correct answer is: Data is stored in tables with rows and columns
Q.6 What is a primary key in a database table?
A unique identifier for each record
A key to open the database
A password for security
A foreign reference to another table
Explanation - A primary key uniquely identifies each record in a database table and ensures no duplicate entries.
Correct answer is: A unique identifier for each record
Q.7 Which operation is NOT part of CRUD in databases?
Create
Read
Update
Connect
Explanation - CRUD stands for Create, Read, Update, and Delete, which are basic operations performed on database records.
Correct answer is: Connect
Q.8 What is a foreign key in a database?
A field in one table that refers to the primary key in another table
A password for database access
A key used to encrypt data
A unique identifier within the same table
Explanation - Foreign keys are used to establish and enforce a link between the data in two tables.
Correct answer is: A field in one table that refers to the primary key in another table
Q.9 Which of these is an example of a NoSQL database?
MongoDB
Oracle
PostgreSQL
MS Access
Explanation - MongoDB is a NoSQL database that stores data in flexible, JSON-like documents rather than relational tables.
Correct answer is: MongoDB
Q.10 What is normalization in a database?
Organizing data to reduce redundancy
Increasing the size of the database
Encrypting the database for security
Backing up the database
Explanation - Normalization is the process of organizing data to minimize redundancy and improve data integrity.
Correct answer is: Organizing data to reduce redundancy
Q.11 Which command is used to retrieve data from a database in SQL?
SELECT
INSERT
UPDATE
DELETE
Explanation - The SELECT command is used to query and retrieve data from one or more tables in a database.
Correct answer is: SELECT
Q.12 In databases, what does ACID stand for?
Atomicity, Consistency, Isolation, Durability
Accuracy, Control, Integrity, Data
Access, Compute, Insert, Delete
Atomic, Correct, Indexed, Durable
Explanation - ACID properties ensure reliable processing of database transactions in relational databases.
Correct answer is: Atomicity, Consistency, Isolation, Durability
Q.13 Which type of database model organizes data in a tree-like structure?
Hierarchical database
Relational database
NoSQL database
Network database
Explanation - Hierarchical databases store data in a tree-like structure where each child has only one parent.
Correct answer is: Hierarchical database
Q.14 What is a database schema?
The structure that defines how data is organized
A type of database query
A backup copy of the database
A security protocol
Explanation - A database schema describes the tables, fields, relationships, and constraints in a database.
Correct answer is: The structure that defines how data is organized
Q.15 Which SQL statement is used to add new data to a table?
INSERT INTO
SELECT FROM
UPDATE
DELETE FROM
Explanation - The INSERT INTO statement is used to add new rows (records) into a database table.
Correct answer is: INSERT INTO
Q.16 Which of the following is NOT a type of database?
Relational
Hierarchical
Network
Compiler
Explanation - A compiler is a program that translates code, not a database type. Databases include relational, hierarchical, and network types.
Correct answer is: Compiler
Q.17 Which operation in SQL is used to remove records from a table?
DELETE
DROP
TRUNCATE
REMOVE
Explanation - The DELETE statement removes specified rows from a table while preserving the table structure.
Correct answer is: DELETE
Q.18 Which SQL statement is used to change existing data in a table?
UPDATE
INSERT
SELECT
CREATE
Explanation - The UPDATE statement modifies existing records in a table based on specified conditions.
Correct answer is: UPDATE
Q.19 Which of the following best describes a database management system (DBMS)?
Software that manages and organizes databases
Hardware for storing databases
A type of programming language
A network protocol
Explanation - A DBMS is software that enables users to define, create, maintain, and control access to databases.
Correct answer is: Software that manages and organizes databases
Q.20 Which of the following is a common feature of modern DBMS?
Data security and backup
Automatic hardware installation
Web browser creation
Email sending
Explanation - Modern DBMS provide security, backup, and recovery mechanisms to ensure data integrity and availability.
Correct answer is: Data security and backup
Q.21 Which type of database is most suitable for handling large amounts of unstructured data?
NoSQL database
Relational database
Hierarchical database
Flat-file database
Explanation - NoSQL databases are designed to efficiently store and process large volumes of unstructured or semi-structured data.
Correct answer is: NoSQL database
Q.22 What is a database index used for?
To improve the speed of data retrieval
To store passwords
To create backups
To connect databases
Explanation - An index is a database structure that improves the performance of query operations by allowing faster access to rows.
Correct answer is: To improve the speed of data retrieval
Q.23 Which of these is an example of a cloud-based database service?
Amazon RDS
MySQL on local server
MS Access desktop
SQLite on local machine
Explanation - Amazon RDS is a cloud-based relational database service that simplifies setup, operation, and scaling of databases.
Correct answer is: Amazon RDS
Q.24 Which of the following ensures that a database transaction is completed fully or not at all?
Atomicity
Normalization
Indexing
Partitioning
Explanation - Atomicity is an ACID property that ensures a transaction is treated as a single unit, which either fully succeeds or fails.
Correct answer is: Atomicity