Computer Science MCQS

Computer Science MCQ with detailed explanations for students & freshers preparing for entrance exams, various tests, interviews, competitive exams like GATE exam, interview, competitive examination and entrance exam.

The DBMS acts as an interface between ____ and ____ of an enterprise-class system.

A. a) Data and the DBMS
B. b) Application and SQL
C. c) Database application and the database
D. d) The user and the software
Correct answer is: C. c) Database application and the database
A DBMS acts as an interface between a database application and the database.

Here's a breakdown:

Database Application: This is the software that interacts with the user and provides a way to access and manipulate the data in the database. Examples include accounting software, inventory management systems, or customer relationship management (CRM) tools.

Database: This is the underlying storage structure that holds the data. It's where the information is physically stored.

Role of the DBMS:

Translation: The DBMS translates requests from the application into operations that the database can understand.

Data Management: It handles tasks like data storage, retrieval, updating, and deletion.

Security: It ensures data integrity, security, and concurrency control.

By acting as this intermediary, the DBMS simplifies the process for application developers and users, allowing them to focus on their specific needs without worrying about the complexities of data management.

__ is a hardware component that is most important for the operation of a database management system.

A. a) Microphone
B. b) High speed, large capacity disk to store data
C. c) High-resolution video display
D. d) Printer
Correct answer is: B. b) High speed, large capacity disk to store data
A high-speed, large capacity disk is the most critical hardware component for a database management system (DBMS).

Here's why:

Data Storage: A DBMS is designed to store and manage vast amounts of data. A large capacity disk provides the necessary space to accommodate the growing database.

Performance: High-speed disks enable rapid data access and retrieval. This is essential for efficient database operations like querying, updating, and deleting data.

Reliability: Databases often contain critical information. A reliable disk ensures data integrity and prevents data loss.

While other components like a monitor, printer, or microphone are important for interacting with the DBMS, they are not as critical to its core functionality as the disk.

Therefore, option b) is indeed the correct answer.

What does an RDBMS consist of?

A. a) Collection of Records
B. b) Collection of Keys
C. c) Collection of Tables
D. d) Collection of Fields
Correct answer is: C. c) Collection of Tables
A foreign key is a column (or a set of columns) in one table that refers to the primary key of another table. It establishes a link between the two tables, ensuring data consistency and integrity.  

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Imagine this:

You have a table called "Customers" with columns like "Customer ID", "Name", "Address".

You have another table called "Orders" with columns like "Order ID", "Customer ID", "Order Date", "Total Amount".

The "Customer ID" in the "Orders" table is a foreign key. It references the "Customer ID" in the "Customers" table. This means that every order must be associated with an existing customer.

Key points about foreign keys:

It maintains referential integrity, ensuring that related data exists.

It helps to normalize data by reducing redundancy.

It allows you to retrieve related data efficiently through joins.

By using foreign keys, you create a structured and connected database where information can be easily managed and retrieved.

What is information about data called?

A. a) Hyper data
B. b) Tera data
C. c) Meta data
D. d) Relations
Correct answer is: C. c) Meta data
Primary Key

A primary key is a unique identifier for a record in a database table.

Imagine a table of students. Each student has a unique student ID number. This student ID would be the primary key because it uniquely identifies each student record.

Key characteristics of a primary key:

Unique: No two records can have the same primary key value.

Not Null: Every record must have a primary key value.

Minimal: It should contain only the necessary columns to uniquely identify a record.

Purpose:

To efficiently locate specific records.

To establish relationships between tables (foreign keys).

To maintain data integrity.

By using primary keys, a database system can quickly find, update, or delete specific records without confusion or errors.

Which of the following is known as a set of entities of the same type that share same properties, or attributes?

A. a) Relation set
B. b) Tuples
C. c) Entity set
D. d) Entity Relation model
Correct answer is: C. c) Entity set
n entity set is a collection of entities that share the same characteristics or attributes. Think of it as a group of similar things.

For example, if we're talking about a university database, an entity set could be "Students". All students share common attributes like student ID, name, address, etc.

So, the correct answer is c) Entity set.

Which of the following is a component of the DBMS?

A. a) Data
B. b) Data Languages
C. c) Data Manager
D. d) All of the above
Correct answer is: D. d) All of the above
A Database Management System (DBMS) is composed of several essential components that work together to manage data efficiently. Let's break down each option:

Data: This is the core of any database. It refers to the information stored within the system.

Data Languages: These are special languages used to interact with the database. They include:

DDL (Data Definition Language): For creating and modifying database structures.

DML (Data Manipulation Language): For inserting, updating, deleting, and retrieving data.

DCL (Data Control Language): For granting and revoking user permissions.

Data Manager: This is the software component that handles the overall management of the database. It ensures data integrity, security, and efficient access.

As you can see, all three components are integral parts of a DBMS. Therefore, the correct answer is d) All of the above.

A DBMS would be incomplete without any of these elements. They work in harmony to provide a robust and reliable system for managing data.

Which of the following is a function of the DBMS?

A. a) Storing data
B. b) Providing multi-users access control
C. c) Data Integrity
D. d) All of the above
Correct answer is: D. d) All of the above
A Database Management System (DBMS) is essentially a software application that interacts with the user, applications, and the database itself to capture and analyze data.

Its primary functions encompass:

Storing data: This is the fundamental role of a DBMS. It efficiently manages and organizes large volumes of data in a structured format, making it accessible when needed.

Providing multi-user access control: A DBMS ensures that multiple users can access and manipulate data simultaneously without conflicts or compromising data integrity. It implements security measures to protect data from unauthorized access.

Data Integrity: A DBMS maintains data consistency and accuracy by enforcing rules, constraints, and validation checks. It prevents errors, inconsistencies, and data loss.

Since all three options (storing data, providing multi-user access control, and data integrity) are core functions of a DBMS, the correct answer is d) All of the above.

In essence, a DBMS acts as a central repository for data, providing controlled access and ensuring its reliability.Sources and related content

Which of the following is not a function of the database?

A. a) Managing stored data
B. b) Manipulating data
C. c) Security for stored data
D. d) Analysing code
Correct answer is: D. d) Analysing code
Databases are designed to handle data, not code. They excel at:

Storing: Keeping information organized and readily available.

Managing: Allowing efficient access, retrieval, and modification of data.

Securing: Protecting sensitive information through access control and encryption.

Analyzing code, on the other hand, is typically done by specialized software tools or programming languages.

Which of the following is a feature of the database?

A. a) No-backup for the data stored
B. b) User interface provided
C. c) Lack of Authentication
D. d) Store data in multiple locations
Correct answer is: B. b) User interface provided
User interface provided is a feature of a database.

A user interface allows users to interact with the database to perform tasks like searching, adding, modifying, or deleting data.

Which of the following is not a feature of DBMS?

A. a) Minimum Duplication and Redundancy of Data
B. b) High Level of Security
C. c) Single-user Access only
D. d) Support ACID Property
Correct answer is: C. c) Single-user Access only
Single-user access only is NOT a feature of DBMS.

DBMS systems are designed to handle multiple users accessing and manipulating data simultaneously. This is a core functionality.

Here's a breakdown of the other options:

Minimum Duplication and Redundancy of Data: DBMS ensures data integrity by preventing data duplication and redundancy.

High Level of Security: DBMS provides mechanisms to protect data from unauthorized access.

Support ACID Property: ACID (Atomicity, Consistency, Isolation, Durability) is a fundamental property of transaction management in DBMS, ensuring data integrity.

Therefore, single-user access only is the outlier and not a feature of DBMS.

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