1. Question 1

Purpose of a foreign key in a relational database?

• ✅ To create a link between two tables

• ❌ Ensure data integrity within a single table

• ❌ Represent a unique identifier

• ❌ Store the primary key of a table

Explanation:
A foreign key connects one table to another, enforcing relational integrity between them.

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2. Question 2

Best data type for storing a book title?

• ❌ Integer

• ❌ Decimal

• ❌ Date

• ✅ Char

Explanation:
Book titles are text values → stored using CHAR/VARCHAR data types.

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3. Question 3

Core objective of a relational database?

• ❌ Perform complex searches

• ❌ Eliminate data redundancy

• ❌ Store unstructured data

• ✅ Organize data into tables based on common attributes

Explanation:
Relational databases structure data into tables with relationships based on shared attributes.

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4. Question 4

Purpose of an index?

• ❌ Enforce referential integrity

• ✅ Speed up query performance

• ❌ Eliminate redundancy

• ❌ Store binary data

Explanation:
Indexes improve search efficiency by allowing fast lookup of data.

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5. Question 5

Primary characteristic of database permissions?

• ❌ Only allow creating databases

• ❌ Only system-level

• ✅ Enable user access to a specific database or table

• ❌ Only granted by administrator

Explanation:
Permissions control which users can access which database objects (tables, views, etc.).

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6. Question 6

Non-relational databases are also known as:

• ✅ NoSQL databases

• ❌ Hierarchical databases

• ❌ Flat files

• ❌ SQL databases

Explanation:
Non-relational systems (key-value, document, graph, column stores) are categorized as NoSQL.

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7. Question 7

Primary benefit of non-relational databases?

• ✅ Speed, flexibility, and scale for big data

• ❌ Predefined schema

• ❌ Optimized for tabular data

• ❌ Ensure redundancy

Explanation:
NoSQL databases handle massive, unstructured, or semi-structured data with high scalability.

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8. Question 8

What are entities in ER model?

• ❌ Always drawn as ovals

• ❌ Used to design relational databases (true but not best answer)

• ✅ Objects that exist independently in the database

• ❌ Represent relationships

Explanation:
An entity is a real-world object (Person, Product, Order) with attributes.

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9. Question 9

Standard language for querying relational databases?

• ❌ JavaScript

• ✅ SQL

• ❌ Python

• ❌ HTML

Explanation:
SQL is the universal language for relational database operations.

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10. Question 10

Example of a non-relational database:

• ❌ MySQL

• ✅ MongoDB

• ❌ PostgreSQL

• ❌ SQLite

Explanation:
MongoDB is a document-based NoSQL database.

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🧾 Summary Table

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