What is Database Indexing?

Database indexing is a technique used to speed up the retrieval of data from a database table. Indexes create data structures that improve query performance without scanning the entire table.

What are the different types of database indexes?

Common types of database indexes include single-column index, composite index, unique index, and full-text index. Each serves different use cases for query optimization.

Why is Database Indexing important?

Database indexing is important because it reduces query time, enhances search performance, and improves the scalability of applications by minimizing full table scans.

Database Indexing Interactive Demo

🚀 Search Performance Demo

Problem: Slow searches on a website! Without indexing, the database scans every record.

Search for a Product:

Performance Comparison:
Enter a product name and try both search methods to see the difference!

📚 Index Types Explorer

Insight: Different index types for different needs!

Index Types:
Click any index type to see its explanation and SQL examples!

📖 Book Index Analogy

📑

A book’s index page lists topics and their page numbers.

⚡

Database indexes work similarly—pointing to records directly.

🎯

Jump straight to the data without scanning every record!

🛒 Products Table and Index Management

🛒 Products Table (Sample Data)

ProductID	🔍 Name (Indexed)	🔍 Category (Indexed)	Price	Description
1	Soap	Personal Care	$0.60	Premium bathing soap with natural ingredients
2	Shampoo	Personal Care	$1.60	Anti-dandruff shampoo for healthy hair
3	Rice	Grocery	$1.10	Basmati rice 1kg pack premium quality
4	Oil	Grocery	$2.00	Mustard oil cold pressed organic
5	Papad	Snacks	$0.35	Crispy papad made from lentils

📋 Current Indexes

Index Name	Table	Columns	Type	Status
idx_product_name	Products	Name	Single Column	✅ Active
idx_category_price	Products	Category, Price	Composite	✅ Active
idx_product_id	Products	ProductID	Unique	✅ Active

Benefits of Indexes:
🔍 Name Index: Faster product searches
🧩 Composite Index: Quick filtering by category and price
⭐ Unique Index: Prevents duplicate ProductIDs

💻 SQL Commands for Index Management

/* Create Indexes */
-- Single Column Index
CREATE INDEX idx_product_name ON Products(Name);
-- Composite Index
CREATE INDEX idx_category_price ON Products(Category, Price);
-- Unique Index
CREATE UNIQUE INDEX idx_product_id ON Products(ProductID);
-- Full-Text Index
CREATE FULLTEXT INDEX idx_description ON Products(Description);

/* Manage Indexes */
-- View All Indexes
SHOW INDEX FROM Products;
-- Drop Index
DROP INDEX idx_product_name ON Products;
-- Check Index Usage
EXPLAIN SELECT * FROM Products WHERE Name = 'Soap';

📌 Best Practices for Indexing

Aspect	✅ Good Practice	❌ Bad Practice	Pro Tip
Column Selection	Index columns frequently used in searches or filters	Indexing every column	Index only where searches are frequent
Index Count	Create indexes thoughtfully	Too many indexes	More indexes can slow down INSERTs
Composite Indexes	Place the most selective column first	Random column order	Prioritize columns with unique values
Maintenance	Monitor and remove unused indexes	Ignoring index maintenance	Regularly check which indexes are used