Indexing Strategies

Indexes are crucial for database performance. They speed up data retrieval but require careful planning.

What is an Index?

An index is a data structure that improves the speed of data retrieval operations on a database table.

Creating Indexes

CREATE INDEX idx_customer_email ON customers(email);

Types of Indexes

Single Column Index

Index on one column:

CREATE INDEX idx_title ON books(title);

Composite Index

Index on multiple columns:

CREATE INDEX idx_name ON customers(last_name, first_name);

Unique Index

Ensures uniqueness:

CREATE UNIQUE INDEX idx_isbn ON books(isbn);

When to Use Indexes

• Columns frequently used in WHERE clauses
• Columns used in JOIN conditions
• Columns used in ORDER BY

When NOT to Use Indexes

• Small tables
• Columns with many NULL values
• Columns that are frequently updated

Proper indexing can dramatically improve query performance!