📚 Database Optimization Tip #1

Ever wondered why your SELECT queries take forever on large tables?

Chances are, you’re missing proper indexing — one of the most effective ways to boost database performance. 💡

👉 What is an index?

Think of it like a book’s table of contents. Instead of flipping through every page (aka a full table scan), the database jumps straight to what you need.

📌 Real-world example:

Say you often run queries like:

SELECT * FROM users WHERE email = '[email protected]';

Adding an index like this helps:

CREATE INDEX idx_email ON users(email);

This simple step can significantly reduce lookup time.

⚠️ But be careful:

While indexes speed up reads, they can slow down writes (INSERTs, UPDATEs, DELETEs), since every index must also be updated.

Too many indexes = unnecessary overhead.

🔍 Best practices:

⭐ Index columns used in WHERE, JOIN, or ORDER BY clauses frequently.

⭐ Avoid indexing every column — be intentional.

⭐ Use tools (like PostgreSQL’s pg_stat_user_indexes or MySQL’s SHOW INDEX) to check for unused or redundant indexes.

⭐ Consider composite indexes when you often filter by multiple columns together.