JOIN Optimization Tips
Make your JOIN queries faster.
Tip 1: Index Join Columns
CREATE INDEX idx_customer_id ON orders(customer_id);
SELECT * FROM customers
JOIN orders ON customers.id = orders.customer_id;Index makes JOIN much faster!
Tip 2: Filter Before Joining
-- Better: Filter first
SELECT * FROM customers
JOIN orders ON customers.id = orders.customer_id
WHERE orders.status = 'completed';Tip 3: Use INNER JOIN When Possible
INNER JOIN is faster than LEFT JOIN (when you do not need unmatched rows).
Summary
- Index join columns
- Filter early with WHERE
- Use INNER JOIN when possible