MySQL questions

In MySQL, JOIN operations are used to combine rows from two or more tables based on related columns. Use `INNER JOIN` to return records with matching values in both tables, `LEFT JOIN` to return all records from the left table and matched records from the right table, and `RIGHT JOIN` for the opposite. For example, `SELECT * FROM orders INNER JOIN customers ON orders.customer_id = customers.id` retrieves orders with customer details.

MyISAM is a non-transactional storage engine, ideal for read-heavy applications, while InnoDB supports transactions, foreign keys, and row-level locking, making it suitable for high-concurrency environments. For instance, InnoDB is preferable for e-commerce sites where data integrity is critical.