Optimization: LEFT JOIN Filter Placement

Interviewer prompt: Choose correct and performant query to keep all users and count only failed logins. Query A: SELECT u.user_id, COUNT(l.user_id) FROM users u LEFT JOIN logins l ON u.user_id = l.user_id WHERE l.status = 'FAILED' GROUP BY u.user_id; Query B: SELECT u.user_id, COUNT(l.user_id) FROM users u LEFT JOIN logins l ON u.user_id = l.user_id AND l.status = 'FAILED' GROUP BY u.user_id;