mysql 찾을 최대 값을 행
SELECT t1.*
FROM employees t1
INNER JOIN (
SELECT id, max(salary) AS salary FROM employees GROUP BY id
) t2 ON t1.id = t2.id AND t1.salary = t2.salary;
mysql 테이블에 최대 수
4 billion tables
https://dev.mysql.com/doc/refman/8.0/en/database-count-limit.html