mysql随机获取10调数据（千万级，查询速度最快）

SELECT * FROM article AS t1 JOIN
   (SELECT
          ROUND(
              RAND() * (
                  (SELECT MAX(id) FROM article) - (SELECT MIN(id) FROM article)) +
                  (SELECT MIN(id) FROM article)
             ) AS id
      ) AS t2
WHERE t1.id >= t2.id ORDER BY t1.id LIMIT 10;