小编nag*_*dev的帖子

我有一个需要分页的表（没有关系）。为此，我使用 Doctrine 分页工具。

该表包含 634484 条记录。Doctrine 执行以下查询：

SELECT p0_.id AS id_0, p0_.name AS name_1, p0_.level AS level_2, p0_.alignment AS alignment_3, p0_.account_id AS account_id_4 FROM player.player p0_ ORDER BY p0_.level DESC LIMIT 25;

解释：

id  select_type table   partitions  type    possible_keys   key key_len ref rows    filtered    Extra
1   SIMPLE  p0_     index       search  1       25  100.00

执行时间：1.04 ms

有问题的查询：

SELECT 
  COUNT(*) AS dctrn_count 
FROM 
  (
    SELECT 
      DISTINCT id_0 
    FROM 
      (
        SELECT 
          p0_.id AS id_0, 
          p0_.name AS name_1, 
          p0_.level AS level_2, 
          p0_.alignment AS …