前三分位、中三分位和后三分位
将数据按三分位或四分位拆分，常用于了解数据集中的数值分布。对前三分位、中三分位和后三分位分别计算汇总统计量（平均值、总和、标准差等），有助于判断数值大致服从什么分布。
本练习是课程的一部分
PostgreSQL 汇总统计与窗口函数
交互式实操练习
通过完成这段示例代码来试试这个练习。
WITH Athlete_Medals AS (
SELECT Athlete, COUNT(*) AS Medals
FROM Summer_Medals
GROUP BY Athlete
HAVING COUNT(*) > 1)
SELECT
Athlete,
Medals,
-- Split athletes into thirds by their earned medals
___ ___ ___ AS Third
FROM Athlete_Medals
ORDER BY Medals DESC, Athlete ASC;