【Hive】总体标准差stddev()

最新推荐文章于 2025-06-21 08:15:31 发布

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最新推荐文章于 2025-06-21 08:15:31 发布 · 1.4w 阅读

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#hive

本文介绍了Hive中的聚合函数stddev()，用于计算样本总体的标准偏差。该函数支持作为窗口函数使用，对于数据分析和大数据处理具有重要意义。

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stddev()

计算基于给定的样本总体的标准偏差，为聚合函数，可使用窗口函数的表现方式。

-- 1.聚合函数
select col, stddev(num) as stddev_col
from (
    select 'A' as col, '1' as num
    union all
    select 'A' as col, '2' as num
    union all
    select 'A' as col, '3' as num
    union all
    select 'B' as col, '1' as num
    union all
    select 'B' as col, '2' as num
) as a
group by col

-- 2.窗口函数
select col, stddev(num) over(partition by col) as stddev_col
from (
    select 'A' as col, '1' as num
    union all
    select 'A' as col, '2' as num
    union all
    select 'A' as col, '3' as num
    union all
    select 'B' as col, '1' as num
    union all
    select 'B' as col, '2' as num
) as a