Hive多维分析函数——With cube、Grouping sets、With rollup

有些指标涉及【多维度】的聚合，大的汇总维度，小的明细维度，需要精细化的下钻。

grouping sets： 多维度组合，组合维度自定义；
with cube： 多维度组合，程序自由组合，组合为各个维度的笛卡尔积；
with rollup：是 with cube的子集，以左侧维度为主，即不允许左侧为NULL，右侧为非NULL的情况出现

一、grouping sets

0 数据准备

with test1 as(select '2021-08' as month_date,'2021-08-11' as day_date,10 as pvunion allselect '2021-08' as month_date,'2021-08-10' as day_date,15 as pvunion allselect '2021-08' as month_date,'2021-08-08' as day_date,35 as pvunion allselect '2021-07' as month_date,'2021-07-08' as day_date,35 as pvunion allselect '2021-07' as month_date,'2021-07-06' as day_date,25 as pvunion allselect '2021-07' as month_date,'2021-07-03' as day_date,15 as pv)select month_date,day_date,sum(pv) as pvfrom test1group by month_date,day_dategrouping sets((),(month_date),(month_date,day_date),(day_date))order by month_date,day_date;

1 结果分析

二、with cube

0 数据准备

with test1 as
(select '2021-08' as month_date,'2021-08-11' as day_date,10 as pvunion allselect '2021-08' as month_date,'2021-08-10' as day_date,15 as pvunion allselect '2021-08' as month_date,'2021-08-08' as day_date,35 as pvunion allselect '2021-07' as month_date,'2021-07-08' as day_date,35 as pvunion allselect '2021-07' as month_date,'2021-07-06' as day_date,25 as pvunion allselect '2021-07' as month_date,'2021-07-03' as day_date,15 as pv)select month_date,day_date,sum(pv) as pvfrom test1group by month_date,day_datewith cubeorder by month_date,day_date;

1 结果分析

2 总结

从with cube和grouping sets的案例可以看出，两个结果是一样的；
with cube的维度组合（各个维度的笛卡尔积）就是groupingsets里面手动添加的维度，即为month_date,day_date两个维度的笛卡尔积。维度组合即为：()、 (month_date)、 (month_date,day_date)、 (day_date)

三、 with rollup

0 数据准备

with test1 as
(select '2021-08' as month_date,'2021-08-11' as day_date,10 as pvunion allselect '2021-08' as month_date,'2021-08-10' as day_date,15 as pvunion allselect '2021-08' as month_date,'2021-08-08' as day_date,35 as pvunion allselect '2021-07' as month_date,'2021-07-08' as day_date,35 as pvunion allselect '2021-07' as month_date,'2021-07-06' as day_date,25 as pvunion allselect '2021-07' as month_date,'2021-07-03' as day_date,15 as pv)select month_date,day_date,sum(pv) as pv
from test1
group by month_date,day_date
with rollup
order by month_date,day_date;