hive新功能cube和rollup

1、cube简称数据魔方，可以实现hive多个任意维度的查询，cube(a,b,c)则首先会对(a,b,c)进行group by，然后依次是(a,b),(a,c),(a),(b,c),(b),(c),最后在对全表进行group by，他会统计所选列中值的所有组合的聚合

select device_id,os_id,app_id,client_version,from_id,count(user_id) from test_xinyan_reg group by device_id,os_id,app_id,client_version,from_id with cube;

此语句相当于group by后所有字段的排列组合，然后将结果union all起来

rollup可以实现从右到做递减多级的统计，显示统计某一层次结构的聚合。

相当于：

SELECT device_id,null,null,null,null ,count(user_id) FROM test_xinyan_reg group by device_id

UNION ALL

SELECT null,os_id,null,null,null ,count(user_id) FROM test_xinyan_reg group by os_id

UNION ALL

SELECT device_id,os_id,null,null,null ,count(user_id) FROM test_xinyan_reg group by device_id,os_id

UNION ALL

SELECT null,null,app_id,null,null ,count(user_id) FROM test_xinyan_reg group by app_id

UNION ALL

SELECT device_id,null,app_id,null,null ,count(user_id) FROM test_xinyan_reg group by device_id,app_id

UNION ALL

SELECT null,os_id,app_id,null,null ,count(user_id) FROM test_xinyan_reg group by os_id,app_id

UNION ALL

SELECT device_id,os_id,app_id,null,null ,count(user_id) FROM test_xinyan_reg group by device_id,os_id,app_id

UNION ALL

SELECT null,null,null,client_version,null ,count(user_id) FROM test_xinyan_reg group by client_version

UNION ALL

SELECT device_id,null,null,client_version,null ,count(user_id) FROM test_xinyan_reg group by device_id,client_version

UNION ALL

SELECT null,os_id,null,client_version,null ,count(user_id) FROM test_xinyan_reg group by os_id,client_version

UNION ALL

SELECT device_id,os_id,null,client_version,null ,count(user_id) FROM test_xinyan_reg group by device_id,os_id,client_version

UNION ALL

SELECT null,null,app_id,client_version,null ,count(user_id) FROM test_xinyan_reg group by app_id,client_version

UNION ALL

SELECT device_id,null,app_id,client_version,null ,count(user_id) FROM test_xinyan_reg group by device_id,app_id,client_version

UNION ALL

SELECT null,os_id,app_id,client_version,null ,count(user_id) FROM test_xinyan_reg group by os_id,app_id,client_version

UNION ALL

SELECT device_id,os_id,app_id,client_version,null ,count(user_id) FROM test_xinyan_reg group by device_id,os_id,app_id,client_version

UNION ALL

SELECT null,null,null,null,from_id ,count(user_id) FROM test_xinyan_reg group by from_id

UNION ALL

SELECT device_id,null,null,null,from_id ,count(user_id) FROM test_xinyan_reg group by device_id,from_id

UNION ALL

SELECT null,os_id,null,null,from_id ,count(user_id) FROM test_xinyan_reg group by os_id,from_id

UNION ALL

SELECT device_id,os_id,null,null,from_id ,count(user_id) FROM test_xinyan_reg group by device_id,os_id,from_id

UNION ALL

SELECT null,null,app_id,null,from_id ,count(user_id) FROM test_xinyan_reg group by app_id,from_id

UNION ALL

SELECT device_id,null,app_id,null,from_id ,count(user_id) FROM test_xinyan_reg group by device_id,app_id,from_id

UNION ALL

SELECT null,os_id,app_id,null,from_id ,count(user_id) FROM test_xinyan_reg group by os_id,app_id,from_id

UNION ALL

SELECT device_id,os_id,app_id,null,from_id ,count(user_id) FROM test_xinyan_reg group by device_id,os_id,app_id,from_id

UNION ALL

SELECT null,null,null,client_version,from_id ,count(user_id) FROM test_xinyan_reg group by client_version,from_id

UNION ALL

SELECT device_id,null,null,client_version,from_id ,count(user_id) FROM test_xinyan_reg group by device_id,client_version,from_id

UNION ALL

SELECT null,os_id,null,client_version,from_id ,count(user_id) FROM test_xinyan_reg group by os_id,client_version,from_id

UNION ALL

SELECT device_id,os_id,null,client_version,from_id ,count(user_id) FROM test_xinyan_reg group by device_id,os_id,client_version,from_id

UNION ALL

SELECT null,null,app_id,client_version,from_id ,count(user_id) FROM test_xinyan_reg group by app_id,client_version,from_id

UNION ALL

SELECT device_id,null,app_id,client_version,from_id ,count(user_id) FROM test_xinyan_reg group by device_id,app_id,client_version,from_id

UNION ALL

SELECT null,os_id,app_id,client_version,from_id ,count(user_id) FROM test_xinyan_reg group by os_id,app_id,client_version,from_id

UNION ALL

SELECT device_id,os_id,app_id,client_version,from_id ,count(user_id) FROM test_xinyan_reg group by device_id,os_id,app_id,client_version,from_id

UNION ALL

SELECT null,null,null,null,null ,count(user_id) FROM test_xinyan_reg

2、 rollup可以实现从右到左递减多级的统计，显示统计某一层次结构的聚合。

select device_id,os_id,app_id,client_version,from_id,count(user_id) from test_xinyan_reg group by device_id,os_id,app_id,client_version,from_id with rollup;

相当于

select device_id,os_id,app_id,client_version,from_id,count(user_id)

from test_xinyan_reg

group by device_id,os_id,app_id,client_version,from_id

grouping sets ((device_id,os_id,app_id,client_version,from_id),(device_id,os_id,app_id,client_version),(device_id,os_id,app_id),(device_id,os_id),(device_id),());