Hive开窗

练习的时候发现hive也支持开窗函数

三个字段的意思：
用户名，月份，访问次数
 
A,2015-01,5
A,2015-01,15
B,2015-01,5
A,2015-01,8
B,2015-01,25
A,2015-01,5
A,2015-02,4
A,2015-02,6
B,2015-02,10
B,2015-02,5
A,2015-03,16
A,2015-03,22
B,2015-03,23
B,2015-03,10
B,2015-03,11
 

结果展示

用户	月份	截止当月最大访问次数	截止当月累计访问次数	当月访问次数
A	Jan-15	33	33	33
A	Feb-15	33	43	10
A	Mar-15	38	81	38
B	Jan-15	30	30	30
B	Feb-15	30	45	15
B	Mar-15	44	89	44
B	Mar-15	44	89	44

用这个题正好验证了开窗的使用方法与Oracle一样，这就很爽了！！！

select t.name,t.d,t.times as thismonth,
sum(t.times)over(partition by t.name order by t.d rows between  unbounded preceding and  current row ) sums,
max(t.times)over(partition by t.name order by t.d rows between unbounded preceding and current row) max 
from(select t.name,t.t_date d,sum(t.times) times From t_hive01 t group by t.name,t.t_date)t;