Hive中提供了越来越多的分析函数，用于完成负责的统计分析。抽时间将所有的分析窗口函数理一遍，将陆续发布。
今天先看几个基础的，SUM、AVG、MIN、MAX。
用于实现分组内所有和连续累积的统计。
Hive版本为 apache-hive-0.13.1
数据准备
CREATE EXTERNAL TABLE lxw1234 ( cookieid string, createtime string, --day pv INT ) ROW FORMAT DELIMITED FIELDS TERMINATED BY ',' stored as textfile location '/tmp/lxw11/'; DESC lxw1234; cookieid STRING createtime STRING pv INT hive> select * from lxw1234; OK cookie1 2015-04-10 1 cookie1 2015-04-11 5 cookie1 2015-04-12 7 cookie1 2015-04-13 3 cookie1 2015-04-14 2 cookie1 2015-04-15 4 cookie1 2015-04-16 4
SUM — 注意,结果和ORDER BY相关,默认为升序
SELECT cookieid, createtime, pv, SUM(pv) OVER(PARTITION BY cookieid ORDER BY createtime) AS pv1, -- 默认为从起点到当前行 SUM(pv) OVER(PARTITION BY cookieid ORDER BY createtime ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS pv2, --从起点到当前行，结果同pv1 SUM(pv) OVER(PARTITION BY cookieid) AS pv3, --分组内所有行 SUM(pv) OVER(PARTITION BY cookieid ORDER BY createtime ROWS BETWEEN 3 PRECEDING AND CURRENT ROW) AS pv4, --当前行+往前3行 SUM(pv) OVER(PARTITION BY cookieid ORDER BY createtime ROWS BETWEEN 3 PRECEDING AND 1 FOLLOWING) AS pv5, --当前行+往前3行+往后1行 SUM(pv) OVER(PARTITION BY cookieid ORDER BY createtime ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING) AS pv6 ---当前行+往后所有行 FROM lxw1234; cookieid createtime pv pv1 pv2 pv3 pv4 pv5 pv6 ----------------------------------------------------------------------------- cookie1 2015-04-10 1 1 1 26 1 6 26 cookie1 2015-04-11 5 6 6 26 6 13 25 cookie1 2015-04-12 7 13 13 26 13 16 20 cookie1 2015-04-13 3 16 16 26 16 18 13 cookie1 2015-04-14 2 18 18 26 17 21 10 cookie1 2015-04-15 4 22 22 26 16 20 8 cookie1 2015-04-16 4 26 26 26 13 13 4
pv1: 分组内从起点到当前行的pv累积，如，11号的pv1=10号的pv+11号的pv, 12号=10号+11号+12号
pv2: 同pv1
pv3: 分组内(cookie1)所有的pv累加
pv4: 分组内当前行+往前3行，如，11号=10号+11号， 12号=10号+11号+12号， 13号=10号+11号+12号+13号， 14号=11号+12号+13号+14号
pv5: 分组内当前行+往前3行+往后1行，如，14号=11号+12号+13号+14号+15号=5+7+3+2+4=21
pv6: 分组内当前行+往后所有行，如，13号=13号+14号+15号+16号=3+2+4+4=13，14号=14号+15号+16号=2+4+4=10
如果不指定ROWS BETWEEN,默认为从起点到当前行;
如果不指定ORDER BY，则将分组内所有值累加;
关键是理解ROWS BETWEEN含义,也叫做WINDOW子句：
PRECEDING：往前
FOLLOWING：往后
CURRENT ROW：当前行
UNBOUNDED：起点，UNBOUNDED PRECEDING 表示从前面的起点， UNBOUNDED FOLLOWING：表示到后面的终点
–其他AVG，MIN，MAX，和SUM用法一样。
--AVG SELECT cookieid, createtime, pv, AVG(pv) OVER(PARTITION BY cookieid ORDER BY createtime) AS pv1, -- 默认为从起点到当前行 AVG(pv) OVER(PARTITION BY cookieid ORDER BY createtime ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS pv2, --从起点到当前行，结果同pv1 AVG(pv) OVER(PARTITION BY cookieid) AS pv3, --分组内所有行 AVG(pv) OVER(PARTITION BY cookieid ORDER BY createtime ROWS BETWEEN 3 PRECEDING AND CURRENT ROW) AS pv4, --当前行+往前3行 AVG(pv) OVER(PARTITION BY cookieid ORDER BY createtime ROWS BETWEEN 3 PRECEDING AND 1 FOLLOWING) AS pv5, --当前行+往前3行+往后1行 AVG(pv) OVER(PARTITION BY cookieid ORDER BY createtime ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING) AS pv6 ---当前行+往后所有行 FROM lxw1234; cookieid createtime pv pv1 pv2 pv3 pv4 pv5 pv6 ----------------------------------------------------------------------------- cookie1 2015-04-10 1 1.0 1.0 3.7142857142857144 1.0 3.0 3.7142857142857144 cookie1 2015-04-11 5 3.0 3.0 3.7142857142857144 3.0 4.333333333333333 4.166666666666667 cookie1 2015-04-12 7 4.333333333333333 4.333333333333333 3.7142857142857144 4.333333333333333 4.0 4.0 cookie1 2015-04-13 3 4.0 4.0 3.7142857142857144 4.0 3.6 3.25 cookie1 2015-04-14 2 3.6 3.6 3.7142857142857144 4.25 4.2 3.3333333333333335 cookie1 2015-04-15 4 3.6666666666666665 3.6666666666666665 3.7142857142857144 4.0 4.0 4.0 cookie1 2015-04-16 4 3.7142857142857144 3.7142857142857144 3.7142857142857144 3.25 3.25 4.0
--MIN SELECT cookieid, createtime, pv, MIN(pv) OVER(PARTITION BY cookieid ORDER BY createtime) AS pv1, -- 默认为从起点到当前行 MIN(pv) OVER(PARTITION BY cookieid ORDER BY createtime ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS pv2, --从起点到当前行，结果同pv1 MIN(pv) OVER(PARTITION BY cookieid) AS pv3, --分组内所有行 MIN(pv) OVER(PARTITION BY cookieid ORDER BY createtime ROWS BETWEEN 3 PRECEDING AND CURRENT ROW) AS pv4, --当前行+往前3行 MIN(pv) OVER(PARTITION BY cookieid ORDER BY createtime ROWS BETWEEN 3 PRECEDING AND 1 FOLLOWING) AS pv5, --当前行+往前3行+往后1行 MIN(pv) OVER(PARTITION BY cookieid ORDER BY createtime ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING) AS pv6 ---当前行+往后所有行 FROM lxw1234; cookieid createtime pv pv1 pv2 pv3 pv4 pv5 pv6 ----------------------------------------------------------------------------- cookie1 2015-04-10 1 1 1 1 1 1 1 cookie1 2015-04-11 5 1 1 1 1 1 2 cookie1 2015-04-12 7 1 1 1 1 1 2 cookie1 2015-04-13 3 1 1 1 1 1 2 cookie1 2015-04-14 2 1 1 1 2 2 2 cookie1 2015-04-15 4 1 1 1 2 2 4 cookie1 2015-04-16 4 1 1 1 2 2 4
----MAX SELECT cookieid, createtime, pv, MAX(pv) OVER(PARTITION BY cookieid ORDER BY createtime) AS pv1, -- 默认为从起点到当前行 MAX(pv) OVER(PARTITION BY cookieid ORDER BY createtime ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS pv2, --从起点到当前行，结果同pv1 MAX(pv) OVER(PARTITION BY cookieid) AS pv3, --分组内所有行 MAX(pv) OVER(PARTITION BY cookieid ORDER BY createtime ROWS BETWEEN 3 PRECEDING AND CURRENT ROW) AS pv4, --当前行+往前3行 MAX(pv) OVER(PARTITION BY cookieid ORDER BY createtime ROWS BETWEEN 3 PRECEDING AND 1 FOLLOWING) AS pv5, --当前行+往前3行+往后1行 MAX(pv) OVER(PARTITION BY cookieid ORDER BY createtime ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING) AS pv6 ---当前行+往后所有行 FROM lxw1234; cookieid createtime pv pv1 pv2 pv3 pv4 pv5 pv6 ----------------------------------------------------------------------------- cookie1 2015-04-10 1 1 1 7 1 5 7 cookie1 2015-04-11 5 5 5 7 5 7 7 cookie1 2015-04-12 7 7 7 7 7 7 7 cookie1 2015-04-13 3 7 7 7 7 7 4 cookie1 2015-04-14 2 7 7 7 7 7 4 cookie1 2015-04-15 4 7 7 7 7 7 4 cookie1 2015-04-16 4 7 7 7 4 4 4
其他函数的介绍将陆续整理发布。。
点此查看所有Hive窗口分析函数的文章
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