Hive分析窗口函数(一) SUM,AVG,MIN,MAX

Hive分析窗口函数(一) SUM,AVG,MIN,MAX

http://lxw1234.com/archives/2015/04/176.htm

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

  1. CREATE EXTERNAL TABLE lxw1234 (
  2. cookieid string,
  3. createtime string, --day
  4. pv INT
  5. ) ROW FORMAT DELIMITED
  6. FIELDS TERMINATED BY ','
  7. stored as textfile location '/tmp/lxw11/';
  8.  
  9. DESC lxw1234;
  10. cookieid STRING
  11. createtime STRING
  12. pv INT
  13.  
  14. hive> select * from lxw1234;
  15. OK
  16. cookie1 2015-04-10 1
  17. cookie1 2015-04-11 5
  18. cookie1 2015-04-12 7
  19. cookie1 2015-04-13 3
  20. cookie1 2015-04-14 2
  21. cookie1 2015-04-15 4
  22. cookie1 2015-04-16 4

SUM — 注意,结果和ORDER BY相关,默认为升序

  1. SELECT cookieid,
  2. createtime,
  3. pv,
  4. SUM(pv) OVER(PARTITION BY cookieid ORDER BY createtime) AS pv1, -- 默认为从起点到当前行
  5. 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
  6. SUM(pv) OVER(PARTITION BY cookieid) AS pv3, --分组内所有行
  7. 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
  8. 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
  9. 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
  10. FROM lxw1234;
  11.  
  12. cookieid createtime pv pv1 pv2 pv3 pv4 pv5 pv6
  13. -----------------------------------------------------------------------------
  14. cookie1 2015-04-10 1 1 1 26 1 6 26
  15. cookie1 2015-04-11 5 6 6 26 6 13 25
  16. cookie1 2015-04-12 7 13 13 26 13 16 20
  17. cookie1 2015-04-13 3 16 16 26 16 18 13
  18. cookie1 2015-04-14 2 18 18 26 17 21 10
  19. cookie1 2015-04-15 4 22 22 26 16 20 8
  20. 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。

  1. --AVG
  2. SELECT cookieid,
  3. createtime,
  4. pv,
  5. AVG(pv) OVER(PARTITION BY cookieid ORDER BY createtime) AS pv1, -- 默认为从起点到当前行
  6. 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
  7. AVG(pv) OVER(PARTITION BY cookieid) AS pv3, --分组内所有行
  8. 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
  9. 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
  10. 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
  11. FROM lxw1234;
  12. cookieid createtime pv pv1 pv2 pv3 pv4 pv5 pv6
  13. -----------------------------------------------------------------------------
  14. cookie1 2015-04-10 1 1.0 1.0 3.7142857142857144 1.0 3.0 3.7142857142857144
  15. cookie1 2015-04-11 5 3.0 3.0 3.7142857142857144 3.0 4.333333333333333 4.166666666666667
  16. cookie1 2015-04-12 7 4.333333333333333 4.333333333333333 3.7142857142857144 4.333333333333333 4.0 4.0
  17. cookie1 2015-04-13 3 4.0 4.0 3.7142857142857144 4.0 3.6 3.25
  18. cookie1 2015-04-14 2 3.6 3.6 3.7142857142857144 4.25 4.2 3.3333333333333335
  19. cookie1 2015-04-15 4 3.6666666666666665 3.6666666666666665 3.7142857142857144 4.0 4.0 4.0
  20. cookie1 2015-04-16 4 3.7142857142857144 3.7142857142857144 3.7142857142857144 3.25 3.25 4.0
  1. --MIN
  2. SELECT cookieid,
  3. createtime,
  4. pv,
  5. MIN(pv) OVER(PARTITION BY cookieid ORDER BY createtime) AS pv1, -- 默认为从起点到当前行
  6. 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
  7. MIN(pv) OVER(PARTITION BY cookieid) AS pv3, --分组内所有行
  8. 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
  9. 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
  10. 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
  11. FROM lxw1234;
  12.  
  13. cookieid createtime pv pv1 pv2 pv3 pv4 pv5 pv6
  14. -----------------------------------------------------------------------------
  15. cookie1 2015-04-10 1 1 1 1 1 1 1
  16. cookie1 2015-04-11 5 1 1 1 1 1 2
  17. cookie1 2015-04-12 7 1 1 1 1 1 2
  18. cookie1 2015-04-13 3 1 1 1 1 1 2
  19. cookie1 2015-04-14 2 1 1 1 2 2 2
  20. cookie1 2015-04-15 4 1 1 1 2 2 4
  21. cookie1 2015-04-16 4 1 1 1 2 2 4
  1. ----MAX
  2. SELECT cookieid,
  3. createtime,
  4. pv,
  5. MAX(pv) OVER(PARTITION BY cookieid ORDER BY createtime) AS pv1, -- 默认为从起点到当前行
  6. 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
  7. MAX(pv) OVER(PARTITION BY cookieid) AS pv3, --分组内所有行
  8. 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
  9. 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
  10. 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
  11. FROM lxw1234;
  12.  
  13. cookieid createtime pv pv1 pv2 pv3 pv4 pv5 pv6
  14. -----------------------------------------------------------------------------
  15. cookie1 2015-04-10 1 1 1 7 1 5 7
  16. cookie1 2015-04-11 5 5 5 7 5 7 7
  17. cookie1 2015-04-12 7 7 7 7 7 7 7
  18. cookie1 2015-04-13 3 7 7 7 7 7 4
  19. cookie1 2015-04-14 2 7 7 7 7 7 4
  20. cookie1 2015-04-15 4 7 7 7 7 7 4
  21. 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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posted on 2016-11-16 21:24  小西红柿  阅读(548)  评论(0)  编辑  收藏  举报

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