同一数据库中hive之双表join联合查询

hive (student)> show tables;
OK
course
student_test
Time taken: 0.056 seconds
hive (student)> select * from course;
OK
1	["English","Chinese","French","Japanese"]
2	["Chinese","French"]
3	["Chinese","French","Japanese"]
4	["Chinese","French","India"]
5	["Chinese","French","Green"]
Time taken: 0.38 seconds
hive (student)> select * from student_test;
OK
1	{"name":"KaiLee","age":24}
2	{"name":"DuoPing","age":24}
3	{"name":"JiangTao","age":25}
4	{"name":"LiuRiJi","age":23}
5	{"name":"GuangYuan","age":25}
Time taken: 0.111 seconds
hive (student)> describe student_test;
OK
id	int	the number of a student
basic_info	struct<name:string,age:int>	the basic information of a student
Time taken: 0.119 seconds
hive (student)> describe course;
OK
stu_num	string	the number of a student
choose_course	array<string>	the choosing course of a student
Time taken: 0.091 seconds
hive (student)> select s.basic_info.name,c.choose_course from student_test s join course c 
              > on s.id = c.stu_num;
Total MapReduce jobs = 1
Launching Job 1 out of 1
Number of reduce tasks not specified. Estimated from input data size: 1
In order to change the average load for a reducer (in bytes):
  set hive.exec.reducers.bytes.per.reducer=<number>
In order to limit the maximum number of reducers:
  set hive.exec.reducers.max=<number>
In order to set a constant number of reducers:
  set mapred.reduce.tasks=<number>
Starting Job = job_201303271617_0014, Tracking URL = http://localhost:50030/jobdetails.jsp?jobid=job_201303271617_0014
Kill Command = /home/landen/UntarFile/hadoop-1.0.4/libexec/../bin/hadoop job  -kill job_201303271617_0014
Hadoop job information for Stage-1: number of mappers: 2; number of reducers: 1
2013-03-29 22:13:21,374 Stage-1 map = 0%,  reduce = 0%
2013-03-29 22:14:27,913 Stage-1 map = 0%,  reduce = 0%
2013-03-29 22:14:46,595 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 3.64 sec
2013-03-29 22:14:47,597 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 3.64 sec
2013-03-29 22:14:48,600 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 3.64 sec
2013-03-29 22:14:49,603 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 3.64 sec
2013-03-29 22:14:50,607 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 3.64 sec
2013-03-29 22:14:51,610 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 3.64 sec
2013-03-29 22:14:52,613 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 3.64 sec
2013-03-29 22:14:53,615 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 3.64 sec
2013-03-29 22:14:54,618 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 3.64 sec
2013-03-29 22:14:55,625 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 3.64 sec
2013-03-29 22:14:56,629 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 3.64 sec
2013-03-29 22:14:57,633 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 3.64 sec
2013-03-29 22:14:58,635 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 3.64 sec
2013-03-29 22:14:59,638 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 3.64 sec
2013-03-29 22:15:00,642 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 3.64 sec
2013-03-29 22:15:01,645 Stage-1 map = 100%,  reduce = 33%, Cumulative CPU 3.64 sec
2013-03-29 22:15:02,648 Stage-1 map = 100%,  reduce = 33%, Cumulative CPU 3.64 sec
2013-03-29 22:15:03,657 Stage-1 map = 100%,  reduce = 33%, Cumulative CPU 3.64 sec
2013-03-29 22:15:04,663 Stage-1 map = 100%,  reduce = 100%, Cumulative CPU 6.14 sec
2013-03-29 22:15:05,679 Stage-1 map = 100%,  reduce = 100%, Cumulative CPU 6.14 sec
2013-03-29 22:15:06,686 Stage-1 map = 100%,  reduce = 100%, Cumulative CPU 6.14 sec
2013-03-29 22:15:07,690 Stage-1 map = 100%,  reduce = 100%, Cumulative CPU 6.14 sec
2013-03-29 22:15:08,698 Stage-1 map = 100%,  reduce = 100%, Cumulative CPU 6.14 sec
2013-03-29 22:15:09,702 Stage-1 map = 100%,  reduce = 100%, Cumulative CPU 6.14 sec
2013-03-29 22:15:10,706 Stage-1 map = 100%,  reduce = 100%, Cumulative CPU 6.14 sec
MapReduce Total cumulative CPU time: 6 seconds 140 msec
Ended Job = job_201303271617_0014
MapReduce Jobs Launched: 
Job 0: Map: 2  Reduce: 1   Cumulative CPU: 6.14 sec   HDFS Read: 720 HDFS Write: 155 SUCCESS
Total MapReduce CPU Time Spent: 6 seconds 140 msec
OK
KaiLee	["English","Chinese","French","Japanese"]
DuoPing	["Chinese","French"]
JiangTao	["Chinese","French","Japanese"]
LiuRiJi	["Chinese","French","India"]
GuangYuan	["Chinese","French","Green"]
Time taken: 119.14 seconds
原文地址:https://www.cnblogs.com/likai198981/p/2989740.html