Alex的Hadoop菜鸟教程:第10课Hive入门教程 - 数据库编程

elds TERMINATED BY '\054';
查入一些数据

# cat 2014-09-09-CN 
1,tammy
2,eric
# cat 2014-09-10-CN 
3,paul
4,jolly
# cat 2014-09-10-EN 
44,ivan
66,billy

导入hive

hive> LOAD DATA LOCAL INPATH '/home/alex/2014-09-09-CN' INTO TABLE p_student partition(daytime='2014-09-09',country='CN');
Copying data from file:/home/alex/2014-09-09-CN
Copying file: file:/home/alex/2014-09-09-CN
Loading data to table default.p_student partition (daytime=2014-09-09, country=CN)
Partition default.p_student{daytime=2014-09-09, country=CN} stats: [num_files: 1, num_rows: 0, total_size: 19, raw_data_size: 0]
Table default.p_student stats: [num_partitions: 1, num_files: 1, num_rows: 0, total_size: 19, raw_data_size: 0]
OK
Time taken: 0.736 seconds
hive> LOAD DATA LOCAL INPATH '/home/alex/2014-09-10-CN' INTO TABLE p_student partition(daytime='2014-09-10',country='CN');
Copying data from file:/home/alex/2014-09-10-CN
Copying file: file:/home/alex/2014-09-10-CN
Loading data to table default.p_student partition (daytime=2014-09-10, country=CN)
Partition default.p_student{daytime=2014-09-10, country=CN} stats: [num_files: 1, num_rows: 0, total_size: 19, raw_data_size: 0]
Table default.p_student stats: [num_partitions: 2, num_files: 2, num_rows: 0, total_size: 38, raw_data_size: 0]
OK
Time taken: 0.691 seconds
hive> LOAD DATA LOCAL INPATH '/home/alex/2014-09-10-EN' INTO TABLE p_student partition(daytime='2014-09-10',country='EN');
Copying data from file:/home/alex/2014-09-10-EN
Copying file: file:/home/alex/2014-09-10-EN
Loading data to table default.p_student partition (daytime=2014-09-10, country=EN)
Partition default.p_student{daytime=2014-09-10, country=EN} stats: [num_files: 1, num_rows: 0, total_size: 21, raw_data_size: 0]
Table default.p_student stats: [num_partitions: 3, num_files: 3, num_rows: 0, total_size: 59, raw_data_size: 0]
OK
Time taken: 0.622 seconds

看看存储结构

# hdfs dfs -ls /user/hive/warehouse/p_student
Found 2 items
drwxr-xr-x   - root supergroup          0 2014-12-08 16:10 /user/hive/warehouse/p_student/daytime=2014-09-09
drwxr-xr-x   - root supergroup          0 2014-12-08 16:10 /user/hive/warehouse/p_student/daytime=2014-09-10
# hdfs dfs -ls /user/hive/warehouse/p_student/daytime=2014-09-09
Found 1 items
drwxr-xr-x   - root supergroup          0 2014-12-08 16:10 /user/hive/warehouse/p_student/daytime=2014-09-09/country=CN

查询一下数据

hive> select * from p_student;
OK
1	tammy	2014-09-09	CN
2	eric	2014-09-09	CN
3	paul	2014-09-10	CN
4	jolly	2014-09-10	CN
44	ivan	2014-09-10	EN
66	billy	2014-09-10	EN
Time taken: 0.228 seconds, Fetched: 6 row(s)

hive> select * from p_student where daytime='2014-09-10' and country='EN';
OK
44	ivan	2014-09-10	EN
66	billy	2014-09-10	EN
Time taken: 0.224 seconds, Fetched: 2 row(s)

桶表

桶表是根据某个字段的hash值，来将数据扔到不同的“桶”里面。外国人有个习惯，就是分类东西的时候摆几个桶，上面贴不同的标签，所以他们取名的时候把这种表形象的取名为桶表。桶表表专门用于采样分析
下面这个例子是官网教程直接拷贝下来的，因为分区表跟桶表是可以同时使用的，所以这个例子中同时使用了分区跟桶两种特性

CREATE TABLE b_student(id INT, name STRING)
PARTITIONED BY(dt STRING, country STRING)
CLUSTERED BY(id) SORTED BY(name) INTO 4 BUCKETS
row format delimited 
    fields TERMINATED BY '\054';

意思是根据userid来进行计算hash值，用viewTIme来排序存储做数据跟导入的过程我就不在赘述了，这是导入后的数据

hive> select * from b_student;
OK
1	tammy	2014-09-09	CN
2	eric	2014-09-09	CN
3	paul	2014-09-10	CN
4	jolly	2014-09-10	CN
34	allen	2014-09-11

Alex的Hadoop菜鸟教程:第10课Hive入门教程(三)

桶表