Hive用户可以通过alter语句更改table属性 Alter Partitions增加partitions： ALTER TABLE table_name ADD [IF NOT EXISTS]
hive用户可以通过alter语句更改table属性
Alter Partitions
增加partitions：
ALTER TABLE table_name
ADD [IF NOT EXISTS]
PARTITION partition_spec [LOCATION ‘location1’]
partition_spec [LOCATION ‘location2’] …
partition_spec:
(partition_col = partition_col_value, partition_col = partiton_col_value, …)
删除partitions：
ALTER TABLE table_name DROP [IF EXISTS] partition_spec, partition_spec,…
可自行修改点亮模式的星级评分
可自行修改点亮模式的星级评分
23 查看详情 
示例：
hive> create table alter_test(id INT, name STRING)
> partitioned by(dt STRING)
> row format delimited fields terminated by ‘,’;
OK
Time taken: 0.259 seconds
hive> create table alter_tmp(id INT, name STRING，dt STRING)
> row format delimited fields terminated by ‘,’;
OK
Time taken: 2.078 seconds
hive> load data local inpath ‘/home/work/data/alter_test.txt’ into table alter_tmp;
Copying data from file:/home/work/data/alter_test.txt
Copying file: file:/home/work/data/alter_test.txt
Loading data to table default.alter_tmp
OK
Time taken: 2.71 seconds
hive> set hive.exec.dynamic.partition.mode=nonstrict;
hive> set hive.exec.dynamic.partition=true;
hive> insert overwrite table alter_test partition(dt)
> select id,name,dt
> from alter_tmp;
OK
Time taken: 25.988 seconds
$ cat alter_test2.txt
1,zxm,2012-08-13
2,ljz,2012-08-13
$ Hadoop fs -put alter_test2.txt /data/
hive> alter table alter_test add partition(dt=’2012-08-13′) location ‘/data’;
OK
Time taken: 8.717 seconds
$ hadoop fs -ls /user/hive/warehouse/alter_test/
Found 3 items
drwxr-xr-x – work supergroup 0 2012-08-12 20:50 /user/hive/warehouse/alter_test/dt=2012-08-10
drwxr-xr-x – work supergroup 0 2012-08-12 20:50 /user/hive/warehouse/alter_test/dt=2012-08-11
drwxr-xr-x – work supergroup 0 2012-08-12 20:50 /user/hive/warehouse/alter_test/dt=2012-08-12
hive> select * from alter_test where dt=’2012-08-13′;
OK
1 zxm 2012-08-13
2 ljz 2012-08-13
Time taken: 6.064 seconds
$ hadoop fs -rmr /data
hive> select * from alter_test where dt=’2012-08-13′;
OK
Time taken: 1.903 seconds
hive> show partitions alter_test;
OK
dt=2012-08-10
dt=2012-08-11
dt=2012-08-12
dt=2012-08-13
Time taken: 0.546 seconds
> alter table alter_test add partition(dt=’2012-08-14′) partition(dt=’2012-08-15′);
OK
Time taken: 0.57 seconds
hive> alter table alter_test drop partition(dt=’2012-08-10′);
Dropping the partition dt=2012-08-10
OK
Time taken: 4.509 seconds
$ hadoop fs -ls /user/hive/warehouse/alter_test/
Found 4 items
drwxr-xr-x – work supergroup 0 2012-08-12 20:50 /user/hive/warehouse/alter_test/dt=2012-08-11
drwxr-xr-x – work supergroup 0 2012-08-12 20:50 /user/hive/warehouse/alter_test/dt=2012-08-12
drwxr-xr-x – work supergroup 0 2012-08-13 02:15 /user/hive/warehouse/alter_test/dt=2012-08-14
drwxr-xr-x – work supergroup 0 2012-08-13 02:15 /user/hive/warehouse/alter_test/dt=2012-08-15
注意：
1. hive可以同时增加或者删除多个partition
2. 使用location关键字时，，增加的partition以类似extend table数据的形式存在外部。
版权声明：本文内容由互联网用户自发贡献，该文观点仅代表作者本人。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。
如发现本站有涉嫌抄袭侵权/违法违规的内容， 请发送邮件至 chuangxiangniao@163.com 举报，一经查实，本站将立刻删除。
发布者：程序猿，转转请注明出处：https://www.chuangxiangniao.com/p/1084170.html
微信扫一扫 
支付宝扫一扫 
