HIVE的内部表和外部表

Hive的数据表

创建数据文件 inner_table.dat
创建表 hive>create table inner_table (key string);
加载数据 hive>load data local inpath ‘/root/inner_table.dat’ into table inner_table;
查看数据 hive> select * from inner_table;
hive> select count(*) from inner_table ;
删除表 hive>drop table inner_table;

内部表和外表表的区别

Hive的分区

添加分区

ALTER TABLE table_name ADD PARTITION (partCol = ‘value1’) location>’loc1’; //示例

ALTER TABLE table_name ADD IF NOT EXISTS PARTITION (dt=’20130101’)> LOCATION ‘/user/hadoop/warehouse/table_name/dt=20130101’; //一次添加一个分区

ALTER TABLE page_view ADD PARTITION (dt=’2008-08-08’, country=’us’) location ‘/path/to/us/part080808’ PARTITION (dt=’2008-08-09’, country=’us’) location ‘/path/to/us/part080809’; //一次添加多个分区

删除分区

ALTER TABLE login DROP IF EXISTS PARTITION (dt=’2008-08-08’);

ALTER TABLE page_view DROP IF EXISTS PARTITION (dt=’2008-08-08’, country=’us’);

修改分区

ALTER TABLE table_name PARTITION (dt=’2008-08-08’) SET LOCATION “new
location”;

ALTER TABLE table_name PARTITION (dt=’2008-08-08’) RENAME TO PARTITION
(dt=’20080808’);

添加列

ALTER TABLE table_name ADD COLUMNS (col_name STRING);
//在所有存在的列后面，但是在分区列之前添加一列

修改列

CREATE TABLE test_change (a int, b int, c int);

// will change column a’s name to a1

ALTER TABLE test_change CHANGE a a1 INT;

// will change column a’s name to a1, a’s data type to string, and put it after 、column b. The new table’s structure is: b int, a1 string, c int

ALTER TABLE test_change CHANGE a a1 STRING AFTER b;

// will change column b’s name to b1, and put it as the first column. The new table’s structure is: b1 int, a string, c int

ALTER TABLE test_change CHANGE b b1 INT FIRST;

修改表属性

alter table table_name set TBLPROPERTIES (‘EXTERNAL’=’TRUE’); //内部表转外部表
alter table table_name set TBLPROPERTIES (‘EXTERNAL’=’FALSE’); //外部表转内部表

表的重命名

ALTER TABLE table_name RENAME TO new_table_name