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ALTER TABLEGROUP

描述

该语句用来执行以下操作:

  • 对一个表组增加多张表。

  • 修改表组的分区规则。

  • 修改表组的 Locality 和 Primary Zone。

格式

  • 对一个表组增加多张表。

ALTER TABLEGROUP tablegroupname ADD [TABLE] tblname [, tblname…]
  • 修改表组的分区规则。

ALTER TABLEGROUP tablegroupname alter_tg_partition_option
alter_tg_partition_option:
DROP PARTITION '(' name_list ')'
| ADD PARTITION opt_range_partition_list
| modify_tg_partition_info
  • 修改表组的 Locality 和 Primary Zone。

ALTER TABLEGROUP tablegroupname alter_tablegroup_actions
alter_tablegroup_actions:
alter_tablegroup_action
| alter_tablegroup_action, alter_tablegroup_action
alter_tablegroup_action:
SET LOCALITY [=] locality_name
|SET PRIMARY_ZONE [=] primary_zone_name

参数解释

参数

描述

tablegroupname

指定表组。

tblname

表名。对一个表组增加多张表时,表与表之间以逗号(‘,’)分隔。

当添加多个表时,允许表名重复。如果待添加的表已经属于tablegroupname的表格组,系统不报错。

modify_tg_partition_info

修改表组的分区规则。

LOCALITY locality_name

指定表组的 Locality。

PRIMARY_ZONE primary_zone_name

指定表组的主 Zone。

示例

  • 创建表组tgh,并将表组的 Locality修改为 F@z1,并创建两张关系表ttgh1ttgh2

obclient>CREATE TABLEGROUP tgh LOCALITY='F,R{ALL_SERVER}@z1' PARTITION BY HASH PARTITIONS 10;
Query OK, 0 rows affected (0.09 sec)

obclient>SELECT LOCALITY FROM sys.all_virtual_tablegroup_agent WHERE tablegroup_name ='TGH';
+------------------------------------+
| LOCALITY                           |
+------------------------------------+
| FULL{1},READONLY{ALL_SERVER}@1 |
+------------------------------------+
1 row in set (0.01 sec)

obclient>ALTER TABLEGROUP tgh SET LOCALITY ='F@z1';
Query OK, 0 rows affected (0.09 sec)

obclient>SELECT LOCALITY FROM sys.all_virtual_tablegroup_agent WHERE tablegroup_name ='TGH';
+------------+
| LOCALITY  |
+------------+
| FULL{1}@z1 |
+------------+
1 row in set (0.05 sec)

obclient>SELECT LOCALITY FROM  sys.all_virtual_tablegroup_agent WHERE tablegroup_id=(SELECT tablegroup_id FROM sys.all_virtual_tablegroup_agent WHERE tablegroup_name ='TGH');
+---------------+
| LOCALITY      |
+---------------+
| FULL{1}@z1 |
+---------------+
1 row in set (0.00 sec)

obclient>CREATE TABLE ttgh1(c1 INT, c2 INT) TABLEGROUP = tgh LOCALITY='F@z1' PARTITION BY HASH(c1) PARTITIONS 10;
Query OK, 0 rows affected (0.55 sec)

obclient>CREATE TABLE ttgh2(c1 INT, c2 INT) TABLEGROUP = tgh LOCALITY='F@z1' PARTITION BY HASH(c1) PARTITIONS 10;
Query OK, 0 rows affected (0.39 sec)