ALTER RESOURCE GROUP
The ALTER RESOURCE GROUP
statement is used to modify a resource group in a database.
Synopsis
AlterResourceGroupStmt:
"ALTER" "RESOURCE" "GROUP" IfExists ResourceGroupName ResourceGroupOptionList
IfExists ::=
('IF' 'EXISTS')?
ResourceGroupName:
Identifier
ResourceGroupOptionList:
DirectResourceGroupOption
| ResourceGroupOptionList DirectResourceGroupOption
| ResourceGroupOptionList ',' DirectResourceGroupOption
DirectResourceGroupOption:
"RU_PER_SEC" EqOpt stringLit
| "BURSTABLE"
TiDB supports the following DirectResourceGroupOption
, where Request Unit (RU) is a unified abstraction unit in TiDB for CPU, IO, and other system resources.
Option | Description | Example |
---|---|---|
RU_PER_SEC | Rate of RU backfilling per second | RU_PER_SEC = 500 indicates that this resource group is backfilled with 500 RUs per second |
If the BURSTABLE
attribute is set, TiDB allows the corresponding resource group to use the available system resources when the quota is exceeded.
Examples
Create a resource group named rg1
and modify its properties.
mysql> DROP RESOURCE GROUP IF EXISTS rg1;
Query OK, 0 rows affected (0.22 sec)
mysql> CREATE RESOURCE GROUP IF NOT EXISTS rg1
-> RU_PER_SEC = 100
-> BURSTABLE;
Query OK, 0 rows affected (0.08 sec)
mysql> SELECT * FROM information_schema.resource_groups WHERE NAME ='rg1';
+------+------------+-----------+
| NAME | RU_PER_SEC | BURSTABLE |
+------+------------+-----------+
| rg1 | 100 | YES |
+------+------------+-----------+
1 rows in set (1.30 sec)
mysql> ALTER RESOURCE GROUP rg1
-> RU_PER_SEC = 200;
Query OK, 0 rows affected (0.08 sec)
mysql> SELECT * FROM information_schema.resource_groups WHERE NAME ='rg1';
+------+------------+-----------+
| NAME | RU_PER_SEC | BURSTABLE |
+------+------------+-----------+
| rg1 | 200 | NO |
+------+------------+-----------+
1 rows in set (1.30 sec)
MySQL compatibility
MySQL also supports ALTER RESOURCE GROUP. However, the acceptable parameters are different from that of TiDB so that they are not compatible.