Note
- This variable is available starting with OceanBase Database V4.3.2 in the V4.3.x series.
- This variable is available starting with OceanBase Database V4.2.3 in the V4.2.x series.
Description
ob_compatibility_control specifies the compatibility mode when there is a compatibility conflict between MySQL 5.7 and MySQL 8.0. If you set ob_compatibility_control to MYSQL5.7, you can still use MySQL 8.0 features that do not have compatibility conflicts. You can specify the compatibility mode when you create a tenant. After the tenant is created, you cannot modify the compatibility mode.
Applicability
This variable applies only to the MySQL-compatible mode of OceanBase Database.
Privilege requirements
Query variables
The
systenant and all user tenants can execute theSHOW VARIABLESstatement or query theinformation_schema.GLOBAL_VARIABLESview (MySQL-compatible mode) to view the values of global system variables.Modify variables
After a tenant is created, you cannot modify this variable by executing an SQL statement.
Attributes
Attribute |
Description |
|---|---|
| Parameter type | Enum |
| Default value | MYSQL5.7 |
| Value range | ["MYSQL5.7","MYSQL8.0"] |
| Scope | Global |
| Modifiable | No. You can specify this variable only when you create a tenant. After the tenant is created, you cannot modify the value by executing the SET or ALTER SESSION SET statement. |
| Read-only | Yes |
Usage notes
When you upgrade a tenant that does not have this variable to a version that has this variable, the variable takes the default value
MYSQL5.7. When you create a new tenant, you can specify the compatibility mode.For features that are implemented in MySQL 8.0 in earlier versions, if
ob_compatibility_version < 4.2.3, the features are compatible with MySQL 8.0 regardless of the value ofob_compatibility_control.
Examples
Specify the compatibility mode as MySQL 5.7 when you create a tenant.
obclient> create tenant tenant_m57 zone_list=('z1'),primary_zone='z1',resource_pool_list=('pool1') set ob_compatibility_mode='mysql',ob_compatibility_control='MYSQL5.7',ob_tcp_invited_nodes='%';