Note
This variable was introduced in OceanBase Database V4.0.0.
Description
log_row_value_options specifies whether LOB fields use partial updates.
Applicability
This variable is applicable to only OceanBase Database in MySQL mode.
Limitations
Query the variable
Global-level operation
In the
systenant or a user tenant, you can execute theSHOW VARIABLESstatement to query the variable at the global level or query theinformation_schema.GLOBAL_VARIABLESview (in MySQL mode) for the variable at the global level.Session-level operation
In the
systenant or a user tenant, you can execute theSHOW VARIABLESstatement to query the variable at the session level or query theinformation_schema.SESSION_VARIABLESview (in MySQL mode) for the variable at the session level.
Modify the variable
Global-level operation
In the
systenant, you can directly change the value of the variable at the global level.In a MySQL user tenant, you must have the
SUPERorALTER SYSTEMprivilege to change the value of the variable at the global level.
Session-level operation
In the
systenant or a user tenant, you can directly change the value of the variable at the session level for the current tenant.
Attributes
Attribute |
Description |
|---|---|
| Type | Varchar |
| Default value | Empty string |
| Value range | '' and partial_json
|
| Effective scope |
|
| Modifiable | Yes. You can use the SET statement to modify the variable. |
Considerations
The value partial_json specifies to enable partial updates for JSON documents. When you update JSON data by using the json_set/json_remove/json_replace expression, partial updates, instead of incremental updates, are performed. This can improve the performance of updating large-sized JSON data.
Examples
Enable partial updates for JSON documents.
Session-level operation
obclient> SET log_row_value_options="partial_json";Global-level operation
obclient> SET GLOBAL log_row_value_options="partial_json";