The SET_CONSUMER_GROUP_MAPPING procedure adds, deletes, or modifies entries that map sessions to resource groups based on session login and runtime attributes.
Applicability
This topic applies only to OceanBase Database Enterprise Edition. OceanBase Database Community Edition provides only MySQL mode.
Syntax
DBMS_RESOURCE_MANAGER.SET_CONSUMER_GROUP_MAPPING(
attribute IN VARCHAR2,
value IN VARCHAR2,
consumer_group IN VARCHAR2 DEFAULT NULL);
Parameters
| Parameter | Description |
|---|---|
| attribute | The attribute to add or modify. The current version supports only USER (the database username), COLUMN, and FUNCTION. OceanBase Database performs tasks such as major compactions, backup and restore, and data completion in the background. These tasks are not user-initiated and may consume CPU and I/O resources of other users and tasks. Therefore, you can specify FUNCTION mappings for different background tasks to limit their resources to the corresponding resource groups. |
| value | The attribute value to match, including absolute mappings and regular expressions. |
| consumer_group | The name of the consumer group to map to. If this parameter is NULL, the mapping is deleted. |
Considerations
If no mapping exists for the specified attribute and value, a mapping to the specified consumer group is created. If a mapping already exists for the specified attribute and value, the consumer group in the mapping is updated to the specified consumer group. If the consumer_group parameter is NULL, any mapping for the specified attribute and value is deleted.
The following table lists the predefined FUNCTION resource group mappings in OceanBase Database. You can use the DBMS_RESOURCE_MANAGER.SET_CONSUMER_GROUP_MAPPING procedure to modify or delete these mappings.
| Attribute | Value | Description |
|---|---|---|
| FUNCTION | COMPACTION_HIGH | Corresponds to MINI_MERGE and DDL KV merge tasks. |
| FUNCTION | COMPACTION_MID | Corresponds to MINOR_MERGE tasks. |
| FUNCTION | COMPACTION_LOW | Corresponds to MAJOR_MERGE tasks. |
| FUNCTION | HA_HIGH | Corresponds to replication, rebuild, and restore tasks. |
| FUNCTION | HA_MID | Corresponds to migration tasks. |
| FUNCTION | HA_LOW | Corresponds to backup and backup cleanup tasks. |
| FUNCTION | DDL | Corresponds to unique index validation and column deletion with data filling. |
| FUNCTION | DDL_HIGH | Corresponds to DDL MemTable dump tasks. |
| FUNCTION | CLOG_HIGH | Corresponds to clog log commit tasks. |
| FUNCTION | OPT_STATS | Corresponds to statistics collection tasks. |
Examples
obclient> BEGIN
DBMS_RESOURCE_MANAGER.SET_CONSUMER_GROUP_MAPPING(
attribute => 'COLUMN' ,
value => 't2.c3 = 3 for user1',
consumer_group => 'group1');
END ;