The SET_CONSUMER_GROUP_MAPPING procedure is used to add, delete, or modify entries that map sessions to resource groups based on session-based login and runtime attributes.
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. In the current version, only the USER (database username), COLUMN, and FUNCTION attributes are supported. OceanBase Database performs tasks such as major compactions, minor compactions, DDL KV compactions, data completion, backup, and restore 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 of OceanBase Database. This way, the resources of background tasks are limited to their corresponding resource groups. |
| value | The value to match, including absolute mapping and regular expressions. |
| consumer_group | The name of the consumer group to map to. If 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 of 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 describes the predefined FUNCTION resource group mapping rules in OceanBase Database. You can use the DBMS_RESOURCE_MANAGER.SET_CONSUMER_GROUP_MAPPING procedure to modify or delete these mapping rules.
| 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 cleanup tasks. |
| FUNCTION | DDL | Corresponds to unique index validation, column deletion, and data completion operations. |
| FUNCTION | DDL_HIGH | Corresponds to the dumping of DDL MemTables. |
| FUNCTION | CLOG_HIGH | Corresponds to clog log commit tasks. |
| FUNCTION | OPT_STATS | Corresponds to statistics collection tasks. |
| FUNCTION | MVIEW | Corresponds to the use of I/O and CPU resources for incremental refresh of materialized views and MLOG purge. |
Examples
obclient> CALL DBMS_RESOURCE_MANAGER.SET_CONSUMER_GROUP_MAPPING(
attribute => 'COLUMN' ,
value => 't2.c3 = 3 for user1',
consumer_group => 'group1');
Query OK, 0 rows affected