Note
For V4.6.0, this parameter is available starting with V4.6.0.
Description
enable_window_compaction specifies whether to enable window compaction for the current tenant.
Privilege requirements
Query the parameter
The
systenant and all user tenants can use theSHOW PARAMETERSstatement or theGV$OB_PARAMETERSview to query this parameter.Modify the parameter
The
systenant and user tenants can modify this parameter.
Attributes
| Attribute | Description |
|---|---|
| Type | Bool |
| Default value | False |
| Value range |
|
| Modifiable | Yes. You can use the ALTER SYSTEM SET statement to modify the parameter. |
| Effective upon OBServer node restart | No. The setting takes effect immediately. |
Considerations
The enable_window_compaction parameter and the DAILY_MAINTENANCE_WINDOW window compaction task jointly control window compaction. The following table describes the relationships between the values of these two parameters and the daily compaction behavior.
| enable_window_compaction | DAILY_MAINTENANCE_WINDOW | Daily compaction behavior |
|---|---|---|
| False | False(CALL DBMS_SCHEDULER.DISABLE('DAILY_MAINTENANCE_WINDOW');) |
Triggers daily tenant compaction. |
| False | True(CALL DBMS_SCHEDULER.ENABLE('DAILY_MAINTENANCE_WINDOW');) |
Triggers daily tenant compaction. |
| True | False (CALL DBMS_SCHEDULER.DISABLE('DAILY_MAINTENANCE_WINDOW');) |
No compaction is triggered. |
| True | True(CALL DBMS_SCHEDULER.ENABLE('DAILY_MAINTENANCE_WINDOW');) |
Triggers window compaction. |
Examples
Enable window compaction for the user tenant.
obclient> ALTER SYSTEM SET enable_window_compaction = True;
References
For more information about window compaction, see Window compaction.
