Note
For OceanBase Database V4.2.x, this parameter was introduced in OceanBase Database V4.2.5.
Description
unit_gc_wait_time specifies the maximum time to wait for triggering unit garbage collection (GC). When the specified wait time elapses, GC is forcibly performed.
Limitations
Query the parameter
In the
systenant or a user tenant, you can execute theSHOW PARAMETERSstatement to query the parameter or query theGV$OB_PARAMETERSview for the parameter.Modify the parameter
You can modify the parameter only in the
systenant.
Attributes
| Attribute | Description |
|---|---|
| Type | Time |
| Default value | 1m, which indicates 1 minute. |
| Value range | [0, 30d] |
| 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
You can set this parameter to a value with a unit of µs (microsecond), ms (millisecond), s (second), m (minute), h (hour), or d (day).
Examples
Set the maximum time to wait for triggering unit GC to 1 minute. When the wait time exceeds 1 minute, the system forcibly triggers GC.
obclient> ALTER SYSTEM SET unit_gc_wait_time = '1m';