Note
For V4.6.0, this parameter is available starting with V4.6.0.
Description
px_target_low_watermark specifies the percentage threshold of the low watermark for the number of parallel threads. When the threshold is exceeded, the system starts to downgrade the parallelism of new DFOs to avoid exhausting CPU resources.
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 | Int |
| Default value | 60 |
| Value range | [0, 100] |
| 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 value of the px_target_low_watermark parameter must satisfy the following condition:
px_target_low_watermark <= px_target_high_watermark <= px_target_workers_per_cpu
Examples
Set the percentage threshold of the low watermark for the number of parallel threads to 5.
obclient> ALTER SYSTEM SET px_target_low_watermark = 5;