Note
For V3.1.4, this parameter is available starting with V3.1.4.
Description
In Shared-Nothing (SN) mode, the
datafile_nextparameter specifies the growth step of automatic disk file expansion.In Shared-Storage (SS) mode, the value of the
datafile_nextparameter is meaningless and can be modified, but the modification will not take effect.
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
Only the
systenant can modify this parameter. User tenants cannot modify this parameter.
Attributes
| Attribute | Description |
|---|---|
| Parameter type | Capacity |
| Default value | 0 |
| Value range | [0M, +∞) |
| 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
In SN mode, the default value of datafile_next is 0, which means that disk file auto-expansion is not enabled. To enable auto-expansion, you need to set a new value:
- If
datafile_nextis set to a value less than 1G, the value is min (1G, datafile_maxsize * 10%). - If
datafile_nextis set to a value greater than 1G, the value is min ( datafile_next, remaining disk space).
Examples
In SN mode, set the growth step of automatic disk file expansion to 10G.
obclient> ALTER SYSTEM SET datafile_next = '10G';