Note
- For V4.2.x, this parameter is available starting with V4.2.0.
- For V3.x, this parameter is available starting with V3.1.5.
Description
The datafile_maxsize parameter specifies the maximum size to which a disk file can be automatically expanded.
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 |
|---|---|
| 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
The default value of datafile_maxsize is 0, indicating that disk file auto-expansion is disabled. If you want to enable auto-expansion, set datafile_maxsize to a non-zero value:
The value of
datafile_maxsizemust be greater than the current disk space occupied by the data file (datafile_sizeordatafile_disk_percentage). If the set value is smaller than the current disk space occupied by the data file, auto-expansion will not be triggered.If the value of
datafile_maxsizeexceeds the maximum available disk space, the actual available disk space will be used as the maximum value.
Examples
Set the maximum size to which a disk file can be automatically expanded to 10G.
obclient> ALTER SYSTEM SET datafile_maxsize = '10G';