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
datafile_maxsize specifies the maximum size of the space to be automatically expanded for the disk file.
Privilege requirements
Query the parameter
The
systenant and all user tenants can query this parameter by using theSHOW PARAMETERSstatement or theGV$OB_PARAMETERSview.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
In SN mode, the default value of datafile_maxsize is 0, which indicates that the automatic expansion of the disk file is not enabled. If you want to enable the automatic expansion, set datafile_maxsize to a value other than 0:
The value of
datafile_maxsizemust be greater than the size of the disk space occupied by the data file (datafile_sizeordatafile_disk_percentage). If the value is less than the size of the disk space occupied by the data file, the automatic expansion is not triggered.If the value of
datafile_maxsizeexceeds the maximum available space on the disk, the maximum value is the actual available space on the disk.
Examples
Set the maximum size of the space to be automatically expanded for the disk file to 10G.
obclient> ALTER SYSTEM SET datafile_maxsize = '10G';