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 data file can automatically expand.
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, which indicates that automatic expansion is not enabled. |
| 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
datafile_maxsize defaults to 0, which means automatic expansion is disabled. To enable it, set the value to a non-zero value:
The value of
datafile_maxsizemust be greater than the current size of the data file (datafile_sizeordatafile_disk_percentage). If the value is less than the current size of the data file, automatic expansion will not be triggered.If the value of
datafile_maxsizeexceeds the maximum available space on the disk, the actual available space on the disk will be used as the maximum value.
Examples
Set the maximum size to which a data file can automatically expand to 10 GB.
obclient> ALTER SYSTEM SET datafile_maxsize = '10G';