Note
This parameter is available starting with V2.2.50.
Overview
The datafile_disk_percentage parameter specifies the percentage of total disk space that data files can occupy (the disk where the data_dir is located will be initialized by the OceanBase database system for data storage).
Privilege requirements
Query parameters
Both the
systenant and all user tenants can query this parameter using theSHOW PARAMETERSstatement or theGV$OB_PARAMETERSview.Modify parameters
Only the
systenant can modify this parameter. User tenants cannot modify it.
Attributes
Attribute |
Description |
|---|---|
| Parameter type | Int |
| Default Value | 0
NoteStarting from V4.0.0, the default value has been adjusted from 90 to 0. |
| Value range | [0,99]
NoteStarting from V4.0.0, the value range has been adjusted from [5,99] to [0,99]. |
| Modifiable | Yes, you can use the following methods:ALTER SYSTEM SETStatement modification. |
| Whether to Restart the OBServer Node for the Change to Take Effect | No. The setting takes effect immediately. |
Usage instructions
When the value of this parameter is 0, the system automatically calculates the percentage of total disk space occupied by data files based on whether logs and data share the same disk.
- When shared, the data files occupy 60% of the total disk space where they are located.
- During exclusive access, the data file occupies 90% of the total disk space where it resides.
If this parameter is configured together with
datafile_size, the value set bydatafile_sizeshall prevail. For more information aboutdatafile_size, see datafile_size.
Configuration example
Set the data file to occupy 90% of the total disk space where it resides.
obclient> ALTER SYSTEM SET datafile_disk_percentage=90;