datafile_size|V4.3.5|OceanBase Database| docs|Distributed Database

datafile_size

Last Updated：2026-04-09 02:53:56 Updated

This parameter was introduced in V2.2.50.

Description

In shared-nothing (SN) mode, the datafile_size parameter specifies the size of data files.
In shared-storage (SS) mode, the datafile_size parameter specifies the size of local cache space.

Query privilege

Tenants in the sys tenant and all user tenants can use the SHOW PARAMETERS statement or the GV$OB_PARAMETERS view to query this parameter.
Modify privilege

Only the sys tenant can modify this parameter. User tenants are not allowed to modify it.

Attribute	Description
Type	Capacity
Default value	0M. The default unit is MB. Specify the unit when you modify the parameter.
Value range	[0M, +∞)
Modifiable	Yes. You can use the `ALTER SYSTEM SET` statement to modify it.
Effective upon OBServer node restart	No. The setting takes effect immediately.

Once this parameter is set, it can only be increased and cannot be decreased.
If this parameter and datafile_disk_percentage are configured, the value of this parameter takes precedence. For more information about datafile_disk_percentage, see datafile_disk_percentage.

In shared-storage mode, set the size of data files to 80 GB.

obclient> ALTER SYSTEM SET datafile_size='80G';