Note
This parameter was introduced in OceanBase Database V4.2.0.
Description
range_optimizer_max_mem_size specifies the maximum memory space available for the Query Range module.
Attributes
| Attribute | Description |
|---|---|
| Type | Capacity |
| Default value | 128M |
| Value range | [0M, )
NoteThe value range of this parameter has been changed from [16M, 1G] to [0M, ) since OceanBase Database V4.3.0. |
| Modifiable | Yes. You can use the ALTER SYSTEM SET statement to modify the parameter. |
| Effective upon OBServer node restart | No |
Considerations
This parameter limits the memory usage of the Query Range module. When the memory used by the Query Range module reaches the specified value, the system no longer extracts a query range. For example, if a complex predicate hits an index and the memory used to extract the query range for the predicate reaches the specified value, the system does not select the index and tries to access the primary table.
Example
obclient> ALTER SYSTEM SET range_optimizer_max_mem_size = '128M';