Note
This parameter was introduced in OceanBase Database V4.3.3.
Description
The ob_encoding_granularity parameter specifies the maximum number of rows per microblock for encoding.
Privilege requirements
Query the parameter
Both the
systenant and all user tenants can execute theSHOW PARAMETERSstatement or query theGV$OB_PARAMETERSview to retrieve the value of this parameter.Modify the parameter
Both the
systenant and user tenants can modify this parameter.
Attributes
| Attribute | Description |
|---|---|
| Type | Int |
| Default value | 65536 |
| Value range | [8192, 1048576] |
| Modifiable | Yes. You can modify this parameter by using the ALTER SYSTEM SET statement. |
| Effective upon OBServer node restart | No. The setting takes effect immediately. |
Considerations
When there are only a few updates in AP business scenarios, if the number of rows in a microblock is too large, it is difficult to use skip index acceleration for filtering or to reuse microblocks during major compaction, which results in poor major compaction performance. In this case, you can decrease the value of this parameter to improve performance.
Example
Set the maximum number of rows per microblock for encoding to 8192.
obclient> ALTER SYSTEM SET ob_encoding_granularity=8192;