Note
This variable is available starting with V4.3.5 BP1.
Description
ob_ivf_nprobes specifies the number of nearest cluster centers to search during a vector index query. This variable affects the performance and recall rate of IVF queries: a larger value results in a higher recall rate but also increases the search time.
Applicability
This variable applies only to OceanBase Database in MySQL-compatible mode.
Privilege requirements
Query variables
- The
systenant and all user tenants can execute theSHOW VARIABLESstatement or query theinformation_schema.SESSION_VARIABLESview (MySQL-compatible mode) to view the values of session system variables.
- The
Modify variables
- The
systenant and all MySQL user tenants can directly modify the values of session system variables in their own tenants.
- The
Attributes
| Attribute | Description |
|---|---|
| Type | Int |
| Default value | 8 |
| Value range | [1,65536] |
| Scope | Session |
| Modifiable | Yes. You can execute the SET statement to modify the value. |
Examples
Set the number of nearest cluster centers to search during this query to 10.
obclient> SET ob_ivf_nprobes = 10;