Purpose
Specifies whether Teradata Database should automatically determine an appropriate data change threshold for statistics recollection.
This field is used only if the DefaultUserChangeThreshold setting is disabled (set to zero) when a COLLECT STATISTICS SQL statement does not specify the USING THRESHOLD PERCENT option.
Field Group
Optimizer Statistics
Settings
| Value | Description |
|---|---|
| 0 | Use factory default, currently equivalent to setting 1. |
| 1 | Enables system-determined change threshold checking in statistics collection when DBQL ObjectUsage (update/delete/insert counts) is enabled. |
| 2 | Enables system-determined change threshold checking in statistics collection regardless of ObjectUsage setting in DBQL logging options. |
| 3 | Disables system-determined change threshold. |
Default
0
Changes Take Effect
After the DBS Control Record has been written.
Usage Notes
Statistics are used by the optimizer to improve query performance.
When cost profiles are in effect, this setting can be overridden by a cost profile constant value.
Related Topics
| For more information on… | See… |
|---|---|
| Optimizer statistics fields | |
| Cost profiles |
|