PERCENT FREE FOR UPDATE field (PCTFREE_UPD subsystem parameter)
The PCTFREE_UPD subsystem parameter specifies the default value to use for the PCTFREE FOR UPDATE clause of CREATE TABLESPACE or ALTER TABLESPACE statements. It specifies the default amount of free space to reserve on each page for use by subsequent UPDATE operations when data is added to the table by INSERT operations or utilities.
| Acceptable values: | AUTO, 0–99 |
|---|---|
| Default: | 0 |
| Update: | option 15 on panel DSNTIPB |
| DSNZPxxx: | DSN6SPRM.PCTFREE_UPD |
| Data sharing scope: | The recommendation is to use the same value on all members. |
This value is used as the default FOR UPDATE value when no PCTFREE FOR UPDATE clause is specified for a CREATE TABLESPACE or ALTER TABLESPACE statement.
- AUTO
- Db2 uses real-time statistics values to automatically calculate the percentage of free space that is to be used by update operations. This value is equivalent to specifying PCTFREE FOR UPDATE -1 in the CREATE TABLESPACE or ALTER TABLESPACE statement.
- 0–99
- Db2 reserves the specified percentage of space for use by update operations.