Changing the castout threshold values

Use the ALTER GROUPBUFFERPOOL command to change the group buffer pool castout thresholds.

The CLASST option can be expressed as a percentage of the number of data entries or an absolute number of pages. The GBPOOLT option is expressed as a percentage of the number of data entries.

Examples

The following command, for example, changes the class castout threshold to 15% and the group buffer pool threshold to 55%:

Begin general-use programming interface information.
-DB1A ALTER GROUPBUFFERPOOL(GBP1) CLASST(15,0) GBPOOLT(55)
End general-use programming interface information.

The following command, for example, changes the class castout threshold to 2500 pages and the group buffer pool threshold to 40%:

Begin general-use programming interface information.
-DB1A ALTER GROUPBUFFERPOOL(GBP1) CLASST(0,2500) GBPOOLT(40)
End general-use programming interface information.

These changes take effect immediately.