Purpose
Determines whether the AutoCylPack (automatic background cylinder packing) task is restricted to packing data, unpacking data, or if it is unrestricted, and can both pack and unpack data to achieve the target free space percentage (FSP) on a cylinder.
The AutoCylPack task can pack cylinder data more tightly, to store more data on fewer cylinders. This can improve the efficiency of performing sequential scans of tables and also frees up cylinders to be used elsewhere.
Alternatively, the AutoCylPack task can unpack cylinder data, to free more space on a cylinder. This can improve the speed of updates to tables occupying those cylinders, at the cost of consuming more cylinders for the given amount of data.
Field Group
File System
Valid Settings
| Setting | Description |
|---|---|
| 1 | AutoCylPack is restricted to packing data more tightly on cylinders. |
| 2 | AutoCylPack is unrestricted, so can both pack and unpack data as necessary to achieve the target FSP. |
| 3 | AutoCylPack is restricted to unpacking data, arranging it more loosely on and between cylinders. |
Default
2
Changes Take Effect
After the DBS Control Record has been written.
Related Topics
| For more information on… | See… |
|---|---|
| AutoCylPack | DisableAutoCylPack. |
| Free Space Percent | FreeSpacePercent, SHOWFSP, Database Administration. |