Specifies whether the the COLLECT STATISTICS statement calculates the estimated BLC compression factor for tables. The compression factor is calculated as uncompressed size/compressed size.
The BLC compression factor is used to calculate the customer data space (CDS), which is the logical size of customer data: the size of the uncompressed primary data, excluding the size of fallback data.
Field Group
Optimizer Statistics
Valid Settings
| Setting | Effect |
|---|---|
| 0 | Disable BLC compression factor calculation for COLLECT STATISTICS. |
| 1 | Enable BLC compression factor calculation for COLLECT STATISTICS. |
Default
0 (disabled)
Changes Take Effect
After the DBS Control Record has been written.
Usage Notes
To enable the CDS feature, set this field to 1, BlockLevelCompression to ON, and BLCStats to 0.
Related Information
| For more information on... | See... |
|---|---|
| CDS macros that let you find the CDS sizes of objects, databases, and systems | SystemFE Macros, B035-1103. |
| Enabling and disabling block-level compression | BlockLevelCompression. |