Determines whether block-level compression (BLC) compression ratio information is gathered by COLLECT STATISTICS statements, and can be displayed by the SHOW STATISTICS statement.
Field Group
Optimizer Statistics
Valid Settings
| Setting | Effect |
|---|---|
| 0 | Indicates field is set or has been reset to the Teradata default (enabled). Equivalent to a setting of 1. |
| 1 | Enabled. BLC statistics are collected if BLC is enabled. |
| 2 | Disabled. BLC statistics are not collected. |
Default
0 (enabled)
Changes Take Effect
After the DBS Control Record has been written.
Usage Notes
If BLC is enabled but BLC statistics are not wanted, set this field to 2 to reduce overhead of collecting such statistics on tables eligible for BLC.
The Ferret utility SHOWBLOCKS command also provides information on estimated compression ratios for BLC.
Related Information
| For more information on... | See... |
|---|---|
| COLLECT STATISTICS and SHOW STATISTICS statements | Teradata Vantage™ - SQL Data Definition Language Syntax and Examples, B035-1144. |
| Enabling and disabling block-level compression | BlockLevelCompression. |
| The Ferret Utility | Ferret Utility (ferret) |