Purpose
Determines whether compression operations favor processing speed or degree of data compression.
Field Group
Compression
Valid Range
1 through 9
A setting of 1 maximally favors speed of compression operation over degree of data compression. A setting of 9 maximally favors degree of data compression over speed of compression operation.
Default
6
The default provides a balance between speed of compression operation and degree of data compression.
Changes Take Effect
After the DBS Control Record has been written. Changed setting applies to new data added to tables. Compression for existing data is not changed until that data is modified.
Usage Notes
BLC enables data compression at the data block (DB) level of the Teradata Database file system. Compression reduces the amount of storage required for a given amount of data. The BlockLevelCompression field of DBS Control enables and disables BLC.
Related Topics
| For more information on... | See... |
|---|---|
| BlockLevelCompression field | BlockLevelCompression. |
| COMPRESS and UNCOMPRESS commands | Ferret Utility (ferret). |
| BLOCKCOMPRESSION query band | SQL Data Definition Language - Syntax and Examples. |