Used by the selected compression algorithm. Determines whether compression operations favor processing speed or degree of data compression.
CompressionLevel is ignored if CompressionZLIBMethod is set to ISAL.
Field Group
Compression
Valid Range
For ZLIB and IPPZLIB, valid range values are from 1 through 9.
A setting of 1 indicates preference for maximum compression speed. Each higher value sacrifices more speed for better compression ratio. A setting of 9 optimizes for minimal compression size.
Default
1
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 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 Information
| For more information on... | See... |
|---|---|
| BlockLevelCompression field | BlockLevelCompression. |
| COMPRESS and UNCOMPRESS commands | Ferret Utility (ferret). |
| BLOCKCOMPRESSION query band | Teradata Vantage™ - SQL Data Definition Language Syntax and Examples, B035-1144. |