Purpose
Specifies the minimum size DB that will be compressed. DBs smaller than this size will not be compressed, because the overhead of having to compress and uncompress the blocks during DML operations is not worth the minimal space savings that might be achieved.
Field Group
Compression
Valid Range
2 through 255 sectors
Default
16
Changes Take Effect
After the DBS Control Record has been written.
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.
Compression is also subject to the criteria specified by the MinPercentCompReduction DBS Control field. DBs not meeting these minimum criteria will not be compressed, even if they are larger than the size specified by MinDBSectsToCompress.
The PermDBSize and JournalDBSize field settings in DBS Control apply to the uncompressed size of these types of DBs.
Related Topics
| For more information on... | See... |
|---|---|
| BlockLevelCompression field | BlockLevelCompression. |
| COMPRESS and UNCOMPRESS commands | Ferret Utility (ferret). |