Table data is compressed at the block level.
You cannot specify this option to modify the definitions of global temporary tables or volatile tables.
For Object File System tables, BLOCKCOMPRESSION has a default setting that you cannot change.
For details, see BLOCKCOMPRESSION (CREATE TABLE).
- AUTOTEMP
- The file system determines the block-level compression setting for the table.
- MANUAL
- Block-level compression is applied based on the default for the table at the time the table is created. You can override these values using SET QUERY_BAND. See Example: Using the BLOCKCOMPRESSION Reserved Query Band.
- ALWAYS
- The table and its subtables are block-level compressed, even if a query band indicates otherwise.
- NEVER
- The table and its subtables are not block-level compressed, even if a query band indicates otherwise.
- DEFAULT
- This is set by the system.
BLOCKCOMPRESSIONALGORITHM
Specifies the algorithm to use for block-level compression (BLC).
This option only applies when the effective BLOCKCOMPRESSION is MANUAL, AUTOTEMP, or ALWAYS.
- ZLIB
- Block-level compression using the zlib software algorithm.
- ELZS_H
- Block-level compression using a hardware compression engine board in every system node.
- DEFAULT
- This is set by the system.
BLOCKCOMPRESSIONLEVEL
Specifies a value to indicate a preference for compression speed or compression effectiveness. This option only applies when the BLOCKCOMPRESSIONALGORITHM option is set to ZLIB. Although this option is accepted in combination with BLOCKCOMPRESSIONALGORITHM = ELZS_H, this option is ignored. If BLOCKCOMPRESSIONALGORITHM is altered to ZLIB, this option takes effect.
- value
- Integer from 1 through 9, where 1 specifies the least processor-intensive compression speed with the lowest compression ratio and 9 specifies the most processor-intensive compression speed with highest compression ratio.
- DEFAULT
- This is set by the system.