For Object File System tables, BLOCKCOMPRESSION has a default setting that you cannot change.
The BLOCKCOMPRESSION option applies only to permanent tables (except permanent journal tables).
When you change the value of BLOCKCOMPRESSION, Vantage does not change the compression status of data blocks that existed before the change. Therefore, a table may have both compressed and uncompressed data blocks. Changing the value of BLOCKCOMPRESSION affects only new data blocks.
The BLOCKCOMPRESSION option cannot be used with the IMMEDIATE clause.