The SPACE parameter supports allocation for records. The AVGREC keyword lets you specify a unit (or scale), such as bytes, KBs, or MBs, and an average record size. Primary and secondary space values are expressed in terms of the number of records expected initially and from update activity. If you specify BLKSIZE=0 or omit BLKSIZE, the system calculates the most space-efficient block size based on the volume selected.