Changing the OSAM block size for a HALDB database data set
The OSAM block size for a HALDB database data set is stored in the RECON data set.
You can change it using either the HALDB Partition Definition
utility (%DFSHALDB) or the BLOCKSZE(nnnnn) parameter
of the DBRC batch command CHANGE.PART. After you
change the OSAM block size of a data set, the partition initialization
needed (PINIT) flag is set for the partition.