In contrast to non-VSAM data sets, VSAM data sets are formatted differently. The VSAM data sets consist of collections of records that are grouped into CI (control intervals). VSAM stores its records within the control interval, which is a fixed portion of storage space. The maximum length of a VSAM record is 1 cylinder. In VSAM, records are arranged according to the index key, the relative record number or the relative byte address.
