The address book doesn't work as well as it used to. Physically, all VSAM data sets consist of control intervals and control areas . The control interval is determined by the type of disk device used for the data set. It is also the unit for transferring data in and out of memory. Several control intervals are grouped together to form a control area , and one or more control areas form the VSAM data set.
Control areas are usually one track to one cylinder in size.
Depending on control statements, other DD statements may be required. Control statements may begin anywhere in columns 2 - 72. Control statement parameters are separated by spaces. To continue a control statement, code a hyphen after its last parameter. Notes Cluster NAME must be a standard OS name.