definition takes up space. On a magnetic tape that definition takes the form of an inter-record gap. On a disk a meta data area must be allocated. This is minimal in a file where all the records are the same length. On a file composed of varying length records a maximum record length is defined to determine the size of the length metadata associated with each record. See also Stream (computing) Data set (IBM mainframe) Files-11 CMS file system ISAM/VSAM Distributed Data Management Architecture (DDM) Record-oriented file (DDM) References Computer file systems