The Sort/Merge utility is a mainframe program to sort records in a file into a specified order, merge pre-sorted files into a sorted file, or copy selected records. Internally, these utilities use one or more of the standard sorting algorithms, often with proprietary fine-tuned code.
Mainframes were originally supplied with limited main memory by today's standards and the amount of data to be sorted was frequently very large. Because of this, unlike more recent sort programs, early Sort/Merge programs placed great emphasis on efficient techniques for sorting data on secondary storage, typically tape[a] or disk. In 1968 the OS/360 Sort/Merge program provided five different "sequence distribution techniques" that could be used depending on the number and type of devices available.[1]
Historically, the "alias" SORT has been used to refer to an installation's preferred sort program, IBM's Sort/Merge, and third party Sort/Merge programs (i.e., SYNCSORT, CASORT). DFSORT is often referred to by its program name, ICEMAN (component ICE; the original OS/360 Sort/Merge program name was IERRCO00, component IER, also with "alias" SORT).
Cite error: There are <ref group=lower-alpha> tags or {{efn}} templates on this page, but the references will not show without a {{reflist|group=lower-alpha}} template or {{notelist}} template (see the help page).