Data Set (IBM Mainframe)
data set (archaic), dataset (preferred), is a computer file having a record organization. The term pertains to the IBM mainframe operating system line, starting with OS/360, and is still used by its successors, including the current z/OS. Those systems historically preferred this term over a file. A dataset is typically stored on direct access storage device (DASD) or magnetic tape, however unit record devices are also supported.
Datasets are not unstructured streams of bytes, but rather are organized in various logical record and block structures determined by the DSORG (data set organization), RECFM (record format), and other parameters. These parameters are specified at the time of the data set allocation (creation), for example with the Job Control Language DD statements. Inside a job they are stored in the Data Control Block (DCB), which is a data structure used to access datasets, for example using access methods.
Read more about Data Set (IBM Mainframe): Dataset Organization, Record Format (RECFM), Partitioned Datasets
Famous quotes containing the words data and/or set:
“To write it, it took three months; to conceive it three minutes; to collect the data in it—all my life.”
—F. Scott Fitzgerald (1896–1940)
“She’s just a child,
but I’m the one who’s fainthearted.
She’s the woman,
but I’m the coward.
She bears that high, swollen set of breasts,
but I’m the one who’s burdened.
The heavy hips are hers,
but I’m unable to move.
It’s a wonder
how clumsy I’ve become
because of flaws
that shelter themselves
in another.”
—Amaru (c. seventh century A.D.)