Data set (IBM mainframe): Difference between revisions

Revision as of 10:28, 8 February 2007

Revision as of 07:24, 9 February 2007

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The term '''data set''' or '''dataset''' is used to refer to [[computer file|file]]s on an [[IBM]] [[mainframe computer]], typically stored on [[Direct access storage device|DASD]] or [[magnetic tape]]. They are [[record-oriented file]]s. The term pertains to the IBM mainframe operating systems starting with [[OS/360]], and continued to be used through later systems based on that heritage, [[MVS]] system, [[OS/390]], and [[z/OS]].

Unlike files on [[Unix|UNIX]] systems, they are not unstructured streams of [[byte]]s but rather are organized in various logical record and block structures determined by the DSORG (data set organization) and RECFM (record format) parameters of the DCB (Data Control Block). The [[Data Control Block|DCB]] is a data structure used to access datasets. These parameters may also be specified in the Job Control Language [[Job Control Language|JCL]] DD statements that are used to allocate them.

== Dataset Organization ==