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Guy Harris (talk | contribs) →Generation Data Group: Explicitly mention that OS/360 and DOS/360 have successors. |
Guy Harris (talk | contribs) →Generation Data Group: Clean up the merge. (Note: see the history of z/OS for the attribution for text copied from that page.) |
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An individual member of the GDG collection is called a "''Generation Data Set''."<ref name=G.sets/><ref>"A generation data set is one of ...</ref> The latter may be identified by an absolute number, {{code|ACCTG.OURGDG(1234)}}, or a relative number: {{code|(-1)}} for the previous generation, {{code|(0)}} for the current one, and {{code|(+1)}} the next generation.<ref>{{cite web
|url=http://mainframewizard.com/content/what-gdg |title=What is a GDG?}}</ref>
A
The purpose of GDGs is to automate archival, using the command language [[Job Control Language|JCL]], the
(0) is the most recent version▼
(-1), (-2), ... are previous generations▼
(+1) a new generation (see DD)▼
Another use of GDGs is to be able to address all generations simultaneously within a JCL script without having to know the number of currently available generations. To do this, you have to omit the parentheses and the generation number in the JCL when specifying the dataset.▼
===GDG JCL & features===
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|title=IDCAMS – Create and delete GDG base using JCL
|url=http://code.xmlgadgets.com/2011/05/16/idcams-create-and-delete-gdg-base/comment-page-1}}</ref>
▲A Generation Data Group (GDG) is a description of how many generations of a file are to be kept and at what age a generation will be deleted. Whenever a new generation is created, the system checks whether one or more obsolete generations are to be deleted.
▲The purpose of GDGs is to automate archival, using the command language [[Job Control Language|JCL]], the file name given is generic. When DSN appears, the GDG name appears along with the history number, where
▲(0) is the most recent version
▲(-1), (-2), ... are previous generations
▲(+1) a new generation (see DD)
▲Another use of GDGs is to be able to address all generations simultaneously within a JCL script without having to know the number of currently available generations. To do this, you have to omit the parentheses and the generation number in the JCL when specifying the dataset.
====Example====
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