What is version number of a generation

akashs · New User Joined: 24 Nov 2005 Posts: 49 Location: chennai

Hi,

In an interview ,they asked me when the version number of a particular
generation changes..plz explain in detail...

regards,
akash

aklima · New User Joined: 25 Nov 2005 Posts: 18 Location: uae

well the version number changes when a new generation is created. ex if we create for suppose an year then let us start with month jan when it was the new one then it was given as +1 then when feb was created then it became 0 as now feb is +1it goes on from 0 to negative value until it gets deleted or scrached.
i hope this might be the answer u needed
bye

mmwife · Super Moderator Joined: 30 May 2003 Posts: 1592

There's been a great deal of misuse of GDG terms in this forum, so it's important to get the definitions straight before we begin.

A Generation Data Group is a collection of Generation Datasets. A Generation Dataset can have more than one Version, but only one version for each Generation Dataset can exist at any given time.

For e.g. Gen Dataset X.Y.Z.G0006V00 can be replaced by X.Y.Z.G0006V01 but G0006V00 will no longer exist after G0006V01 is created.

So given these definitions, a new version can be created as below:

Suppose you find that a daily job was run with the wrong parm 3 days ago. The subsequent 2 days were run correctly, but the O/P of day1 is NG. So now your GDG looks like this:
.
.
.
X.Y.Z.G0031V00 (NG dataset)
X.Y.Z.G0032V00
X.Y.Z.G0033V00

To maintain the integrity of the GDG you can recreate Gen 31 by rerunning the job like this:

//s1 exec pgm=thepgm,parm=goodparm'
//OPFILE dd dsn=X.Y.Z.G0031V01,...

When the job ends the GDG looks like this:
.
.
.
X.Y.Z.G0031V01 (recreated dataset)
X.Y.Z.G0032V00
X.Y.Z.G0033V00

P.S. If you want to you can copy the bad generation before you start the recreation, JIC.