Limit of GDG reached

amar143 · New User Joined: 11 Nov 2010 Posts: 4 Location: India

If limit of GDG(255) reached and I want to create another 100 generations, How can i create that? And what will happen with older 255 generations.

Robert Sample · Posted: Mon May 21, 2012 7:18 pm

1. The theoretical limit of cataloged generations is 255 generations -- the actual limit will depend upon how the GDG was defined.
2. The actual generation number can go up to 9000 (i.e., G8999V00 is a valid generation number).
3. Assuing you created a GDG with LIMIT(255) and you add 100 generations, then the normal processing will occur -- the oldest 100 generations will be removed from the catalog (disposition depending upon a variety of factors, such as whether or not the GDG is SMS-managed, whether the GDG was defined with ERASE and so forth) and the new 100 generations will be in the catalog. The catalog would start with G0001V00 through G0255V00 and wind up with G0101V00 through G0355V00.

Since you seem completely and totally clueless about generation data groups, why don't you tell us the actual problem you THINK you have and let us help you clarify it?

Peter cobolskolan · Posted: Mon May 21, 2012 7:50 pm

You can use IDCAMS and ALTER to give the GDG a new LIMIT(), if the limit is incorrect, otherwise as Robert suggested.

amar143 · New User Joined: 11 Nov 2010 Posts: 4 Location: India

Thanks very much Robert for your clarification, There is no practical scenario I am facing with but According to theoretical description, I come to know that limit of GDG creation is 255 so I had that doubt. Now what will happen, if generations goes beyond 9000 (i.e., G8999V00 is a valid generation number).

Robert Sample · Posted: Wed May 23, 2012 4:44 pm

amar143, this is NOT a manual reading service. Please find the JCL User's Guide (hint: there's a button at the top of THIS page that will let you review it) and read Appendix B on Generation Data Sets to find the answer to your question.

Phrzby Phil · Posted: Wed May 23, 2012 6:00 pm

Or - Experiment!!

That's not just a chemistry exercise.

You might just become your site's expert. (Then you'll be cited.)

Anuj Dhawan · Posted: Wed May 23, 2012 7:01 pm

Pete Wilson · Posted: Sat May 26, 2012 7:30 pm

should we mention versions!

You'll find they go up to G9999V00 and then back to G0001V00 again. If you have both of those generation existing and you reference the (0) relative generation it would be to G0001V00 and G9999V00 would be (-1).