Increasing GDG limit without IDCAMS.

[Sonam Choudhary]

Hello,

Can we increase the limit of a GDG to more than 1000 by some other means than IDCAMS? Is it possible only through changing limit of GDG one by one in IDCAMS?

And if I need to increse the limit of many GDGs in signle go can we do that? Please help.

Thanks.

[enrico-sorichetti]

the GDG max generation number is 255
and You/Your organisation will have to live with it

why would You/Your organisation use a different system utility for the task

a single IDCAMS step can contain as many commands as You want/need

[William Collins]

I think the latest z/OS has new limits.

[enrico-sorichetti]

I think the latest z/OS has new limits.

amending my previous reply and quoting the manual

Using the Generation Data Group enhancements:
Extended format for generation data groups (GDGs):
z/OS V2R2 introduces a new extended format for generation data groups (GDGs). Extended format GDGs can contain up to 999 generation data sets (GDSes). The previous GDS limit was 255 GDSes per GDG. New GDGs can be defined with this new extended format. For existing GDGs, the previous GDS limit still applies.

To support this enhancement, the IDCAMS DEFINE GDG command includes a new optional parameter (EXTENDED) that you can specify to enable a new GDG to contain up to 999 GDSes. If you do not specify that parameter, the default value (NOEXTENDED) takes effect, setting a limit of 255 GDSes for the GDG.

A new GDGEXTENDED parmlib variable lets you specify whether to allow the EXTENDED value to be used on DEFINE of a GDG. If GDGEXTENDED(NO) (the default) is specified, then the DEFINE of a GDG with the EXTENDED parameter is not allowed. If GDGEXTENDED(YES) is specified, then the DEFINE of a GDG with the EXTENDED parameter is allowed. For more information, see the description of IGGCATxx in z/OS MVS Initialization and Tuning Reference.

The LIMIT parameter on the IDCAMS DEFINE GDG command is changed to accept a maximum value of 999 for extended GDGs. The previous maximum LIMIT value of 255 still applies to GDGs which are not defined as EXTENDED.

For extended GDGs, the IDCAMS ALTER LIMIT command is also enhanced to let you set a new GDS limit of up to 999 for the GDG. The z/OS Generic Tracking Facility has also been used to help determine if any calls to Catalog Management are only requesting the classic GDG limit, and not the extended GDG limit.

read and meditate the above snippet from the manual ...
You will have to live with the limits imposed by dfsms
and my question on the why not IDCAMS is still valid

[Sonam Choudhary]

why would You/Your organisation use a different system utility for the task

Thanks enrico-sorichetti. It was to learn different ways of doing same thing. I have noticed some of the examples making use of IKJEFT01 JCL too but looks like ti calls IDCAMS only.

[Sonam Choudhary]

I think the latest z/OS has new limits.

Thanks William.

[Robert Sample]

I have noticed some of the examples making use of IKJEFT01 JCL too but looks like ti calls IDCAMS only.

Changing the number of generations is a catalog function, so why would ANYBODY use anything but IDCAMS to do it? Whether the IDCAMS is invoked through TSO or batch doesn't make a difference -- IDCAMS is used to work with catalogs.

[Sonam Choudhary]

Thanks. After some search I could perhaps understand that whether we use IDCAMS directly or use it using IKJEFT01, it's the same thing. Is not it?

[Robert Sample]

It is the same IDCAMS no matter how you invoke it -- period.