Create a new GDG generation in step 1 of my jcl

dkalyan_c · New User Joined: 06 Apr 2006 Posts: 17

hello !!

i want to create a new GDG generation in step 1 of my jcl
this generation should be input to step2 and step 2 creates a second generation.This second generation is input step3 and step3 creates a third generation.

now, how do i refer the generations in my JCL

STEP1 - generation(+1)
STEP2 - INPUT -generation(+1)
OUTPUT - generation(+2)

STEP3 - INPUT -generation(+2)
OUTPUT - generation(+3)

is the above one correct? or i should always refer the current generation as generation(0)?

dick scherrer · Posted: Sun Feb 14, 2010 11:33 am

Hello,

Suggest you reconsider the process. . . What reason is there to create 3 new generations of the same fle in one job?

There is probably no need to create 3 new generations in a job. If you create some intermediate files and then a new +1 at the end, you will have everything you need.

Unless there is something i misunderstand. . .

naveensrimf · New User Joined: 04 Oct 2005 Posts: 34

Above one is correct.

Please see the example for you.
// Step1 exec=ABC1
//File1 dd DSN=XYZ.ABC.123(+1),Disp=shr
//File 2 dd DSN=XYZ.ABC.123(+2),Disp=(new,catlg,delete),
.
.
// Step2 exec=ABC2
//File2 dd DSN=XYZ.ABC.123(+1),Disp=shr
//File 3 dd DSN=XYZ.ABC.123(+2),Disp=(new,catlg,delete),
.
.
//Step3exec=ABC3
//File3 dd DSN=XYZ.ABC.123(+1),Disp=shr
//File4 dd DSN=XYZ.ABC.123(+2),Disp=(new,catlg,delete),

dick scherrer · Posted: Mon Feb 15, 2010 6:45 am

Hello,

Robert Sample · Posted: Mon Feb 15, 2010 7:57 am

Generations are not cataloged until the end of the job; if you build a new generation it is (+1) throughout the entire job. If you build another new generation, it is (+2) throughout the entire job. and so forth.

However, as Dick said, you will have problems with such an approach. One thing that is pretty much guaranteed with production jobs is that they are going to have problems sooner or later. Having someone trying to figure out how to do a restart at 3 AM of a job that creates three new generations will be challenging, at the least.

prem_ibm · New User Joined: 15 Sep 2007 Posts: 31 Location: Chennai

Hi All,

Please clarify below :--

Whether its Depend on JES....?

1) Generation will be Cataloged after succesfull execution of Job....when JOB ENTRY SYSTEM (JES2)....(agree) i have tested for JES2,whether it will be same for JES3.

Thanks

Prem...

dick scherrer · Posted: Mon Feb 15, 2010 11:23 am

Hello,

UmeySan · Posted: Mon Feb 15, 2010 4:05 pm

Hi Dick !

JES2:
Generation will be Cataloged after succesfull execution of Job

JES3:
Generation will be Cataloged after succesfull execution of Step

Robert Sample · Posted: Mon Feb 15, 2010 5:54 pm

There's no difference between JES2 and JES3 as to how relative generation references work. From the JCL User's Guide Appendix A:

gcicchet · Posted: Tue Feb 16, 2010 3:44 am

Hi,

I have to disagree with this

Robert Sample · Posted: Tue Feb 16, 2010 3:55 am

Note that it does not matter when the generation is cataloged, the first reference to a relative generation number fixes the sequence for the entire job. The manual has an example where the (-1) generation is used in step 1 and that refers to absolute generation 7. Step 2 deletes all generations and step 3 allocates a (+1) entry. Since the relative numbers were fixed at the time of first reference, the absolute generation cataloged in step 3 is G0009V00, even though generations up through G0008V00 were deleted in step 2.

UmeySan · Posted: Tue Feb 16, 2010 2:46 pm

Morning Robert !

I only talked about the time when cataloging come true.
And sorry, when something changed within the last 20 years.

But in those days, that was the crucial difference in this surroundings.

Robert Sample · Posted: Tue Feb 16, 2010 4:38 pm

UmeySan, the manual is not clear about precisely when a generation is cataloged -- and it appears that SMS managed GDGs are handled differently from non-SMS GDGs -- but the handling of relative generations hasn't changed in a long time.