Creating a dataset

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diwz
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Post by diwz » Wed Feb 27, 2013 4:14 pm

Yes Anuj, It has created a VTOC entry but doesnot uses spaces

Code: Select all

VTOC:   1800 Tracks (  11 %Used)   80398 Free DSCB'S           9354 Data sets 
VOL:  150255 Tracks (  81 %Used)      15 Tracks/cylinder          0 ALT Tracks
FREE:   1738 Cyls (MAX= 1012)      29054 Trks (MAX= 15180)      795 Free Xtnts
 --------- D A T A S E T   N A M E ---------- Org   Trks %Used XTS=  Status   
 A345677.CREATE.DATASET.ZERO.SPACE            ??       0    0     0   
I understood from your reply that these kind of dataset has minimal usage in jobs. The only place that I am thinking of this dataset will be of use is when we need to check for file existence criteria in JCL to execute desired step.

William Collins
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Post by William Collins » Wed Feb 27, 2013 4:24 pm

That's one purpose.

Can also be used with IEFBR14, DISP=(MOD,DELETE), the technique to delete a dataset if it exists, otherwise to create and delete it at the same time, saving a JCL error if instead using DISP=(OLD,DELETE).

Once you have your dataset with no space, you can actually use it in JCL by specifying a different SPACE parameter in the step outputting to the file. This will temporarily override what it has been catalogued with, but will not change the catalogued value.

Anuj Dhawan
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Post by Anuj Dhawan » Thu Feb 28, 2013 7:52 pm

I'm not sure what do you mean by "minimal usage" here:
these kind of dataset has minimal usage in jobs
On the other hand - as William said, what you've mentioned is one of thes examples , the other is 'GDG DSCB model', which I've mentioned in earlier post too.
Regards,
Anuj

diwz
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Post by diwz » Fri Mar 01, 2013 1:08 pm

I was trying to think of what is the need of this type of datasets(Space as zero) and how much we can make use of it in developers world.

diwz
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Post by diwz » Fri Mar 01, 2013 1:11 pm

[quote]
On the other hand - as William said, what you've mentioned is one of thes examples , the other is 'GDG DSCB model', which I've mentioned in earlier post too.[/quote]

I am not familiar about GDG DSCB mobel. Couldn't understand this example alone. Can you brief me. By the time you reply, I will try to get some information for myself on GDG DSCB.

Anuj Dhawan
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Post by Anuj Dhawan » Fri Mar 01, 2013 3:39 pm

DSCB is Data Set Control Block. A control block in the VTOC that describes data set characteristics. However, if your site is SMS managed (and which site is not these days) this is not needed these days.
Regards,
Anuj

diwz
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Post by diwz » Sat Mar 02, 2013 10:48 am

In my site, while creating GDG version I use to code without giving DSCB in DCB as it is managed by SMS.

I observed that some of the jobs are running in production has DSCB model specified in DCB parameter for GDG versions. When I checked the attributes of those versions in production, they are in SMS. Does this means that SMS will ignore DSCB?. I was checking the manuals from IBM site. Couldnot get my way to understand.

Anuj Dhawan
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Post by Anuj Dhawan » Sat Mar 02, 2013 9:33 pm

Check here: http://publibz.boulder.ibm.com/cgi-bin/ ... 0122112221

And if you're more interested about GDGs, spend some time here: http://publibz.boulder.ibm.com/cgi-bin/ ... 0122112221
Regards,
Anuj

Anuj Dhawan
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Post by Anuj Dhawan » Sat Mar 02, 2013 9:35 pm

An after thought - we're getting in to too many directions and the original question is lost somewhere. Suggest if you've more questions which are not interrelated, please start a new thread.
Regards,
Anuj

diwz
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Post by diwz » Sat Mar 02, 2013 10:08 pm

Yes Anuj. Next if there is any questions I will start a new thread.

diwz
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Post by diwz » Sat Mar 02, 2013 10:27 pm

[quote="Anuj Dhawan"]
Check here: http://publibz.boulder.ibm.com/cgi-bin/ ... 0122112221

And if you're more interested about GDGs, spend some time here: http://publibz.boulder.ibm.com/cgi-bin/ ... 0122112221
[/quote]

This link is useful. Thanks Anuj.

Anuj Dhawan
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Post by Anuj Dhawan » Tue Mar 05, 2013 5:15 pm

You're welcome. :)
Regards,
Anuj

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