Difference in creating a DataSet

muthukrishnan · New User Joined: 12 Sep 2003 Posts: 4

What is the difference between coding
//sysin dd xxxx
and
// dd ddname=sysin

is there any specific reasons for coding like this??
and if yes what is the criteria?

and when we use array and when we use table??
and how will you define a dataset?

Pls anyone clear me this pls!!!!!!!!!!!

mdtendulkar · Active User Joined: 29 Jul 2003 Posts: 237 Location: USA

Hello muthukrishnan,

what is your expertise in mainframes??

also can you eloborate your queries??

Regards

Mayuresh Tendulkar

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

Hi M,

DDNAM= is usually used to get around the restriction of using instream data in PROCs. You can use it in other ways, but this is the most common.

Consider:

You have a proc that contains one or more steps that require instream data. Let's say the proc is PROC1 and it has 2 steps. The pgm in STEP1 uses an ACCEPT stmt to "read" instream data. The pgm in STEP2 uses an FD and READ to read instream data.

In the proc for STEP1 you code:

//SYSIN DD DDNAME=S1CARDS

For STEP2 you code:

//CARDFILE DD DDNAME=S2CARDS

In the JOB JCL you code:

//MYJOB JOB ....
// EXEC PROC1,...
//STEP1.S1CARDS DD *
your cards go here
//STEP2.S2CARDS DD *
your cards go here

If you don't include the O'ride stmts S1/S2CARDS they default to DUMMY.

Regards, Jack.

muthukrishnan · New User Joined: 12 Sep 2003 Posts: 4

Hi jack

thankyou for your explanation on dummy and ddname.
but i wish to ask mauresh that for him to answer the quesstion he doesnot want my expertise!!!!

if you are not interested u can leave it o others ok
beware that all of them are not experts at starting itself ok!!!!!!

mdtendulkar · Active User Joined: 29 Jul 2003 Posts: 237 Location: USA

Hello muthukrishnan,

I think you are new to the discussion forums on the web,

There were 2 reasons why i asked you these questions:

1) The question I asked you was just out of the suspicion as the questions you asked were of very basic level.

Nowadays, the proxy users from other forums log on to the sites and try to create a difficult situation to the forum users by asking very basic level questions (which can be found in any manual)

If anybody who is genuine will definately get an answer to the questions posted.

2) The answers given would depend on your level of experience. Little experience would dictate detailed answers, lots of experience dictates very brief answers

There was no personal intention in asking the questions.
No hard feelings please.

Hope I made myself clear, feel free to ask anything.

Regards

Mayuresh Tendulkar

muthukrishnan · New User Joined: 12 Sep 2003 Posts: 4

hi
ok will ask only the difficult problems
muthu

sandip_datta · Posted: Thu Dec 04, 2003 2:24 pm

Hi M,

Please don't behave like childish...No one is restricting you to post simple questions. Experts have also started from simple ideas.

You have aske how to define a dataset ?
It can be answered in a lot of way - both simple and in harder way.
If you are a novice probably Mayuresh will tell you to use ISPF option 3.2 to allocate a dataset. If you are a little bit of experienced then probably you will get an answer regarding allocating datasets using JCLs. A little bit more experience will give you the option of allocating through Cobol programs also...and many other harder way.
Here your requirement is not clear and so Mayuresy had asked your ability to grab the answer.

regards,
Sandip.

mf_user · New User Joined: 05 Jan 2006 Posts: 47

Hi Jack,

The piece of infomation you've provided here is really new to me. I have leisure time now so, started exploring the site to acquire knowledge.

Nice stuff.

Thanks.