Concatenating Datasets



Concatenating Datasets

Postby sinmani » Mon Oct 08, 2012 5:10 pm

8. Indicate the correct answers. (2 answers)

A concatenation of datasets...
a. Can be used for input, to use both DD entries describing sequential datasets and DD entries describing partitioned datasets in any order.
b. Can be used to write multiple output datasets.
c. Can contain a dummy data set in the input, which will indicate the end of the input.
d. Stored on different device types, cannot be used for input.
-----------------------------------------
As long as you think you are a student, you are doing well.
The day you consider yourself as the master of the game..........well
sinmani
 
Posts: 93
Joined: Thu Mar 22, 2012 10:02 am
Has thanked: 14 times
Been thanked: 0 time

Re: Concatenating Datasets

 

Re: Concatenating Datasets

Postby NicC » Mon Oct 08, 2012 7:27 pm

When you post interview questions you should also post the answers you made. And your answers were?
The problem I have is that people can explain things quickly but I can only comprehend slowly.
Regards
Nic
NicC
Global moderator
 
Posts: 2690
Joined: Sun Jul 04, 2010 12:13 am
Location: Pushing up the daisys (almost)
Has thanked: 4 times
Been thanked: 105 times

Re: Concatenating Datasets

Postby sinmani » Wed Oct 10, 2012 1:24 pm

Hi NicC,

my answers are higlisghted in RED.

A concatenation of datasets...
a. Can be used for input, to use both DD entries describing sequential datasets and DD entries describing partitioned datasets in any order.
b. Can be used to write multiple output datasets.


c. Can contain a dummy data set in the input, which will indicate the end of the input.
d. Stored on different device types, cannot be used for input.
-----------------------------------------
As long as you think you are a student, you are doing well.
The day you consider yourself as the master of the game..........well
sinmani
 
Posts: 93
Joined: Thu Mar 22, 2012 10:02 am
Has thanked: 14 times
Been thanked: 0 time

PIC Clause

Postby sinmani » Wed Oct 10, 2012 1:55 pm

2. The following combination of edit characters can appear in the same PIC clause EXCEPT,
a. -$*
b. $CR
c. $Z9
d. -$CR
e. -$Z9

My answer marked in RED
-----------------------------------------
As long as you think you are a student, you are doing well.
The day you consider yourself as the master of the game..........well
sinmani
 
Posts: 93
Joined: Thu Mar 22, 2012 10:02 am
Has thanked: 14 times
Been thanked: 0 time

Re: Concatenating Datasets

Postby sinmani » Wed Oct 10, 2012 1:56 pm

4. Which of the following statement is incorrect?

a. Subscripting enables us to write a more compact code in the procedure division.
b. Subscripting enables us to refer to any element of a table by the same data name with the facility of identifying the particular element through the values of subscript.
c. Subscripting reduces the number of entries to be included in the data division.
d. Subscripting enables us to use loops in the procedure division.
-----------------------------------------
As long as you think you are a student, you are doing well.
The day you consider yourself as the master of the game..........well
sinmani
 
Posts: 93
Joined: Thu Mar 22, 2012 10:02 am
Has thanked: 14 times
Been thanked: 0 time

Re: Concatenating Datasets

Postby NicC » Wed Oct 10, 2012 2:29 pm

Sinmani,

I suggest you go and review the JCL manuals - Reference and User Guide and the COBOL language reference. I think ALL your answers are wrong. Notice that some questiuons ask for CORRECT and some for INCORRECT.
The problem I have is that people can explain things quickly but I can only comprehend slowly.
Regards
Nic
NicC
Global moderator
 
Posts: 2690
Joined: Sun Jul 04, 2010 12:13 am
Location: Pushing up the daisys (almost)
Has thanked: 4 times
Been thanked: 105 times

Need Help

Postby sinmani » Thu Oct 11, 2012 1:32 pm

I do read thru IBM help and various forums amd educational websites.

Since I am unable to get the right answers I have posted them here.

looking for help from members.
-----------------------------------------
As long as you think you are a student, you are doing well.
The day you consider yourself as the master of the game..........well
sinmani
 
Posts: 93
Joined: Thu Mar 22, 2012 10:02 am
Has thanked: 14 times
Been thanked: 0 time

Re: Concatenating Datasets

Postby BillyBoyo » Thu Oct 11, 2012 1:45 pm

As is common, the questions themselves are poorly-formed. I'd not like to give two "correct" answers for the first.

A concatenation can only be for input datasets. Then from the JCL manual find out restrictions within that (some questions for you: can they be VSAM?; can you mix F and V?; can you mix different blocksizes? What happens if the third of five concatenated datasets is DD DUMMY?)

For the subscripting, just think about it. Remember you are looking for something which is false, rather than something which is a cast-iron necessity relating to subscripting. A Clue: You must define a subscript yourself.

The PIC question is more difficult than it looks, because of the number and variety of editing characters, some of which you may never have used. However, if you look in the Cobol Language Reference you will quickly discover the answer, and by reading around it you may discover why, and then you'll know for next time.

These users thanked the author BillyBoyo for the post:
sinmani (Thu Oct 11, 2012 1:53 pm)
BillyBoyo
Global moderator
 
Posts: 3804
Joined: Tue Jan 25, 2011 12:02 am
Has thanked: 22 times
Been thanked: 264 times

Re: Concatenating Datasets

Postby sinmani » Thu Oct 11, 2012 3:31 pm

BillyBoyo wrote:A concatenation can only be for input datasets.

But here they are saying that we can write multiple output datasets for a set of concatenated datasets.
For example I may read 10 in[put concatenated files and write 5 ( multiple) output files. which should be correct


Then from the JCL manual find out restrictions within that (some questions for you: can they be VSAM?)

VSAMs cannot be concatenated;

can you mix F and V?
Please answert his one??
What I feel is that if we first reformat variable length file into fixed block and then concatenate.


can you mix different blocksizes?

Yes

What happens if the third of five concatenated datasets is DD DUMMY?

Please answer this one :(
.
-----------------------------------------
As long as you think you are a student, you are doing well.
The day you consider yourself as the master of the game..........well
sinmani
 
Posts: 93
Joined: Thu Mar 22, 2012 10:02 am
Has thanked: 14 times
Been thanked: 0 time

Re: Concatenating Datasets

Postby BillyBoyo » Thu Oct 11, 2012 4:03 pm

If you have something in your JCL which you know is an output file, the system doesn't know that from the JCL. You can code a concatenation on that and submit your JCL - but it won't do anything remotely useful for you.

You can, of course, read any input (concatenated or not) and write to multiple output files, but this is not concatenation, it is just multiple files.

Correct, VSAM cannot be concatenated.

You can't mix F and V. Of course you could convert one to the other, but then you'd no longer have a mix anyway.

On the "mix blocksizes" it is a "trick" question in two parts: can you mix different FB datasets?; can you mix different VB datasets, and if so with what restriction?

You can experiment. Get two different FB datatsets and try. Make an enormous record on one VB and a very short record on another and try to process on a concatenation with the short one first (this didn't used to work, maybe it has changed, I haven't checked).

DD DUMMY, and it is in the manual, will give end-of-file when encountered in a concatenation. If you have two datasets, DD DUMMY, then two more datasets on your concatentation, then only the first two datasets will be read.

These users thanked the author BillyBoyo for the post:
sinmani (Thu Oct 11, 2012 4:19 pm)
BillyBoyo
Global moderator
 
Posts: 3804
Joined: Tue Jan 25, 2011 12:02 am
Has thanked: 22 times
Been thanked: 264 times

Next

Return to Interview Questions