Delete all the records in a VSAM file in Cobol pgm

annujp · Posted: Thu Oct 11, 2007 12:40 am

Hi

My requirement is;for a particular run of the program (characterised by a specific month) i need a vsam file that is used in the program to be flushed of all the data. The file is a yearly file so at the start of the year i need to start with a fresh file. I want to do this in the cobol pgm.

I used the following code
IF MONTH = '02'
OPEN OUTPUT VSAM-FILE
CLOSE VSAM-FILE
END-IF

The logic behind writing this is when you open a file in output mode and close it immediately, all the records in the file are deleted.
But here i get a VSAM Status code of '37' for the OPEN Output(wrong mode of opening) and a status code '42' for the CLOSE (closing a file that is not open). My JCL has a DISP=SHR for this VSAM file.

Is there anyway i can do this in a cobol program?
I need to delete all the records in a vsam file. Also what should be the disp parameter i should give in my JCL?

Anitha

dick scherrer · Posted: Thu Oct 11, 2007 1:08 am

Hello,

Rather than COBOL, you might just do an IDCAMS DELETE/DEFINE as the first job of a new year's processing.

You may need to read the records in order to delete them in a program (i'm not certain on this one - never tried to do it), but delete/define works rather quickly an dwe use it frequently.

annujp · Posted: Thu Oct 11, 2007 2:50 am

Hi
My issue is that i want to use the same JCL throughout the year. If i were to do an IDCAMS repro for the new year processing, then i would have to use a separate JCL for that, right?
Is there any way to check for the current month (or date) in a JCL and execute a step accordingly?

I checked with reading a VSAM opened in I-O mode and then closing it, it does not delete the records in the file.

Thanks
Anitha

dick scherrer · Posted: Thu Oct 11, 2007 3:00 am

Hello,

You could do it all in one jcl - add a step that runs first that sets a contition code for the first run of the year and test the condition code in the idcams step and then continue with the run.

William Thompson · Posted: Thu Oct 11, 2007 3:06 am

Programmaticly, a second select/fd/DD could be used, couldn't it? The VSAM file might need a REUSE parm....You are closer to a manual than I am, look it up....

annujp · Posted: Thu Oct 11, 2007 3:09 am

Yeah i am trying to do that. But the step that will run just once a year has to be determined by the date(say month = 01). How do i get the step to run when the month = 01?
I searched the forums and came up with this
http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/IEA1E241/2.2.2
I tried using it in my JCL like this

CICS Guy · Posted: Thu Oct 11, 2007 3:19 am

Flying a bit blind, but either some sort of JCL "optional" for the output DD or a additional step prior that opens the file for output on the selected date....you can't shr the output DD, can you?
Then again, there is dynamic allocation from the cobol batch program on the needed date.....

dick scherrer · Posted: Thu Oct 11, 2007 3:57 am

Hello,

annujp · Posted: Thu Oct 11, 2007 4:19 am

Thanks a lot for the prompt replies.
So the best approach would be to write a small cobol program that will check for the current date. If the current date satisfies the condition for flushing the data, i will set a specific return code.
In the JCL, i will execute the IDCAMS step to repro a blank file only if it is the desired return code.

To do this i use the following piece of code,right?

CICS Guy · Posted: Thu Oct 11, 2007 4:22 am

Sounds like a plan...
Good thinking....

dick scherrer · Posted: Thu Oct 11, 2007 6:07 am

Hello,

expat · Posted: Sat Oct 13, 2007 5:28 pm

So why do you want to waste resource on writing a program that will probably use much more resource deleting records individually than by using the very utility IDCAMS to do the same thing in a fraction of the time.

If your shop uses a scheduling package you can set up for the IDCAMS step to be included automatically on the date that you want it to be included in.

Dare I ask who's idea it was to do this programatically rather than easily ?

annujp · Posted: Sun Oct 14, 2007 5:54 am

dick scherrer · Posted: Sun Oct 14, 2007 7:01 am

Hello Anitha,

Just a reminder - it would be good to backup the file

expat · Posted: Sun Oct 14, 2007 10:46 pm

So how long does it take to schedule one job ? 10 minutes max ?

How long to code and test the program. How long will it take to delete perhaps millions of records ? IDCAMS will take seconds with no development or maintenance overheads. What if the requirement changes ? then it's back to the program again.

All I'm asking is why you do not want to follow the easiest option for efficiency ?

dick scherrer · Posted: Sun Oct 14, 2007 10:57 pm

Hi Expat,

annujp · Posted: Mon Oct 15, 2007 3:09 am

Yeah thats wat i plan to do.
I dont delete any records in the cobol program. All the program does is to set the return code after checking for the month part of the current date. Based on the return code the steps to delete and define the VSAM using IDCAMS is run.

Dick, as per your suggestion i will be doing a backup of the VSAM file before the delete and define.

Thanks
Anitha

dick scherrer · Posted: Mon Oct 15, 2007 4:12 am

You're welcome

We're here if there are questions.