How to Initialize the VSAM file using JCL

vasanthkumarhb · Posted: Fri Apr 25, 2008 11:40 am

Hi,

there is a cobol program which writes and re-writes the VSAM dataset, the content of VSAM data set is used to generate a REPORT.

The VSAM data set is an empty dataset before the data written to it, the file opened in I/O mode because VSAM processing involves both write and rewrite.

To do this process we have a JCL which DELETES the cluster and CREATES the cluster every time the JCL is sbmitted, but still when we check the VSAM dataset was not intialised.

We did write another small program and opened the VSAM in OUTPUT mode and closed the VSAM, we keep this program execution in one STEP of JCL before the actual progam, But still the VSAM data set is not intialised.

Is there is any way, so that we can intialise the empty VSAM dataset thru JCL

Thanks in Advance.

Arun Raj · Posted: Fri Apr 25, 2008 12:32 pm

Vasanth,

What do you mean by both write and rewrite.? If you want to reuse the cluster define it with REUSE option instead of deleting it and creating it again.

Thanks,
Arun

expat · Posted: Fri Apr 25, 2008 12:36 pm

To initialise the VSAM cluster, you usually write a record to it.

It is common practice, and common sense if you ask me, that every VSAM KSDS has a low and high values record inserted as default.

enrico-sorichetti · Posted: Fri Apr 25, 2008 12:36 pm

to have a vsam dataset initialized open and close is not enough...
search the net for something like "VSAM INITIALIZATION" You will find many useful hits

www.cbttape.org file183 for example

mymains · New User Joined: 24 Apr 2008 Posts: 5 Location: Banglore

Hi Vasanth,
i think by using a GDG we can easily solve this problem being u creating a report it is quite useful compared to use simple vsam files\
thnkz
Mymains

jaspal · New User Joined: 22 May 2007 Posts: 68 Location: mumbai

Hi,

1). To initialize the VSAM ,you can open it once in output mode and close it in program during initializaton, it could solve your problem.
after that again open it in I/o mode.

2) write a step in jcl whic delete defines VSAM and REPRO some records from a flat file Say GDG version.
this step should be executed before program uses VSAm.

Regards,
Jaspal @ 9833814470

Ajay Baghel · Posted: Fri Apr 25, 2008 8:27 pm

Refer to the below link:
ibmmainframes.com/about6008.html

Bill O'Boyle · Posted: Fri Apr 25, 2008 9:19 pm

If you have DITTO, you can initialize a newly created record with low-values, via -