create files dynamically

enrico-sorichetti · Posted: Tue Dec 21, 2010 7:03 pm

NO!
I just run a simple test and was able to allocate 1000 datasets

IDCAMS ALLOC invokes under the covers TSO ALLOC ( stated in the manual and confirmed by the IKJ**** messages)

if the FI/DDNAME parameter is not specified one will be build according to the dynamic ddnames build rules

so in this case RULE 1 applies ==> too many allocated ddnames

but if as I did You use a construct like

enrico-sorichetti · Posted: Tue Dec 21, 2010 7:52 pm

here is the jcl of a successful test ( ALLOCATE,REPRO,PRINT)

mlp · New User Joined: 23 Sep 2005 Posts: 91

Only difference in your and mine ALLOC statement is that, I did not use REUSE parameter. I used that parameter but nothing happened. The issue still persists.

Also you did not used the DYNAMNBR option. Still you were able to execute 1000 allocations. I also tried with JCL without DYNAMNBR option. But it failed on 3rd instance of allocation.

dick scherrer · Posted: Wed Dec 22, 2010 10:54 am

Hello,

Suggest you speak with your system support people and learn how your limits have been defined. . .

I still have no idea why someone believes it is acceptable to allocate 3000+ datasets for one task. . .

If you explain why this is being done, someone may have an alternative suggestion.

mlp · New User Joined: 23 Sep 2005 Posts: 91

For a certain assignment I need to create datasets in this volume. Also the names of the datasets are going to be decided run time with certain variable values. This proces is going to be repeated on weekly/monthly basis. Also some of the datasets need to be prefilled with some content.

I have written a COBOL prog to create a control card which is then fed to IDCAMS step which is actually creating and filling the datasets with soem content.

I want to do this process in one shot, becuase there might be the case I need to allocate more than 3000 datasets. At that point of time I dont want run my job again and again so that all allocations are done.

Please suggest if there is any good solution for this.

Dsingh29 · Active User Joined: 16 Dec 2008 Posts: 132 Location: IBM

hi,

have you tried using CALL "SETENV". I think dynamic file allocation can be done thru this method also in cobol programmes.

Just posted this, as it might of some interest/help to you.

enrico-sorichetti · Posted: Wed Dec 22, 2010 11:54 am

the major difference is that I used the FI(OU) parameter in order not to hit the DDNAME limit!

the REUSE is forced by the FI(OU) .

I gave You a tested solution!
why don' t You try to run MY jcl to see what happens

the trick is the FI parameter

without it I also got the error after a few datasets.

mlp · New User Joined: 23 Sep 2005 Posts: 91

The trick worked !!

I did not get any error with FI parameter. Also I did not specify DYNAMNBR option in my jcl step.

Thanks a lot Enrico...

mlp · New User Joined: 23 Sep 2005 Posts: 91

I have came to know that one program/ programatic interface BPXWDYN can actually do the dynamic allocations and uses TSO like commands. This program is callable thru COBOL programs. BPXWDYN supports data set allocation, unallocation, concatenation, the retrieval of certain allocation information, and the addition and deletion of output descriptors. Below is description what I found on IBM site.

The syntax for allocation is quite similar to that of TSO for the TSO ALLOCATE and FREE commands. It should be possible to provide parameters to BPXWDYN that would be acceptable as a TSO ALLOCATE or FREE command. However, there are keys supported by TSO ALLOCATE that are not currently supported by BPXWDYN. There are also some keys that can be used with BPXWDYN which are not compatible with TSO.