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theoldstone · Posted: Tue Jan 13, 2009 11:16 am Post subject: IAM File Type

Hi Folks,

I have an IAM file on the production mainframe system and when I transfer it to the test machine it via connect direct it becomes VSAM.

I'm aware that the IAM file is more efficient file type than VSAM, but I'm interested to find out why it changed ?

And also were could I get useful information on IAM files to allow me to find out how to define a IAM file through JCL.
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Regards,
Brian

RonB · Posted: Tue Jan 13, 2009 5:35 pm Post subject:

IAM is a proprietary access method that automatically intercepts VSAM calls and converts them to IAM calls if the dataset is defined as IAM. It is possible that you do not license IAM for the test machine, therefore the file cannot be allocated as IAM on the testing machine.
Unless you wish to use some of the advanced features of IAM allocations, merely providing the parameter OWNER($IAM) in a normal VSAM DEFINE statement will cause the file to be created as an IAM file, instead ( if, that is, the machine on which the file is being defined is running an IAM license ).
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A computer once beat me at chess, but it was no match for me at kick boxing.

theoldstone · Posted: Wed Jan 14, 2009 3:17 am Post subject:

Thanks for that information. I most check out the IAM licence on the test box.

The reason behind my testing is that I need to complete a delete and redefine of the produciton file as its attributes need to change, so I'm trying to make sure its redefined as a IAM file and not a VSAM file.
_________________
Regards,
Brian

theoldstone · Posted: Thu Jan 15, 2009 11:48 am Post subject:

Just to say thank you to Ron !

The owner parameter has worked ok. Very Happy

_________________
Regards,
Brian