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Magesh_J · Intermediate Joined: 21 Jun 2014 Posts: 259 Topics: 54

Hi,

We have number of jobs reading a VSAM file sequentially, Randomly, Dynamically at a time.

In this there are some non critical jobs, which can be executed later.

My question is, Multiple jobs reading a file in browse mode at a time, will affect the performance or elapsed time.

Please advise.

Thanks
Magesh

Terry_Heinze · Posted: Tue May 12, 2015 9:15 am Post subject:

Probably both, but with todays CPU and I/O speeds, it will probably not be very noticeable unless you have the VSAM file defined in a very unorthodox way.
_________________
....Terry

William Collins · Supermod Joined: 03 Jun 2012 Posts: 437 Topics: 0

In general:

If you have 10 jobs executed in sequence, vs 10 jobs all executed at the same time, the total elapsed time for the process (that means from when the first starts to when the last finishes) will be reduced.

The total elapsed time of the individual jobs may be different (more).

I don't think you'd see much variance in the CPU time.

In specific:

It may depend on how your VSAM file is defined for use.

Try it.

Magesh_J · Intermediate Joined: 21 Jun 2014 Posts: 259 Topics: 54

Thanks William and Terry for the kind response.

The file is defined with SHR(2 3) SPEED RUS -

During the batch hours online will down, so no updates on this file.

Regards,
Magesh