Re: Occurs Depending Memory Use

HeyBub wrote:

Kevin Solomon wrote:

Thanks to everyone for your replies.

If I understand what Richard's saying, the only real savings of using
an OCCURS DEPENDING ON clause is in overall performance and not in
the amount of memory allocated.  Of course, this means that I do not
have a solution to the actual problem we were trying to solve with
this construct.

The problem is simply that we have a program that for the next
processing year will require seven or eight tables of between 1 and
10,000 occurrences and we're endevouring to find a way to use only
the amount of memory that is actually necessary for each iteration.
As I stated in my original post, the program executes online in CICS.
(If the program was executing in batch, we'd not have a need to
optimize memory.)  There is a potential for several hundred
concurrent users of the program.  If one iteration of the program
requires 4MB-6MB of memory and there are several hundred concurrent
users and several thousands of other programs competing for
resources, you can see why we'd rather not take 4MB of memory for
each instance of the program when it is only the maximum that would
be required.

The number of occurences that are required for each iteration is
variable upon a count of transactions returned from a DB call.  Does
anyone have any ideas on how memory use might be optimized?



You're just kicking the can down the road.

Use disk files. Where possible, the OS will keep all the files in memory, so you'd be letting the OS optimize your memory usage. If you ultimately suffer a performance hit, get faster hardware.

Good advice IMHO - if you're running on Big Blue's big iron you can specify UNIT=SYSVIO (I think it's the UNIT parm, "VIO" = virtual I/O) and the OS will place your work files on page datasets, which will maximise your performance.
.

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