Re: Suggestions on Speeding up a program

Dave,

That's not really an invalid approach....

In fact, once you've gone through the exercises above one time (assuming
you do so completely up to and including rewriting the jobs so they
are efficient as possible) then the next time you need things done faster,
new hardware is about your only recourse.

One can easily spend a couple weeks on tuning...more if you're
not experienced. Only you can decide if it is cost effective.

Charles


On Sat, Jan 5, 2013 at 12:23 PM, Dave <dfx1@xxxxxxxxxxxxxx> wrote:

Noone has suggested my company's approach to the problem, when we found
that the nights were becoming too short for our batch programs to finish in
time, before the users arrived in the mornings! Buy a new machine!
Of course this technique has now been dropped after 2 new machines as it
only works for a while and is very expensive! How I would have loved to
have been able to implement the techniques outlined in this thread.

2013/1/5 Charles Wilt <charles.wilt@xxxxxxxxx>

I assume these are batch programs?

Question: Are the files being written to journaled? If so, are you using
commitment control? If not, that is a _HUGE_ hit. Unless you have the

HA

Journal Performance, 5722-ss1 option 42, installed and being used which
allows for journal caching w/o commitment control. It was previously a
PPRQ.
Here's some good info: http://www.quser.org/Docs/JournalCaching.pdf

Here's some old but still valid info, "Optimizing Batch Performance" by
Rick Turner

http://www-01.ibm.com/support/docview.wss?uid=nas1e907e76673a614dd86256a290054f546

Here's the key take away, unless your CPU usage is at 100% during the
program run, your program is waiting (probably for disk I/O)...remove as
much wait as you can and if you're still not at 100%, break the job into

as

many concurrent processes as needed to drive the CPU usage to 100%.

HTH,
Charles




On Thu, Jan 3, 2013 at 9:43 AM, RPGLIST <rpglist@xxxxxxxxxxx> wrote:

I'm looking for any and all suggestions on possible ways to speed up

some

programs.

The typical ones that come to mind are:

1. avoiding open and closes on files
2. Not setting LR when calling a program or procedure multiple times
3. using Data structures for block reads and writes

Any other suggestions?

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