RE: Trigger Question

Hi Scott,

A minor point about this part

"If you copy a file with 10000 records onto the file with the trigger,
> you'll submit 10000 jobs, which might cause a big slowdown on the system
> as all 10000 are launched at once."

They are certainly all submitted at once, but the activity level for the
jobq they are submitted to will determine whether they are all "launched" at
once.  If it's a single-thread jobq, they'd run 1 at a time.

Not that I'd want to see 10,000 jobs suddenly appear on a jobq <grin>...

Peter Dow
Dow Software Services, Inc.
www.dowsoftware.com
909 793-9050 voice
909 793-4480 fax

> -----Original Message-----
> From: midrange-l-bounces@xxxxxxxxxxxx
> [mailto:midrange-l-bounces@xxxxxxxxxxxx]On Behalf Of Scott Klement
> Sent: Monday, December 19, 2005 9:30 AM
> To: Midrange Systems Technical Discussion
> Subject: Re: Trigger Question
>
>
>
> > A discussion of Triggers the other day got a little heated when
> one member
> > of the discussion said that IBM recommends that Trigger
> programs should not
> > be designed to SBMJOB jobs but rather should do all of the
> processing within
> > the bounds of the trigger program itself.
>
> A trigger is fired every time the "event" occurs.  Let's say that every
> time a record is added to a file, you want to submit a job to do some
> processing.  This means:
>
> a) Every time an application writes a record, a new job will be created.
>
> b) If a program writes 10 records in rapid succession, 10 jobs will be
> submitted.  You'd better be careful to make sure those jobs can run
> concurrently and not conflict with one another.
>
> c) If you copy a file with 10000 records onto the file with the trigger,
> you'll submit 10000 jobs, which might cause a big slowdown on the system
> as all 10000 are launched at once.
>
>
> Even worse is when the event is on an update or delete, because you may
> have batch processes updating or deleting thousands and thousands of
> records, causing thousands and thousands of jobs to be submitted.
>
> But, having said that... not everyone does that.  Sometimes people have
> files that aren't added to, updated or deleted rapidly.  Maybe in your
> business you have a file where one record is added one time per day.  In
> that situation, having a job submitted isn't a problem at all.
>
> And that's the point I really want to make...   it all depends on your
> business and how it works.  YOU have to decide what's acceptable and
> what's not.
>
> I personally think that data queues (or a similar means) are a
> much better
> idea than submitting a new job for every record, since they allow you to
> control how many jobs get submitted at any one point, and therefore keep
> things running smoothly.
>
> Doing things within the bounds of the trigger might be good, too...  it
> really depends on what you have to do!
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