Re: Handling Files in a Subproceedure

[Mike <koldark@xxxxxxxxx>]

I might be calling this in a loop; for sure every displayed record. I have
the activation group as *CALLER. So all I have to do is check to see if the
file is open, and if it is to just continue processing?

On 7/19/07, Scott Klement <rpg400-l@xxxxxxxxxxxxxxxx> wrote:
> Opening a file is a very expensive operation. (One of the most expensive
> ones that I use on a regular basis, in fact.)
>
> So I guess the real question is:  How often do you expect your procedure
> to be called?  Are there programs (or can you envision a scenario) that
> need to call your procedure over and over in a loop?  If so, I'd say
> that opening and closing the file each time is a bad idea.  It's suicide
> to performance.
>
> In my experience, the most common (and probably best) practice is to
> open the file once, and then just leave it open until the activation
> group or job ends.    Some people provide additional routines to allow
> the caller to explicitly re-open or re-close the files without having to
> end the activation group.
>
> Are there circumstances where it makes sense to open the file on every
> call to the procedure?  Absolutely.  It really depends on what you're
> doing!   But, in 95% of the cases, you want to leave the file to improve
> the performance of subsequent calls.
>
>
> Mike wrote:
> > Maybe I worded it wrong. "Best Practice" maybe?
> >
> > It looks like others do the same thing open and close the file on every
> > call. I didn't know if I could or should keep the file open while the
> main
> > program is running. This is in a module by the way.
> >
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