Re: Handling Files in a Subproceedure

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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