Re: Qualified vs Unqualified calls (Was: Database server jobs and SQL tuning)

[Bob Larkin <blarkin@xxxxxx>]

John,
Great work. Now for some real fun, have your program open a file, read a 
record, then
return. After that, try leaving LR *OFF.
The only reason I mention that is that there can be great savings there. I ran 
into a
situation where program A was calling Program "Tax Calc" several times for each
transaction. The transactions were telephone calls, so there were many millions 
per
cycle.  A minor change to keep the "Tax Calc" from closing the files and going 
away
resulted in a reduction from 11 HOURS to 17 Minutes!!!

take care, and get well.
Bob

John Earl wrote:

> Al,
>
> Please don't take this personally, but a certain amount of skepticism is
> warranted for most of the folklore about performance on an AS/400.  I 
>understand
> what your
> Instructor was trying to convey, and technically he may be correct, but
> practically I just don't believe that there are any performance problems with
> qualified program calls.  Further, I have a hard time believing that even if
> there were a difference, it would be large enough to matter.  I guess the only
> way to tell for sure is to run a test....
>
> <Several hours later>
> OK, I'm done.
>
> I just ran a test on one of our /400's that would seem to indicates that your
> instructor's information is incorrect, outdated, or irrelevant.  The tests
> indicate that
> an unqualified call appears to take a little longer than a qualified call.  
>See
> below for the test results.
>
> <<SNIP>>

>
> For this test I created a program called "A" and put it in library "JOHN".
> Program "A" has a single statement:
>  C                   EVAL      *INLR = *ON
>
> By ending the program with LR on after each call, I am causing a security 
>lookup
> with each call to the program, rather than reusing an open version of the
> program.
>
> <<SNIP>>

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