Re: RPG IV Performance

[Mike.Barton@xxxxxxxxxxxx]

Lisa
     this is going to get the list very busy !

>The program they showed me was written in RPGIII, and I made my usual
request to
>an outside contractor that this be done in RPGIV.

On the AS/400 they are now RPG400 as RPGIII is only on a system/38 (AFAIK)

>His response was "Sure, if
>you want the program size to be 5 - 10 times the size of an RPGIII
program."


I have just compiled & converted a simple program withe the following
resultant sizes
(we are V4R4 by the way)

                             RPG400         RPG4
after compilation            102400       159744
after RMVOBS(*ALL)            57344        61440

all sizes are in bytes. (RPGIV compiled as DBGVIEW(*STMT))

So from the above evidence, theres not too much difference - especially
after
removing observability (wheteher you would want to do this is a different
matter
though)

>When I asked him to explain that, he only said that, in his experience,
this is
>always true, and that it would have a very negative performance.  I even
>mentioned removing observability (not that I really understand what that
means,
>but I just read something the other day about that being a way to reduce
program
>size!), and he said that might move it down to 3 - 5 times the size of an
>equivalent RPGIII program.  The program will only be about 50 - 100 lines
of
>code.

>Can someone explain if this is true, and, if so, why?  And, if true, what
does
>this really mean from a performance standpoint?


From the above (un-scientific) test, it is true the objects are larger by
about 50%
when compiled as RPGIV but nowhere in the order of what he claims.

As regards performance, there are other better qualified persons on the
list who will
no doubt respond to this.

Mike


+---
| This is the RPG/400 Mailing List!
| To submit a new message, send your mail to RPG400-L@midrange.com.
| To subscribe to this list send email to RPG400-L-SUB@midrange.com.
| To unsubscribe from this list send email to RPG400-L-UNSUB@midrange.com.
| Questions should be directed to the list owner/operator: david@midrange.com
+---