RE: Expensive op codes

Even if we seemed to disagree in the past about optimization, I think the
phrase "relatively inexpensive fast hardware" is the key.  I'm prodigal with
machine resources for things like building screens for interactive programs.
Who really cares about .001 sec vs .1 sec? (I made that up, but it is two
orders of magnitude.  There are probably some things to consider for large
numbers of concurrent users in the same application, too.)  I think where
you can make a case for being frugal with machine resources is the batch job
that runs over millions of records where you have a choice of doing
something cheap or expensive several million times.  That can add up to a
noticeable difference.  

I am curious about the sorts of things that can help me improve batch
performance.

> -----Original Message-----
> From: Peter Dow [mailto:pcdow@yahoo.com]
> Sent: Friday, October 15, 1999 2:29 PM
> To: RPG400-L@midrange.com
> Subject: Expensive op codes
> 
> 
> > Barbara Morris wrote:
> 
> > With date operations, the contest should be regarding the 
> number of date
> > opcodes, not the number of statements.  (Date opcodes are 
> very expensive.)
> 
> > Hans Bold wrote:
> > Ah, another FAQ!  A long time ago, I did a comparison
> > comparing the performance of the old MULT 100.0001 trick.
> > I found that using MULT was about 100 to 150 times slower
> > than doing the date conversion using a couple of moves.
> 
> I'd be very interested in a discussion of just how "expensive" various
> opcodes are and how much of a difference it makes in a 
> typical business
> application. In these days of relatively inexpensive fast 
> hardware, my rule
> of thumb has been to spend more time optimizing I/O than 
> worrying about how
> many MULT, ADDDUR, etc. op codes I  use. I tend to prefer 
> solutions that
> require fewer source statements unless there is solid 
> evidence that it will
> noticeably impact performance.
> 
> Which is faster, ADD 1 X or EVAL X=X+1?  READE or READ then IF
> key='constant'? Is there a list of FAQ's about this?
> 
> Peter Dow
> Dow Software Services, Inc.
> 909 425-0194 voice/fax
> 
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