RE: What is Performance

> From: Dieter Bender
> 
> thats one of the misteries, that might have been true some years ago,
or
> that might be true for a liitle 170. But today on recent hardware
> its simply not the truth.

Prove it.


> For simple transactions (like read a record, or do one single update)
> there might be an advantage for rpg, but you have to pay a price for
> this, you have to code every line by hand and changes in database
> or retrival logic has more maintenance afford, compared to modern
> languages like java, where you can use mapping tools for instance.

This simply isn't the case.  I can still code business rules faster in
RPG than in Java.  And maintenance is easier in RPG.  You may not think
so, you may code faster in Java.  But that's okay, because it has
NOTHING TO DO with the performance of the program.  Let's stick to one
subject at a time.


> This advantage would be in the range of 3 to 5
> times faster for rpg to well done java code. If you get 10 to 100
times,
> there must be a problem with the design of the java code.

Prove it.


> For complex transactions java might be even faster than rpg, if you
use
> multithreading in java to get benefit of parallelism.

Dieter, have you ever multi-threaded a real business transaction?  How,
for instance, would multi-threading provide you a benefit when entering
an order?  Please show us some example code that runs faster than RPG.
And, as you say, this means you can't use EJBs.  You also can't use
tools, because there are no tools that generated multi-threaded code.


> Putting this together today a rpg solution might be about 3 times
faster
> for one user compared to a well designed java application doing
> comparable work. Besides the fact (some like others not) that green
> screen is diappearing lets have a look how applications scale and
> let's begin with 5250.

Prove it.


> And now lets have a closer look at the java rpg mix and ist
scalability.

(snip of a bunch of stuff about how calls to RPG aren't scalable.)

Dieter, your arguments are unsubstantiated.  You base them on some
assumptions about synchronization that simply aren't proven.  For
example, in my architecture each session gets its own job and
communicates with the JVM via data queues.

In any case, I no longer will respond to your general statements about
performance until I see some working code that supports your claims.
Please feel free to write some code that backs up your statements and
present it here.  Then we can talk.  Until then, it's all supposition
and a waste of time.

Joe