RE: What are the benefits of ILE? -- RPG400-L

James W. Kilgore wrote:

> Just to toss a little gasoline on the fire, wasn't this "write once, use
> everywhere" handled by /COPY since the S/34?

As stated in an earlier thread:

The biggest problem with copy is that the variable names will be globally
defined and that you must always watch out for variable/indicator duplicates.

Using ILE procedures you don't need to plan for or think of this possibility,
but can concentrate on the procedure logic without leaving all indicators
(and sometimes variables) in the same state on routine exit as on entry.

With hundreds or maybe thousands of users, program (and consequently job) size
still matters, and program size increase when /COPY is be used.

> 
> As someone else posted, make it a callable program.
> 

Noone would ever even think of making one program for retrieving each field 
of a database file, but using ILE I have created service programs where
a lot of the procedures return the content of a database field. 
Eg. CustGetName, CustGetCity, CustGetKeyAcc, etc.
This simplifies database changes in that most file access takes part in one
ILE RPG module. Compare this to the 'normal' scenario where frequently used
files produce a multipage report in a 'where-used' listing.

> IMHO, the purpose of ILE was not to replace /COPY or callable 
> programs.  The
> machines have gotten faster so the performance hit on a CALL 
> becomes a moot
> point.  AFAIK, the purpose of ILE is in file scopeing. Overrides 
> and ODP's and
> commitment control and all that.
> 
> I think that we all must take a historical perspective on the IBM midrange
> systems and -why- certain features are made available.
> 
> IBM creates a midrange system for maybe 3 customers.  Like the U.S. Postal
> service or Farmers Insurance or Costco.  Now in order for a 
> manufacturing plant
> to be cost effective it must produce at or near plant capacity.  
> So the excess
> machines made for the chosen few are unleashed to the masses.
> 
> Now because one of the chosen few have a software design problem, ILE file
> scopeing (at the OS level), saves the chosen few development 
> bucks and keeps them
> in the IBM fold.
> 
> IMNSHO ILE is not for the masses but the chosen few.
> 

IMHO this would be like saying that DLL's are for the chosen few PC programmers.




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