Re: COBOL ILE

[Jim Essinger <esinger@xxxxxxxx>]

Greetings Geir;

The old adage is good - If it ain't broke, don't fix it.

Start when there is a major change to do, or a complete new system or
rewrite.  Start by using the date, time and timestamp data types in
your files and programs.  Utilize the intrinsic functions.  The
can all be done without changing a bunch in the program.

You can simply take your old code, and change the type to CBLE (or is it
CBLLE? not at work, can't remember) and recompiling.  This will
USUALLY work fine, but there are some issues where ILE COBOL works
different than OPM COBOL.  I don't remember what exactly they are,
but it has to do with running in different activation groups.

ILE is best for modular programming, and that means breaking up the
programs into modules that do a particular function. You might look at
the procedures in your programs and seeing if there is common code in
them.  Put the common code in to a module (each module being unique)
and then putting the modules together in service programs.  
(Please see the other message I posted)

Then you have to make a choice about binding the program modules
together.  There is "static" binding and
"dynamic" binding.  The difference in programming is how
the call works.  The difference in compiling is that
"static" is bound into the program at compile time and the 1st
run is faster.  If you call a module 1,000,000 times each night from
another program (new instances), you will get better performance with
"static" binding.  You will also have to recompile all
programs that have the module bound to them if/when that module
changes.  

Dynamic binding happens at run time.  This means that the first call
will be slower as the AS - iSeries 400 resolves the binding on the
fly.  All subsequent calls to that module will be just as fast as
the "static" bound program. The nice thing about
"dynamic" binding is that you can change the module being
called, and the next execution of the calling program will pick up the
change.  This might be the best choice if a module is used in a lot
of programs.  You would then have the ability to make the change one
time, and then all the programs that use the module would be up to date
the next time they run.  Great for those common functions such as
(for our shop) interest  calculation changes and applying payments to
accounts.

You also can take advantage of activation groups and pointers, if you
want to get into those things.  Pointers can be great for system
programmers who would like to use some of IBM's API programs to get lists
of spool files, users, etc.  It took some time to get my mind around
the pointer concept, but I do like the function.  

There is a bunch more, but then there always is.  Hope this helps
you get started.

Jim Essinger
Senior Programmer/Analyst
Student Loan Fund of Idaho 
Work: 208-452-4058 
Fax:    208-452-5848
A

t 09:30 AM 5/28/2001 +0200, you wrote:

> Hello,
> Rick. 
>
> You are obviously in a situation just like a lot of
> us old 'OPM'ers'.  We know that ILE exists, and we recognize the
> advantages,  but how the h... shall we get started??  If
> anybody out there have good ideas, adresses to useful web-sites etc. I
> would greatly appreceate it.  
>
>
> Mvh.
>
> Geir Kildal
>
>
>
>
> "chocolate_thunder1"
> <chocolate_thunder1@yahoo.com> 
> Sent by:
> owner-cobol400-l@midrange.com 
>
> 26.05.01 04:50 
> Please respond to COBOL400-L
>        
>        
> To:       
> <COBOL400-L@midrange.com> 
>        
> cc:         
>        
> Subject:        COBOL
> ILE 
>
>
>
> Hello All, 
>               
> I'm trying to find out more information on COBOL ILE on the AS/400. 
> I'm  not new to AS/400 COBOL but very new to ILE and some of the
> concepts. (Binding  directories, Service Programs, etc)  I have
> a project that is coming up and  I would love to do it in ILE but I
> need to get a comfort level with it  first.  I don't want to
> just write OPM's and then make them ILE I don't  believe you get as
> much bang for the buck that way.  I would really  appreciate
> any suggestions!!  
>   
> Thanks in advance 
>   
> Rick Smith 
>   

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