RE: Diff between static binding and dynamic binding

[Buck Calabro <mcalabro@xxxxxxxxxxxx>]

This subject comes up fairly often on the RPG list; perhaps some of the
veterans could review my reply and see what improvements could be made so we
can have a "standard" reply?!

First, there are several good books that you can read which give very good
information on the subject - see http://www.midrange.com for links to good
books in our field.  These books will answer quite a few questions besides
this one...

IBM have a web site where you reference every AS/400 manual!  It is 
http://publib.boulder.ibm.com/html/as400/onlinelib.htm

Here is a specific link to the ILE concepts manual:
http://publib.boulder.ibm.com:80/cgi-bin/bookmgr/BOOKS/QB3AQ702/CCONTENTS

To very briefly answer your specific questions,
Q. What is the difference between Static and Dynamic binding?
A. Dynamic binding is the "traditional" way for one program
    to call another.  Static binding is the "ILE" way.  Static
    binding is much faster at run time than dynamic binding.

Q. What is the difference between a dynamic program
    call and a static procedure call?
A. With dynamic binding, the "connection" between the 
    two programs happens at the moment the CALL 
    operation is executed.  Between finding the program 
    in the library list, verifying authority, opening the files 
    and initialising the variables, this can be a long process 
    (several seconds.)
    With static binding, almost all of the work (aside from 
    variable initialisation and file opens) takes place at compile
    time.  This makes a static call fast.

Q. What difference does it make to the programmer?
A. If you currently program using many CALL operations,
    you can transition pretty quickly to CALLP because
    you're used to dealing with parameters.  Service programs
    are very much like a library of commonly used
    procedures.
    If you don't currently program with many CALLs, you'll
    need to get used to the idea of local variables, and
    accessing them via parameters.

Q. What is the advantage of static binding?
A. Speed.  We can finally break up our large programs into
    smaller, easier to read and maintain units without a
    performance penalty.

Buck Calabro
Aptis; Albany, NY
mailto:Buck.Calabro@aptissoftware.com

> -----Original Message-----
> From: A.Vishnu Vardhan 
> Sent: Wednesday, September 22, 1999 8:58 AM
> To:   RPG400-L@midrange.com
> Subject:      Diff between static binding and dynamic binding
> 
> Hi all,
> 
> I would like to know the difference between 
> 1)Static binding and dynamic binding
> 2)Dynamic program call and Static procedural call
>   
> Differnce interms of compilation, Execution,
> advantages and disadvantages.
> 
> Thanks in advance.
> 
> Vishnu Vardhan A
> AS/400 programmer    
> 
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