RE: Externalize DB/IO (was What Counts as Technically Slick?)

["York, Albert" <albert.york@xxxxxxxxxxxxxx>]

Well, I can see what you are saying but I still think you are simply
duplicating services that the operating system provides.

I can 't see how you have really separated the DB function from your
program. All you've done is replace

          READ  MYFILE

with something like this: 

          CALL MYFILEIO
         PARM   RecordBuffer
         PARM  'READ' IOOption
         PARM   IOResult

They are both DB functions. It's just that the second one is your DB
function. If you change it, you then have to evaluate what the impact will
be on all of the programs that use it. In addition, it's one more thing that
a new programmer or a maintenance programmer has to know. What's the point?


Albert 


        -----Original Message-----
        From:   Nathan M. Andelin [SMTP:nathanma@haaga.com]
        Sent:   Monday, April 09, 2001 11:30 AM
        To:     MIDRANGE-L@midrange.com
        Subject:        Re: Externalize DB/IO (was What Counts as
Technically Slick?)

        >Date: Mon, 9 Apr 2001 08:41:36 -0700
        >From: "York, Albert" <albert.york@nissan-usa.com>
        >Subject: RE: What counts as technically slick?

        >On the surface it seems like a good idea,
        >but what have you gained?

        >I still have to define the record in my program,
        >so if the file changes I still have to change all the
        >programs that use that file.

        I was equally skeptical, Albert.  Until I tried it.  In my case, I
separate
        DB/IO and business rules into one module, and UI control into
another.  But
        I merge both modules into one program.  The interface between the
two
        modules is a single data structure for records, and a multiple
occuring data
        structure for record sets.

        I discovered a seemily natural boundary between DB/IO-Business Rules
and UI
        control.  Both modules, independent of the other are easier to
understand,
        debug, and maintain.  Faster compilation.  Smaller listings.  Also,
the
        modules, independent of the other provide better patterns for "reuse
by
        copy".  A productivity boost.

        Another surprise, I discovered that I can use the same DB/IO module
for both
        a Web interface as well as a 5250 interface - only the UI control
module
        changes.

        I don't predict this, but if someday SQL becomes better than record
level
        access for DB/IO, then only the DB/IO modules would change.

        A final surprise, while statically linked subprocedures are used
instead of
        read, update, delete, etc., the overhead is next to nil.  Not even a
        millisecond of difference in CPU usage for individual calls.

        Nathan.


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