Re: Need Help

["Kahn, David" <KAHN@xxxxxxxxxxxxxxxxxx>]

Booth Martin (boothm@earth.goddard.edu)

>Now I am curious:  Aside from all of the laughing about Dave's
>punishments, how efficient is MR logic?  Is it fast? Effective? Compared
>to what?

Booth,

Actually the RPG cycle itself is fast and effective in execution and can
have extreme brevity of source code. It's always been quick and easy to
code using the cycle, once you got over the steepest bit of the learning
curve, and it's always been possible to sidestep the cycle, even in
RPG/II. Cycle programming became disreputable once structured opcodes
were introduced into RPG/III. Structured programming gives you complete
control over the program logic, lets you break the program into small
pieces that are easier to code, and lets you write programs that are
easier to read and to desk check.

The cycle is arguably still superior in batch processes where you have
to blast right through one or more files, especially when matching them.
It's very easy for logic errors to creep into even a structured program.
For example, will it work when the last record on one or both files
validly contains high-value in the matching key? However, the RPG MR
logic is already written for you and it's guaranteed to be sound; you
just have to specify what happens at each stage in the cycle. Notice how
everyone claims to have abandoned the RPG cycle years ago, or they say
they once used it but never got to grips with the "difficult" MR logic,
but whenever matching records come up about half a dozen MR code
examples pop up?

It's strange how matching files has become something of a rarity, when
it used to be that almost every program we wrote was file matching.
Sorted transactions and the master file would be read in and rejected
transactions, the next generation of the master file, the error report,
and the reconciliation report would be churned out. It must be these new
fangled disk drives and CRTs that have made the difference. :-)


Dave Kahn - TCO, Tengiz, Kazakstan
=========

e-mail:  kahn@tengizchevroil.com    (until August 5th)
         dkahn@cix.compulink.co.uk  (from  August 6th)

Note new e-mail address in Kazakstan
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