Re: Database Re-eng

[DAsmussen <DAsmussen@xxxxxxx>]

Walden,

In a message dated 98-04-03 20:07:25 EST, you write:

<<snip>>
> However, while I agree with your PF views I don't completely agree with you
>  Field Reference File views. FRFs should define a domain, not a data type. I
>  agree that the customer number in the order file and the customer file
>  should refer to the same field in the FRF, but why would you have all the
>  dates refer to a single date field? A date is a data type, not a domain.
>  What in the world does a customer order date have to do with a item
>  expiration date?

I know, I know.  From a "database purist" standpoint, dates shouldn't be in
the field reference (you should just use a date data type, as the same type of
date should not be replicated across files under normalization rules).  From a
"database realist" standpoint, however, I must disagree.  Files, fields, and
parameters have become too numerous in today's complex software packages to
adequately track and evaluate them.  BPCS provides a good case in point -- all
dates passed between the newly modularized inventory transaction processing
system are eight positions, with two exceptions (which we've had to manually
correct ourselves).  Had the latter been externally referenced, they wouldn't
have been missed.

While I realize that Y2K _MAY_ present a unique instance of this, who knows?
The US, Canadian, or EU governments could mandate at some point that all dates
for international commerce be reported to them in "EBCDIC packed, reversed
Polish notation, consisting of 27 decimal characters".  Some person takes
power with a cousin that does programming, and there's no telling what can
happen.  Simply "flipping a switch" in the data dictionary under this
circumstance would certainly be easier than what we're going through now!  A
date could, indeed, constitute a domain in this circumstance...

JMHO,

Dean Asmussen
Enterprise Systems Consulting, Inc.
Fuquay-Varina, NC  USA
E-Mail:  DAsmussen@aol.com

"Never go to bed mad.  Stay up and fight." -- Phyllis Diller
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