Ours as well-- IIRC, in the early S/38 / AS/400 days the thought was that since a Physical File consisted of the data portion and an index, you were out of luck if the index got corrupted-- you'd lose your master file!
Of course, in most cases you could CPYF FROMRCD(1) to read by RRN instead of by key, and salvage your data.
The problem was overblown; but some applications...
Paul E Musselman
From: MIDRANGE-L [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Rob Berendt
Sent: Monday, August 28, 2017 1:58 PM
To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
Subject: RE: Database design question
That being said however, our ERP package has no primary nor unique keys on
the underlying table. They have a key on some of the logicals but do not
specify unique. In theory you could have duplicate keys but their
programming logic doesn't permit it (from transactions done within the
I think the thing was 40 years ago there was certain corruption which was
easier to recover from if your table did not have any keys on it. Don't
laugh, I think that is really the reason.
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