I had never heard this being recommended because of corrupt indexes but because a CPYF on an unkeyed physical run 10 times faster than a keyed physical. Even just using RPG to read an unkeyed file would run much faster than a keyed one. Database would block an unkeyed file when read. I think that is ever still true today although less noticeable due to the speed of todays systems.
-----Original Message-----
From: MIDRANGE-L [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Musselman, Paul
Sent: Monday, August 28, 2017 4:44 PM
To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
Subject: RE: Database design question
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
PaulMmn@xxxxxxxxxxxxx
-----Original Message-----
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
*SNIP*
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 programming logic).
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.
*SNIP*
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