RE: Logical Files vs. Physical Keys

[Chris Bipes <rpg@xxxxxxxxxxxxxxx>]

Yes you can use unique keyed logicals to force your physical unique, that is
until the logical gets its data member removed, thus no index maintained,
and some batch program updates the physical.  Now the logical member cannot
be added back because of duplicate unique keys.  OOPS! some green program
just caused you a big headache in scrubbing the data to remove the
duplicates or re-assign the unique keys.  Gee what aux files have the key
you need to scrub and which record goes to which?  

Ok that's a worst case scenario but can be prevented by putting the unique
key directly on the physical.  I have had the index of a physical get
corrupted during a power failure and the ups blowing a fuse.  It was real
easy to recapture ALL the data to a new, freshly compiled, physical with a
simple CPYF FROMRCD(1).  JMHO and bad experience, it is better to put the
lowest level unique key on the physical for forcing the data to remain
unique always.

Christopher K. Bipes     mailto:ChrisB@Cross-Check.com
Sr. Programmer/Analyst   mailto:Chris_Bipes@Yahoo.com
CrossCheck, Inc.         http://www.cross-check.com
6119 State Farm Drive    Phone: 707 586-0551 x 1102
Rohnert Park CA  94928 Fax: 707 586-1884

If consistency is the hobgoblin of little minds, only geniuses work here.
Karen Herbelin - Readers Digest 3/2000


-----Original Message-----
From: Kaynor@aol.com [mailto:Kaynor@aol.com]
Sent: Thursday, March 23, 2000 7:46 PM
To: MIDRANGE-L@midrange.com
Subject: Logical Files vs. Physical Keys


Chris,
The reasons you give for keying the physical can be achieved by using the 
UNIQUE keyword on a logical.  Keeping your physicals unkeyed is arguably 
better because of the flexibility it provides.  
--Chapin Kaynor
  Vermont
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