RE: Logical Files vs. Physical Keys

[Kaynor@xxxxxxx]

Chris,
I can see why you feel this way if you work in an environment where people 
who don't know what they are doing remove members from LFs.  You might want 
to limit their authority.  I'll stick to the  statement that nonkeyed PFs are 
arguably better than keyed PFs because of flexibility.  If you reserve one LF 
for all updates as part of your record locking strategy, this LF can be the 
one with the UNIQUE keyword.   On this issue, consistency is probably 
essential no matter what strategy you use (in spite of your signature quote).
--Chapin Kaynor

> 
>  Date: Fri, 24 Mar 2000 07:47:37 -0800
>  From: Chris Bipes <rpg@cross-check.com>
>  Subject: RE: Logical Files vs. Physical Keys
>  
>  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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