RE: Using CHAIN instead of SETLL AND READE to begin a loopwhich reads a group

It would appear that, if FIFO-like sequencing is absolutely a requirment,
and you don't want that issue to be a career-defining moment when someone
changes the file to REUSEDLT(*YES) [*1], perhaps the file design should
include a record-add sequence counter field.  This field would be used as
the last significant key field in any access path requiring FIFO.  Just an
idea.

[*1] I am acknowledging the fact that REUSEDLT(*YES) & FIFO are not allowed;
but I have seen the scenario where someone CHGPF'd a file with FIFO removed,
and REUSEDLT(*YES) specified.  It wasn't pretty.

- Dan Bale
(I am *NOT* "Dale"
http://archive.midrange.com/midrange-l/200105/msg00281.html )
SAMSA, Inc.
989-790-0507
DBale@SAMSA.com <mailto:DBale@SAMSA.com>
  Quiquid latine dictum sit altum viditur.
  (Whatever is said in Latin seems profound.)

-----Original Message-----
From: rpg400-l-admin@midrange.com [mailto:rpg400-l-admin@midrange.com]On
Behalf Of M. Lazarus
Sent: Tuesday, May 14, 2002 4:35 PM
To: rpg400-l@midrange.com
Subject: Re: Using CHAIN instead of SETLL AND READE to begin a loopwhich
reads a group


At 5/14/02 09:36 AM, you wrote:
>DDS keyword FIFO requires that you not reuse deleted records. Typically,
>it is a very bad idea to create files without the attribute set to allow
>the system to reuse deleted records.

  I was pretty sure that that was the case.


>Even in a case where you might determine that it is okay to not allow
>the system to reuse deleted records today, tomorrow might be a different
>story. In such a case, you would be facing a problem because the key
>structure doesn't suffice.

  If you are explicitly putting the FIFO keyword in the source, then that
is a deliberate design decision and should be respected as such.  There's
no right or wrong there.


>And what happens to the arrival sequence path if you copy the file or
>reorganize it over the key fields?

  I'm not sure, since I haven't had a need to try this.  Would FIFO
sequencing be retained?

  -mark