RE: How to break up a LARGE physical fil

[Brian Johnson <brian@xxxxxxxxxxxxxxx>]

How about a record format selector program?  I've never used one, but   
it's there on the CRTLF command (FMTSLR).  Programs specify the file name   
for all IO operations, and the format selector program selects the format   
name for record inserts.  Only the format selector needs to know the   
record format names.  Sounds simple, I wonder if it works?  See the   
DB2/400 Programming manual for more information.

 --
Brian Johnson
Help/Systems, Inc.
brian@helpsystems.com

 ----------
From:  Pete Hall
Sent:  Wed, Jul 16, 1997 19:31 PM
To:  brian; 'mail@uucp <MIDRANGE-L@midrange.com>'
Subject:  How to break up a LARGE physical file

>>
Basically he wants to divide his data by year, and requires both
lookup and update of ANY record. He had tried breaking the file
up and then using logicals with joins to see the whole base when
required. Lookups are fine but updates die. He didn't have the msg
handy when he called just something about not being allowed. <<

Kirk,

Joins are not updatable on the AS/400. This process is probably better
suited to a multiple format logical anyway. One generally thinks of
multiple format logicals as being analagous to the old
header-followed-by-detail kind of transaction data, however, there is
absolutely no reason that all of the records can't be identical. The
only problem is the "no changes" requirement. If he is willing to accept
"small" changes, then you may be able to do something. You will need to
make the record names unique (perhaps incorporating the year) and
updates (and writes as well) will need to specify the appropriate record
name. For updates, the record name can be determined from the file
information data structure, but for writes, you'll need logic to
determine what the correct value is, and in RPG at least, the names must
be literals, so some maintenance would need to be done annually. Perhaps
you could use "CurrYear" as the record name for the current year if only
current year data must be updated. Then the record names would have much
less significance.

Pete


 --
 - Pete Hall peteh@earth.inwave.com
http://www.inwave.com/~peteh/

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