Re: Data base triggers

[dhandy@xxxxxxxxxxx (Douglas Handy)]

Booth,

>And why not just 
>always set the parm at *YES?  What is the downside?  What protection or 
>efficiency does it provide?

I think the main protection is against inadvertent changes to the
buffer.  ALWREPCHG() wasn't added until V3R2 and V3R7, so the
(shipped) default has to be *NO to remain backward compatible.

This is not unlike the situation when you change a RPG program file
from input only to update and rewrite the entire record format with
UPDATE.  If (for whatever reason) a previous programmer had mucked up
some fields instead of using separate stand-alone variables, the
database gets updated.

Having a default of *NO ensures backward compatibility.  The
efficiency is probably a minor non-issue, since it would presumably
deal with the buffer as a whole upon return from the trigger program.

The addition of ALWREPCHG(*YES) is great, especially for things like
setting last change user/timestamp stuff or some dynamic defaults.  A
number of people also used (use?) it for Y2K database changes to sync
dates between a 6-digit date field and a 8-digit date or date data
type field.  The trigger just detects which changed and syncs the
other field to match.

Doug
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