RE: Triggers, the library they reside in, and restoring the libra ry

Please send me your trigger mediator programs/tables if you're still
willing...thanks!

Mary Koetting
Senior Programmer Analyst
Missouri Consolidated Health Care
573-526-2856
 

-----Original Message-----
From: Alan Campin [mailto:Alan.Campin@xxxxxxx] 
Sent: Friday, June 17, 2005 3:35 PM
To: midrange-l@xxxxxxxxxxxx
Subject: Triggers, the library they reside in, and restoring the library


>> If a file is restored, does it fire the trigger for each record
>> restored? - i.e. should I remove the trigger before and re-add it
>> after, as part of the process of restoring the file?

>> if a file with a trigger is restored, should the trigger be restored
>> with it - i.e. should the trigger reside in the same library as the
>> file (TRGLIB on ADDPFTRG command)?  or does it matter?

I sent the following on another question on triggers. The mediator, also,
solves the restore problem because it is what is restored, not the actual
program and, yes, the trigger program should be in the library of the data
file. That is where the trigger mediator is normally installed. Since the
trigger mediator calls service programs, where they are located is up to
you. 

>> We think a very good architecture for triggers is to make a CL program
the
>> actual trigger program that calls an RPG program to do the work, passing
the
>> appropriate parameters.  That allows you to modify the RPG program
without
>> having to remove & add the trigger on the file.

I see all kinds of problems with that, the first being that CL programs have
to be loaded every time they are called. Lot of overhead.

I have a much better solution called a Trigger Mediator. The trigger
mediator lives between the data base and the trigger service program. Using
the trigger mediator, you can instantly add or remove tables from triggers
and instantly add or remove all tables from triggers. The trigger mediator
program itself never needs to be modified. Everything is table driven. The
best part to me is that everything is extremely fast and you can modify the
trigger service programs without bringing down the entire system. 

I would be glad to send you a copy of the trigger mediator and the
associated programs to maintain the trigger tables if you want to use it.