Re: Trigger Mediator

[Alan Campin <Alan.Campin@xxxxxxx>]

>> Ok, I'll bite. What's a trigger mediator?

>From the documentation:
What is a Trigger Mediator?
A Trigger Mediator is a program that mediates trigger requests between the 
iSeries Database (DB2) and a trigger service programs. By mediate, we mean, DB2 
calls the trigger mediator and the mediator, in turn, calls the correct trigger 
service program. It "Mediates" all requests. 

 

By using a mediator, we have the ability to, remove all tables from triggers, 
activate triggers on all tables, add new table to triggers, remove a table from 
triggers, all instantly. 

 

Triggers are powerful tools to capture changes made to the DB2 database but 
triggers have several problems that make them difficult to use. 

 

  1.. Triggers put an exclusive lock on the trigger program. It cannot be 
removed except by removing the trigger from the table. If errors are detected 
in the trigger program, they cannot be corrected without removing the table 
from triggers. 
  2.. Triggers put an exclusive lock on tables when they are under trigger 
control. They cannot be deleted or changed while under trigger control.
  3.. When enabling a trigger, you must put the name of the individual program 
to call for each event, Add, Update, Insert. 
  4.. The only way to disable triggers is to remove triggers from all tables. 
  5.. Triggers cannot be disabled except by removing the trigger from the table 
and then adding the trigger back. 
  6.. Triggers can represent security risks. 
 

The Trigger Mediator solves all these problems.