Data Transformation Engine Database Interface Designer Reference Guide

Chapter 9 - Database Triggers Database Triggers Overview
Database Interface Designer Reference Guide
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The following is a diagram illustrating the functionality and relationship of these
tables.
Maintaining Triggering Tables
The current implementation of the triggering functionality should be self-
maintaining. However, there are unusual situations in which some user
maintenance may need to be performed:
♦ Handling Unexpected Shutdowns
♦ Handling Truncated Tables
Handling Unexpected Shutdowns
Note Make sure that there are no other Event Server systems running on the target
DBMS before running the maintenance operations listed below.
If an Event Server system (containing database triggers) has encountered an
unexpected shutdown and cannot be re-started and subsequently shut down in a
normal sequence, you must re-run the triggering installation script (specific to your
database) to clean up any triggering resources that have been left behind on the
target DBMS. This is because when an Event Server is prematurely shut down, any
defined database triggers will remain in operation on the backend DBMS (for
example, Oracle) until the same system is re-started and then properly shut down.
The database triggers will continue to monitor for events while the Event Server is
shut down, thus enabling the system to be fault-tolerant with respect to any
database changes that occur during an unexpected downtime. This fault-tolerant
behavior requires that a normal system shutdown eventually take place.