Triggers

Informix^® and ORACLE provide triggers with similar features, but the trigger creation syntax and the programming languages are totally different.

Informix triggers define the stored procedures to be called when a database event occurs (before | after insert | update | delete ...), while ORACLE triggers can hold a procedural block.

In ORACLE, triggers can be created with 'CREATE OR REPLACE' to keep privileges settings. With Informix, you must drop and create again.

ORACLE V8 provides an 'INSTEAD OF' option to completely replace the INSERT, UPDATE or DELETE statement. This is provided to implement complex storage operations, for example on views that are usually read-only ( you can attach triggers to views ).

ORACLE allows you to create multiple triggers on the same table for the same trigger event, but it does not guarantee the execution order.