atabase triggers are specialized stored programs. They’re never called directly because they’re called indirectly by Data Definition Language (DDL) or Data Manipulation Language (DML) statements. The call is indirect because triggers wait in the background, listening for events, such as DDL or DML statements. When the events occur, they fire (call) triggers. Beyond DDL and DML statements, Oracle Database 11g also supports instead-of triggers for non-updateable views and system or database event triggers. On the other hand, MySQL supports DML statement triggers only for the INSERT, UPDATE, and DELETE statements.