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CREATE EVENT TRIGGER(7) PostgreSQL 9.5.0 Documentation
CREATE_EVENT_TRIGGER - define a new event trigger
CREATE EVENT TRIGGER name
[ WHEN filter_variable IN (filter_value [, ... ]) [ AND ... ] ]
EXECUTE PROCEDURE function_name()
CREATE EVENT TRIGGER creates a new event trigger. Whenever the
designated event occurs and the WHEN condition associated with the
trigger, if any, is satisfied, the trigger function will be executed.
For a general introduction to event triggers, see Chapter 37, Event
Triggers, in the documentation. The user who creates an event trigger
becomes its owner.
The name to give the new trigger. This name must be unique within
The name of the event that triggers a call to the given function.
See Section 37.1, "Overview of Event Trigger Behavior", in the
documentation for more information on event names.
The name of a variable used to filter events. This makes it
possible to restrict the firing of the trigger to a subset of the
cases in which it is supported. Currently the only supported
filter_variable is TAG.
A list of values for the associated filter_variable for which the
trigger should fire. For TAG, this means a list of command tags
(e.g. 'DROP FUNCTION').
A user-supplied function that is declared as taking no argument and
returning type event_trigger.
Only superusers can create event triggers.
Event triggers are disabled in single-user mode (see postgres(1)). If
an erroneous event trigger disables the database so much that you can't
even drop the trigger, restart in single-user mode and you'll be able
to do that.
Forbid the execution of any DDL command:
CREATE OR REPLACE FUNCTION abort_any_command()
RAISE EXCEPTION 'command % is disabled', tg_tag;
CREATE EVENT TRIGGER abort_ddl ON ddl_command_start
EXECUTE PROCEDURE abort_any_command();
There is no CREATE EVENT TRIGGER statement in the SQL standard.
ALTER EVENT TRIGGER (ALTER_EVENT_TRIGGER(7)), DROP EVENT TRIGGER
(DROP_EVENT_TRIGGER(7)), CREATE FUNCTION (CREATE_FUNCTION(7))
PostgreSQL 9.5.0 2016 CREATE EVENT TRIGGER(7)