diff --git a/doc/src/sgml/ref/create_event_trigger.sgml b/doc/src/sgml/ref/create_event_trigger.sgml
index 08894b22cf..040df11815 100644
--- a/doc/src/sgml/ref/create_event_trigger.sgml
+++ b/doc/src/sgml/ref/create_event_trigger.sgml
@@ -108,7 +108,14 @@ CREATE EVENT TRIGGER name
Notes
- To create a trigger on a event, the user must be superuser.
+ Only superusers can create event triggers.
+
+
+
+ Event triggers are disabled in single-user mode (see ). 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.
@@ -116,7 +123,7 @@ CREATE EVENT TRIGGER nameExamples
- Forbid the execution of any ddl command:
+ Forbid the execution of any DDL command:
CREATE OR REPLACE FUNCTION abort_any_command()
diff --git a/src/backend/commands/event_trigger.c b/src/backend/commands/event_trigger.c
index cb4e658a58..1edffee410 100644
--- a/src/backend/commands/event_trigger.c
+++ b/src/backend/commands/event_trigger.c
@@ -566,6 +566,25 @@ EventTriggerDDLCommandStart(Node *parsetree)
const char *tag;
EventTriggerData trigdata;
+ /*
+ * Event Triggers are completely disabled in standalone mode. There are
+ * (at least) two reasons for this:
+ *
+ * 1. A sufficiently broken event trigger might not only render the
+ * database unusable, but prevent disabling itself to fix the situation.
+ * In this scenario, restarting in standalone mode provides an escape
+ * hatch.
+ *
+ * 2. BuildEventTriggerCache relies on systable_beginscan_ordered, and
+ * therefore will malfunction if pg_event_trigger's indexes are damaged.
+ * To allow recovery from a damaged index, we need some operating mode
+ * wherein event triggers are disabled. (Or we could implement
+ * heapscan-and-sort logic for that case, but having disaster recovery
+ * scenarios depend on code that's otherwise untested isn't appetizing.)
+ */
+ if (!IsUnderPostmaster)
+ return;
+
/*
* We want the list of command tags for which this procedure is actually
* invoked to match up exactly with the list that CREATE EVENT TRIGGER