From cd3413ec3683918c9cb9cfb39ae5b2c32f231e8b Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Tue, 11 Dec 2012 19:28:31 -0500 Subject: Disable event triggers in standalone mode. Per discussion, this seems necessary to allow recovery from broken event triggers, or broken indexes on pg_event_trigger. Dimitri Fontaine --- src/backend/commands/event_trigger.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'src') diff --git a/src/backend/commands/event_trigger.c b/src/backend/commands/event_trigger.c index cb4e658a584..1edffee410e 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 -- cgit v1.2.3