Remove duplicated comment block in event_trigger.c

The reasons why event triggers are disabled in standalone mode are
documented in the code path of ddl_command_start, and other places
checking if standalone mode is enabled or not mention to refer to the
comment for ddl_command_start, except for table_rewrite that duplicated
the same explanation.

Reported-by: David G. Johnston
Discussion: https://postgr.es/m/CAKFQuwYqHtXpvr2mBJRwH9f+Y5y1GXw3rhbaAu0Dk2MoNevsmA@mail.gmail.com

diff --git a/src/backend/commands/event_trigger.c b/src/backend/commands/event_trigger.c
index 918b9b4d8fa21ab8362a8140571bdec59a53c13a..02ab40eaac757a15868fc05a3a99b9d4a0e6da6f 100644 (file)
--- a/src/backend/commands/event_trigger.c
+++ b/src/backend/commands/event_trigger.c
@@ -833,20 +833,8 @@ EventTriggerTableRewrite(Node *parsetree, Oid tableOid, int reason)
        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.)
+        * See EventTriggerDDLCommandStart for a discussion about why event
+        * triggers are disabled in single user mode.
         */
        if (!IsUnderPostmaster)
                return;