Function EventTriggerTableRewrite

src/backend/commands/event_trigger.c:807–867

* Fire table_rewrite triggers. */

 * Fire table_rewrite triggers.
 */
void
EventTriggerTableRewrite(Node *parsetree, Oid tableOid, int reason)
{
	List	   *runlist;
	EventTriggerData trigdata;

	/*
	 * See EventTriggerDDLCommandStart for a discussion about why event
	 * triggers are disabled in single user mode.
	 */
	if (!IsUnderPostmaster)
		return;

	/*
	 * Also do nothing if our state isn't set up, which it won't be if there
	 * weren't any relevant event triggers at the start of the current DDL
	 * command.  This test might therefore seem optional, but it's
	 * *necessary*, because EventTriggerCommonSetup might find triggers that
	 * didn't exist at the time the command started.
	 */
	if (!currentEventTriggerState)
		return;

	runlist = EventTriggerCommonSetup(parsetree,
									  EVT_TableRewrite,
									  "table_rewrite",
									  &trigdata);
	if (runlist == NIL)
		return;

	/*
	 * Make sure pg_event_trigger_table_rewrite_oid only works when running
	 * these triggers. Use PG_TRY to ensure table_rewrite_oid is reset even
	 * when one trigger fails. (This is perhaps not necessary, as the
	 * currentState variable will be removed shortly by our caller, but it
	 * seems better to play safe.)
	 */
	currentEventTriggerState->table_rewrite_oid = tableOid;
	currentEventTriggerState->table_rewrite_reason = reason;

	/* Run the triggers. */
	PG_TRY();
	{
		EventTriggerInvoke(runlist, &trigdata);
	}
	PG_FINALLY();
	{
		currentEventTriggerState->table_rewrite_oid = InvalidOid;
		currentEventTriggerState->table_rewrite_reason = 0;
	}
	PG_END_TRY();

	/* Cleanup. */
	list_free(runlist);

	/*
	 * Make sure anything the event triggers did will be visible to the main
	 * command.