Function AfterTriggerSetState

src/backend/commands/trigger.c:5332–5642

---------- * AfterTriggerSetState() * * Execute the SET CONSTRAINTS ... utility command. * ---------- */

 * ----------
 */
void
AfterTriggerSetState(ConstraintsSetStmt *stmt)
{
	int			my_level = GetCurrentTransactionNestLevel();

	/* If we haven't already done so, initialize our state. */
	if (afterTriggers.state == NULL)
		afterTriggers.state = SetConstraintStateCreate(8);

	/*
	 * If in a subtransaction, and we didn't save the current state already,
	 * save it so it can be restored if the subtransaction aborts.
	 */
	if (my_level > 1 &&
		afterTriggers.trans_stack[my_level].state == NULL)
	{
		afterTriggers.trans_stack[my_level].state =
			SetConstraintStateCopy(afterTriggers.state);
	}

	/*
	 * Handle SET CONSTRAINTS ALL ...
	 */
	if (stmt->constraints == NIL)
	{
		/*
		 * Forget any previous SET CONSTRAINTS commands in this transaction.
		 */
		afterTriggers.state->numstates = 0;

		/*
		 * Set the per-transaction ALL state to known.
		 */
		afterTriggers.state->all_isset = true;
		afterTriggers.state->all_isdeferred = stmt->deferred;
	}
	else
	{
		Relation	conrel;
		Relation	tgrel;
		List	   *conoidlist = NIL;
		List	   *tgoidlist = NIL;
		ListCell   *lc;

		/*
		 * Handle SET CONSTRAINTS constraint-name [, ...]
		 *
		 * First, identify all the named constraints and make a list of their
		 * OIDs.  Since, unlike the SQL spec, we allow multiple constraints of
		 * the same name within a schema, the specifications are not
		 * necessarily unique.  Our strategy is to target all matching
		 * constraints within the first search-path schema that has any
		 * matches, but disregard matches in schemas beyond the first match.
		 * (This is a bit odd but it's the historical behavior.)
		 *
		 * A constraint in a partitioned table may have corresponding
		 * constraints in the partitions.  Grab those too.
		 */