>> Not 100% correct. If the TRUNCATE fails during the execution, the AFTER
>> trigger won't be fired, so any action there won't be executed.
>
> But with proposed DDL triggers AFTER triggers will be fired. So all
> possible verifications should be done early.

Yes.

I was commenting on Dmitry's suggestion that BEFORE and AFTER triggers
are semantically equivalent. This might be from the POV of the
transaction in which table is truncated, but when we consider situations
where the transaction boundaries are crossed (external tables,
procedures, etc.) - this is no longer true.

Roman