> Yes, all the changes of a single statement
> that encountered an error
> from at trigger will be undone by the engine. At that point, you may
> commit or rollback - it doesn't matter.
>

Is it the same if there isn't any trigger? I mean, does the engine undo
all the changes of a single statement that encountered an error?

The situation could be a single statement that tries to insert lots of
registers in a non-empty table and violates a unique key constraint in
the middle of the procces.

Thank you.

Juan Pedro