=?UTF-8?Q?Viktor_Bojovi=C4=87?= <viktor(dot)bojovic(at)gmail(dot)com> writes:
> my full vacuuming of one table runs still after four days. Is it safe to
> cancel it by pressing Ctrl+c?
I assume this is a pre-9.0 Postgres version?
Depending on how far along the vacuum actually is, there's a possibility
that trying to cancel it will cause a PANIC, but that will not damage
your data --- the worst consequence would be killing any other sessions
that are running concurrently.
regards, tom lane