Re: Why does TRUNCATE require a special privilege?

On 1/16/26 13:15, Marcelo Fernandes wrote:
> Those operations do different things, sure.
>
> But from a roles/privilege framework perspective, why would you want to give
> certain users the DELETE privilege whereas others you want to give them
> only the TRUNCATE privilege?
>
> Are we saying to a user that "You need a different level of privilege because
> you are about to cause a MVCC-unsafe operation?".

The thing I see as difference worthy of separation is:

"CASCADE

Automatically truncate all tables that have foreign-key references
to any of the named tables, or to any tables added to the group due to
CASCADE.
"

Now the same end result can be done with:

delete from some_table:

where the FK's pointing at some_table have ON CASCADE DELETE. The
difference being a DBA has the option of creating the FKs with ON
CASCADE NO ACTION which would throw an error. In other words you can
prevent an unconstrained DELETE on some_table from removing all the
child records. With TRUNCATE ... CASCADE, you cannot, the potential for
harm is greater.

>
> Or is the privilege framework simply ruling "Do different things, have
> different permissions"?
>
> Marcelo.
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com