Re: better page-level checksums

On Tue, Jun 14, 2022 at 3:01 PM Peter Geoghegan <pg(at)bowt(dot)ie> wrote:
> A tool like pg_filedump or a backup tool can easily afford this
> overhead. The only cost that TDE has to pay for this added flexibility
> is that it has to set one of the PD_* bits in a code path that is
> already bound to be very expensive. What's so bad about that?
>
> Honestly, I'm a bit surprised that you're pushing back on this
> particular point. A nonce for TDE is just something that code in
> places like bufpage.h ought to know about. It has to be negotiated at
> that level, because it will in fact affect a lot of callers to the
> bufpage.h functions.

Peter, unless I have missed something, this email is the very first
one where you or anyone else have said anything at all about a PD_*
bit. Even here, it's not very clear exactly what you are proposing.
Therefore I have neither said anything bad about it in the past, nor
can I now answer the question as to what is "so bad about it." If you
want to make a concrete proposal, I will be happy to tell you what I
think about it.

--
Robert Haas
EDB: http://www.enterprisedb.com