There are third-party cancel messages. While it doesn't completely
remove the message instantly, it does reduce its visibility significantly.

Alright, here's an old topic, the trans-relational model. (At one time,
I was intrigued by it, since I don't live in the USA and therefore could
ignore US patents if I wanted to try to make money off it.)  One claim
for it was that certain run-time sorts or index builds could be
eliminated, although I seem to remember one of the big names cautioning
that there might always be a 'preferred order' (sorry if I've mis-quoted
and I don't mean to be sly, the people who publicized it remain deep
thinkers in my book).  After some study, undoubtedly inferior in parts,
I concluded that one could accomplish the same 'physical' effect if
every 'column' were indexed.

However, in certain cases, it seemed to me that even if Codd was
approving of it (or so I remember reading), it denied his goal of
'symmetric exploitation', reason being that it depended on projections
of columns that were 'adjacent' (my term) in the 'zig-zag' organization
of physical columns, eg., if the zigzag connected column a to b and b to
c but the query involved only columns a and c, then the result wouldn't
have what I think of as a 'pleasing' order, unless a sort were invoked.

I realize that a pleasing order is counter to relational dogma but when
it comes to the mundane domains such as dollars and dates that I've been
indoctrinated in all my life, I find ordering of those familiar domains
to be just as powerful, helpful and convenient as pretty much any logic
I'm aware of.  As far as I can tell, Codd's symmetric exploitation could
be achieved if every permutation of 'columns' were encoded in the
trans-relational intermediate layer.

I don't remember this aspect of that model ever being discussed here but
I contend it is just as reasonable as Codd's original intent, which was
in part to make access to data storage more intuitive.

Of course, I'd agree if Bob B said he was finding plonk maintenance
onerous these days, but I have my own kind of plonk to fall back on.  If
it wasn't already my practice, I'd have said the current state of cdt
was driving me to drink.