"David G. Johnston" <david(dot)g(dot)johnston(at)gmail(dot)com> writes:
> I seem to recall a discussion a few years back but cannot find it searching
> online. The one post I did find was from 6 years ago and I was the only
> respondent and basically said the same or less than I am here.
I dug in the archives and came across a crude POC hack here:
https://www.postgresql.org/message-id/21693.1478376334@sss.pgh.pa.us
At the time I didn't want to pursue it further because of Andres'
pending work on redoing expression execution, but that's landed now.
regards, tom lane