Daniel Farina <daniel(at)heroku(dot)com> writes:
> Would these hypothetical extension-pairs be using the "options" device
> at startup time, or something else (possibly brand new)?
I'd argue for just translating them into "options", at least in the
near term. If they use some new mechanism then they would only work
with new servers, and it's generally not good for libpq to assume much
about what version of server it's working with, especially not when
sending an initial connection packet (when, by definition, it can't
know that for sure).
As far as changing such settings later in the session is concerned,
isn't that what SET is for?
regards, tom lane