Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> OK, so I tried to code this up. Adding the new amproc wasn't too
> difficult (see attached). It wasn't obvious to me how to tie it into
> the tuplesort infrastructure, though, so instead of wasting time
> guessing what a sensible approach might be I'm going to use one of my
> lifelines and poll the audience (or is that ask an expert?).
OK, I'll take a whack at improving this over the weekend.
regards, tom lane