Paul Ramsey <pramsey(at)cleverelephant(dot)ca> writes:
> Gotcha, done and now have an implementation that passes all our regression tests.
Very cool! So the next step, I guess, is to address your original problem
by cranking up the cost estimates for these functions --- have you tried
that yet? In principle you should be able to do that and not have any
bad planning side-effects, but this is all pretty new territory so maybe
some problems remain to be ironed out.
BTW, if you'd like me to review the code you added for this, I'd be happy
to do so. I've never looked at PostGIS' innards, but probably I can make
sense of the code for this despite that.
regards, tom lane