Robert Haas <robertmhaas@gmail.com> writes:
> I'm alarmed by your follow-on statement that the current code can't
> handle the two-levels of removable join case. Seems like it ought to
> form {B C} as a path over {B} and then {A B C} as a path over {A}.
Actually I think it ought to form {A B} as a no-op join and then be able
to join {A B} to {C} as a no-op join. It won't recognize joining A to
{B C} as a no-op because the RHS isn't a baserel. But yeah, I was quite
surprised at the failure too. We should take the time to understand why
it's failing before we go further. I ran out of steam last night but
will have a look into that today.
regards, tom lane
