On Fri, 9 Oct 2020 at 12:16, Tom Lane <t...@sss.pgh.pa.us> wrote: > > > Perhaps the right fix is to modify clamp_row_est() with: > > I thought of that too, but as you say, if the rowcount has overflowed a > double then we've got way worse problems. It'd make more sense to try > to keep the count to a saner value in the first place.
I wonder if there was something more logical we could do to maintain sane estimates too, but someone could surely still cause it to blow up by writing a long series of clause-less joins. We can't really get away from the fact that we must estimate those as inner_rows * outer_rows I admit it's annoying to add cycles to clamp_row_est() for such insane cases. David
