On Sat, 17 Oct 2020 at 06:00, Tom Lane <t...@sss.pgh.pa.us> wrote: > I'm confused now, because the v2 patch does remove those isnan calls?
I think that was a case of a last-minute change of mind and forgetting to attach the updated patch. > I rechecked the archives, and I agree that there's no data about > exactly how we could have gotten a NaN here. My guess though is > infinity-times-zero in some earlier relation size estimate. So > hopefully the clamp to 1e100 will make that impossible, or if it > doesn't then clamp_row_est() should still prevent a NaN from > propagating to the next level up. > > I'm good with the v2 patch. Thanks a lot for having a look. I'll proceed in getting the v2 which I sent earlier into master. For the backbranches, I think I go with something more minimal in the form of adding: if (outer_path_rows <= 0 || isnan(outer_path_rows)) outer_path_rows = 1; +else if (isinf(outer_path_rows)) + outer_path_rows = DBL_MAX; and the same for the inner_path_rows to each area in costsize.c which has that code. Wondering your thoughts on that. David