On Wed, 31 Jan 2024 at 18:58, Ashutosh Bapat <ashutosh.bapat....@gmail.com> wrote: > with patch > Merge Append (cost=6.94..18.90 rows=198 width=4)
> without patch > Sort (cost=19.04..19.54 rows=198 width=4) > Those numbers are higher than 1% (#define STD_FUZZ_FACTOR 1.01) but > slight variation in all the GUCs that affect cost, might bring the > difference closer to STD_FUZZ_FACTOR. > > Given how close they are, maybe it's not such a good idea to > backpatch. The reason those numbers are close is because I reduced the row count on the test tables to a point where we only just get the Merge Append plan with a small margin. I don't see the test case costs as a relevant factor for if we backpatch or not. What is relevant are things like: For: * It's a clear bug and what's happening now is clearly wrong. * inheritance/partitioned table plan changes for the better in minor versions Against: * Nobody has complained for 13 years, so maybe it's unlikely anyone is suffering too much. * Possibility of inheritance/partitioned table plans changing for the worse in minor versions For now, I'm on the fence on this one. David
