Richard Guo <guofengli...@gmail.com> writes: > On Tue, Feb 7, 2023 at 2:12 PM Tom Lane <t...@sss.pgh.pa.us> wrote: >> I don't see any change in this query plan when I remove that code, so >> I'm not sure you're explaining your point very well.
> To observe an obvious plan change, we can add unique constraint for 'a' > and look how outer-join removal works. Ah. Yeah, that's pretty convincing, especially since v15 manages to find that optimization. Pushed with a test case. regards, tom lane