Re: Wrong rows estimations with joins of CTEs slows queries by more than factor 500

Richard Guo <guofenglinux@gmail.com> writes:
> On Sun, Jan 7, 2024 at 6:41 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Thanks for the report!  I guess we need something like the attached.

> +1.

Pushed, thanks for looking at it.

>> I'm surprised that this hasn't been noticed before; was the case
>> really unreachable before?

> It seems that this case is only reachable with Vars of an INSERT target
> relation, and it seems that there is no other way to reference such a
> Var other than using CTE.

I'm a little uncomfortable with that conclusion, but for the moment
I refrained from back-patching.  We can always add the patch to v16
later if we find it's not so unreachable.  (Before v16, there was
no find_base_rel here at all.)

            regards, tom lane