Richard Guo <guofengli...@gmail.com> writes: > On Fri, Nov 17, 2023 at 11:38 AM Tom Lane <t...@sss.pgh.pa.us> wrote: >> That line of argument also leads to the conclusion that it'd be >> okay to expose info about the ordering of the CTE result to the >> upper planner. This patch doesn't do that, and I'm not sufficiently >> excited about the issue to go write some code. But if someone else >> does, I think we shouldn't exclude doing it on the grounds of wanting >> to preserve an optimization fence. The fence is sort of one-way >> in this line of thinking: information can propagate up to the outer >> planner level, but not down into the CTE plan.
> Exactly! Thanks for the detailed explanation. OK. I pushed the patch after a bit more review: we can simplify things some more by using the subroot->parse querytree for all tests. After the previous refactoring, it wasn't buying us anything to do some initial tests with the raw querytree. (The original idea of that, I believe, was to avoid doing find_base_rel if we could; but now that's not helpful.) regards, tom lane