On Thursday, November 16, 2023, 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. >
This is indeed my understanding of what materialized means. Basically, the CTE is done first and in isolation; but any knowledge of its result shape can be used when referencing it. David J.
