On Mon, Jun 5, 2023 at 10:19 PM Etsuro Fujita <etsuro.fujita@gmail.com> wrote: > To avoid this issue, I am wondering if we should modify > add_paths_to_joinrel() in back branches so that it just disallows the > FDW to consider pushing down joins when the restrictlist has > pseudoconstant clauses. Attached is a patch for that.
I think that custom scans have the same issue, so I modified the patch further so that it also disallows custom-scan providers to consider join pushdown in add_paths_to_joinrel() if necessary. Attached is a new version of the patch.
Good point. The v2 patch looks good to me for back branches.
I'm wondering what the plan is for HEAD. Should we also disallow foreign/custom join pushdown in the case that there is any pseudoconstant restriction clause, or instead still allow join pushdown in that case? If it is the latter, I think we can do something like my patch upthread does. But that patch needs to be revised to consider custom scans, maybe by storing the restriction clauses also in CustomPath?
