On Thu, 1 Feb 2024 at 16:29, Richard Guo <guofengli...@gmail.com> wrote: > > > On Thu, Feb 1, 2024 at 10:04 AM James Coleman <jtc...@gmail.com> wrote: >> >> I don't see any inherent reason why we must always assume that >> gather_grouping_paths will always result in having at least one entry >> in pathlist. If, for example, we've disabled incremental sort and the >> cheapest partial path happens to already be sorted, then I don't >> believe we'll add any paths. And if that happens then set_cheapest >> will error with the message "could not devise a query plan for the >> given query". So I propose we add a similar guard to this call point. > > > I don't believe that would happen. It seems to me that we should, at > the very least, have a path which is Gather on top of the cheapest > partial path (see generate_gather_paths), as long as the > partially_grouped_rel has partial paths.
It will have partial paths because it's nested inside "if (partially_grouped_rel && partially_grouped_rel->partial_pathlist)" David
