On Fri, 8 Sept 2023 at 09:41, Robert Haas <robertmh...@gmail.com> wrote: > > On Tue, Sep 5, 2023 at 8:07 AM Richard Guo <guofengli...@gmail.com> wrote: > > Yeah, this seems an omission in commit 45be99f8. > > It's been a while, but I think I omitted this deliberately because I > didn't really understand the value of it and wanted to keep the > planning cost down.
I think the value is potentially not having to repeatedly execute some expensive rescan to the nested loop join once for each outer-side tuple. The planning cost is something to consider for sure, but it seems strange that we deemed it worthy to consider material paths for the non-parallel input paths but draw the line for the parallel/partial ones. It seems to me that the additional costs and the possible benefits are the same for both. David
