On Mon, Oct 4, 2021 at 1:48 PM Tom Lane <tgl@xxxxxxxxxxxxx> wrote: > My mental model of these things is that the target table is cross-joined > to the additional tables as though by a comma in FROM [...] Mine as well. I just managed to dredge up some history here though. Turns out you explicitly disabled this feature for 9.4 to make room for a future feature to allow left-joining the target table [0]. Is support for that feature still desired/planned? (If it's been permanently abandoned for whatever reason, then maybe it's safe just to revert 158b7fa?) [0]: https://github.com/postgres/postgres/commit/158b7fa6a34006bdc70b515e14e120d3e896589b Nikhil
