On Wed, Oct 4, 2023 at 8:41 AM David Rowley <dgrowle...@gmail.com> wrote:
> On Sun, 1 Oct 2023 at 21:26, Andy Fan <zhihui.fan1...@gmail.com> wrote: > >> But overall, I'm more inclined to just go with the more simple "add a > >> cheap unordered startup append path if considering cheap startup > >> plans" version. I see your latest patch does both. So, I'd suggest two > >> patches as I do see the merit in keeping this simple and cheap. If we > >> can get the first part in and you still find cases where you're not > >> getting the most appropriate startup plan based on the tuple fraction, > >> then we can reconsider what extra complexity we should endure in the > >> code based on the example query where we've demonstrated the planner > >> is not choosing the best startup path appropriate to the given tuple > >> fraction. > > > > I think this is a fair point, I agree that your first part is good > enough to be > > committed first. Actually I tried a lot to make a test case which can > prove > > the value of cheapest fractional cost but no gain so far:( > > I've attached a patch with the same code as the previous patch but > this time including a regression test. > > I see no reason to not commit this so if anyone feels differently > please let me know. > > David > Patch LGTM. -- Best Regards Andy Fan
