On Fri, May 7, 2021 at 7:35 PM Andrey Lepikhov <a.lepik...@postgrespro.ru> wrote: > On 6/5/21 14:11, Etsuro Fujita wrote: > > On Tue, Apr 27, 2021 at 3:57 PM Andrey V. Lepikhov > > <a.lepik...@postgrespro.ru> wrote: > >> One more question. Append choose async plans at the stage of the Append > >> plan creation. > >> Later, the planner performs some optimizations, such as eliminating > >> trivial Subquery nodes. So, AsyncAppend is impossible in some > >> situations, for example: > >> > >> (SELECT * FROM f1 WHERE a < 10) > >> UNION ALL > >> (SELECT * FROM f2 WHERE a < 10);
> >> We can choose async > >> subplans at the beginning of the execution stage. > >> For a demo, I prepared the patch (see in attachment). > >> It solves the problem and passes the regression tests. > > > > IIUC, another approach to this would be the > > patch you proposed before [1]. Right? > Yes. I think, new solution will be better. Ok, will review. I think it would be better to start a new thread for this, and add the patch to the next CF so that it doesn’t get lost. Best regards, Etsuro Fujita
