On Thu, May 27, 2021 at 12:21 PM Andrey V. Lepikhov <a.lepik...@postgrespro.ru> wrote: > > On 5/8/21 2:00 AM, Hywel Carver wrote: > > On Fri, May 7, 2021 at 8:23 AM Andrey Lepikhov > > <a.lepik...@postgrespro.ru <mailto:a.lepik...@postgrespro.ru>> wrote: > > Here I didn't work on 'unnecessary IS NOT NULL filter'. > > > > I've tested the new patch, and it is giving the same improved behaviour > > as the old patch. > Thank you for this efforts! > > I cleaned the code of previous version, improved regression tests and > rebased on current master. > > Also, I see that we could do additional optimizations for an > EC-generated selfjoin clause (See equivclass.patch for necessary > changes). Example: > explain (costs off) > select * from sj t1, sj t2 where t1.a = t1.b and t1.b = t2.b and t2.b = > t2.a; > QUERY PLAN > ----------------------------------------------------- > Seq Scan on sj t2 > Filter: ((a IS NOT NULL) AND (b = a) AND (a = b)) > (2 rows) > > But I'm not sure that this patch need to be a part of the self-join > removal feature because of code complexity.
The patch does not apply on Head anymore, could you rebase and post a patch. I'm changing the status to "Waiting for Author". Regards, Vignesh