po 6. 3. 2023 v 9:16 odesÃlatel David Rowley <dgrowle...@gmail.com> napsal:
> On Mon, 6 Mar 2023 at 20:34, Pavel Stehule <pavel.steh...@gmail.com> > wrote: > > In one query I can see very big overhead of memoize node - unfortunately > with hits = 0 > > > > The Estimate is almost very good. See details in attachment > > Are you able to share the version number for this? > 15.1 - upgrade on 15.2 is planned this month > > Also, it would be good to see EXPLAIN ANALYZE *VERBOSE* for the > memorize plan so we can see the timings for the parallel workers. > default https://explain.depesz.com/s/fnBe disabled memoize https://explain.depesz.com/s/P2rP > The results of: > > EXPLAIN ANALYZE > SELECT DISTINCT ictc.sub_category_id > FROM ixfk_ictc_subcategoryid ictc > INNER JOIN item i ON i.item_category_id = ictc.sub_category_id > WHERE ictc.super_category_id = ANY > ('{47124,49426,49488,47040,47128}'::bigint[]); > > https://explain.depesz.com/s/OtCl would also be useful. That should give an idea of the ndistinct > estimate. I guess memorize thinks there are fewer unique values than > the 112 that were found. There's probably not much to be done about > that. The slowness of the parallel workers seems like a more > interesting thing to understand. > > David >
