Re: [HACKERS] Proposal : Parallel Merge Join
От | Dilip Kumar |
---|---|
Тема | Re: [HACKERS] Proposal : Parallel Merge Join |
Дата | |
Msg-id | CAFiTN-uRuD9acs_yU22e2=OG=dr_isUyzRwu7coAM-cPE=Zfgg@mail.gmail.com обсуждение исходный текст |
Ответ на | Re: [HACKERS] Proposal : Parallel Merge Join (Tomas Vondra <tomas.vondra@2ndquadrant.com>) |
Список | pgsql-hackers |
On Thu, Dec 29, 2016 at 3:15 AM, Tomas Vondra <tomas.vondra@2ndquadrant.com> wrote: > FWIW, I've done quite a bit of testing on this patch, and also on the other > patches adding parallel index scans and bitmap heap scan. I've been running > TPC-H and TPC-DS on 16GB data sets with each patch, looking for regressions > or crashes. Thanks for looking into this. > > I haven't found any of that so far, which is good of course. It however > seems the plan changes only for very few queries in those benchmarks with > any of the patches, even after tweaking the costs to make parallel plans > more likely. You can also try with reducing random_page_cost (that will help parallel merge join with index scan), in case your data fits in memory and you are ensuring warm cache environment. -- Regards, Dilip Kumar EnterpriseDB: http://www.enterprisedb.com
В списке pgsql-hackers по дате отправления: