| From: | Andy Fan <zhihui(dot)fan1213(at)gmail(dot)com> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | PostgreSQL Hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org> |
| Subject: | Re: How is bushy plans generated in join_search_one_lev |
| Date: | 2020-08-27 00:46:23 |
| Message-ID: | CAKU4AWqTMSukLc_PnaftXBVnMS2A=KO17V3eDpdypFWKB=c+nQ@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Thu, Aug 27, 2020 at 8:05 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Andy Fan <zhihui(dot)fan1213(at)gmail(dot)com> writes:
> > I do see the README says we support bushy plans and I also see bushy
> > plans in real life (for example tpc-h Q20) like below. However I don't
> know
> > how it is generated with the algorithm in join_search_one_lev since it
> > always
> > make_rels_by_clause_join with joinrel[1] which is initial_rels which is
> > baserel.
>
> Hmm? Bushy plans are created by the second loop in join_search_one_level,
> starting about line 150 in joinrels.c.
>
> regards, tom lane
>
Yes.. I missed the second loop:(:(:(
--
Best Regards
Andy Fan
| From | Date | Subject | |
|---|---|---|---|
| Next Message | tsunakawa.takay@fujitsu.com | 2020-08-27 01:34:26 | RE: Implement UNLOGGED clause for COPY FROM |
| Previous Message | Tom Lane | 2020-08-27 00:05:04 | Re: How is bushy plans generated in join_search_one_lev |