Re: How is bushy plans generated in join_search_one_lev - Mailing list pgsql-hackers

From Tom Lane
Subject Re: How is bushy plans generated in join_search_one_lev
Date
Msg-id 2987895.1598486704@sss.pgh.pa.us
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In response to How is bushy plans generated in join_search_one_lev  (Andy Fan <zhihui.fan1213@gmail.com>)
Responses Re: How is bushy plans generated in join_search_one_lev  (Andy Fan <zhihui.fan1213@gmail.com>)
List pgsql-hackers
Andy Fan <zhihui.fan1213@gmail.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



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