From: | Robert Haas <robertmhaas(at)gmail(dot)com> |
---|---|
To: | Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> |
Cc: | PostgreSQL Hackers <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: strange explain in upstream - subplan 1 twice - is it bug? |
Date: | 2016-07-07 19:57:05 |
Message-ID: | CA+Tgmob=vjYTFe5NDa5nHRUapSb51e7AYY3evWUnGNayMr6sQQ@mail.gmail.com |
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Lists: | pgsql-hackers |
On Wed, Jun 1, 2016 at 7:29 AM, Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> wrote:
> Hi
>
> When I tested some queries, I found strange plan
>
> postgres=# explain analyze select s.nazev, o.nazev, o.pocet_obyvatel from
> (select nazev, array(select id from obce_pocet_obyvatel where okresy.id =
> okres_id order by pocet_obyvatel desc limit 3) as obceids from okresy) s
> join obce_pocet_obyvatel o on o.id = ANY(obceids) order by 1, 3 desc;
The EXPLAIN plan you posted certainly looks weird, since I wouldn't
expect SubPlan 1 to be displayed twice, but I'm wondering if it's a
display artifact rather than an actual defect in the plan.
Just out of curiosity, what does the output look like with FORMAT JSON
or similar?
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
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