From: Tom Lane <tgl@sss.pgh.pa.us>
To: Justin Pryzby <pryzby@telsasoft.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: no MCV list of tiny table with unique columns
Date: Wed, 02 Nov 2016 16:05:46 -0400
Message-ID: <26162.1478117146@sss.pgh.pa.us> (raw)
In-Reply-To: <20161102185318.GA3987@telsasoft.com>
References: <20161102185318.GA3987@telsasoft.com>
List-Unsubscribe: <mailto:majordomo@postgresql.org?body=unsub%20pgsql-performance>
Justin Pryzby <pryzby@telsasoft.com> writes:
> I believe the join is being (badly) underestimated, leading to a crappy plan
> involving multiple nested loop joins, which takes 2.5 hours instead of a
> handful of seconds; I believe that might be resolved by populating its MCV
> list..
With only two rows in the table, I'm not real sure why you'd need an MCV
list. Could we see the actual problem query (and the other table
schemas), rather than diving into the code first?
regards, tom lane
--
Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-performance
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, pryzby@telsasoft.com
Subject: Re: no MCV list of tiny table with unique columns
In-Reply-To: <26162.1478117146@sss.pgh.pa.us>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox