Re: no MCV list of tiny table with unique columns

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Justin Pryzby <pryzby(at)telsasoft(dot)com>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: no MCV list of tiny table with unique columns
Date: 2016-11-02 20:05:46
Message-ID: 26162.1478117146@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-performance

Justin Pryzby <pryzby(at)telsasoft(dot)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

In response to

Responses

Browse pgsql-performance by date

  From Date Subject
Next Message Justin Pryzby 2016-11-02 20:19:55 Re: no MCV list of tiny table with unique columns
Previous Message Joao Junior 2016-11-02 19:06:05 archive_command too slow.