does max_connections affect the query planner

From: Bob Jolliffe <bobjolliffe(at)gmail(dot)com>
To: pgsql-performance(at)lists(dot)postgresql(dot)org
Subject: does max_connections affect the query planner
Date: 2019-09-17 08:40:53
Message-ID: CACd=f9fE5k6FNc=zovUY0ohEJcYhqasdW+=bm2_6Y-H9UDTvGQ@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-performance

Hi

We are trying to diagnose why postgres might be making poor decisions
regarding query plans. One theory is that it does not assume it has
the memory suggested in effective_cache_size.

We do know that max_connections is set quite high (600) when we don't
really expect more than 100. I wonder does the planner take
max_connections x work_mem into account when considering the memory it
has potentially available?

Regards
Bob

Responses

Browse pgsql-performance by date

  From Date Subject
Next Message Tom Lane 2019-09-17 14:13:40 Re: does max_connections affect the query planner
Previous Message Amarendra Konda 2019-09-14 04:24:43 Re: Query execution time Vs Cost