Date: Tue, 12 May 2020 17:41:01 -0400
From: Bruce Momjian <bruce@momjian.us>
To: yigongh@gmail.com, pgsql-docs@lists.postgresql.org
Subject: Re: The suggestion of reducing autovacuum_vacuum_cost_delay should
 be documented
Message-ID: <20200512214101.GA21408@momjian.us>
References: <158927918783.656.11973436145559215458@wrigleys.postgresql.org>
 <20200512214014.GD4666@momjian.us>
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On Tue, May 12, 2020 at 05:40:14PM -0400, Bruce Momjian wrote:
> On Tue, May 12, 2020 at 10:26:27AM +0000, PG Doc comments form wrote:
> > The following documentation comment has been logged on the website:
> > 
> > Page: https://www.postgresql.org/docs/11/runtime-config-autovacuum.html
> > Description:
> > 
> > The `autovacuum_vacuum_cost_delay` setting changes to 2ms in PostgreSQL 12
> > but in the old Postgresql version, the default setting is still 20ms. I
> > would suggest adding a suggestion in the old document
> > to lower the autovacuum_vacuum_cost_delay as:
> > 
> > > The default value of autovacuum_vacuum_cost_delay is reduced to 2ms in
> > PostgreSQL 12. Reducing the autovacuum_vacuum_cost_delay will make the
> > autovacuum more aggressive and might reduce the vacuum cost for
> > write-intensive workload on big table.
> 
> Uh, we usually don't suggest new defaults in back branches.

Basically, what I am saying is that if you want this, it would be a new
behavior that would need general discussion.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EnterpriseDB                             https://enterprisedb.com

+ As you are, so once was I.  As I am, so you will be. +
+                      Ancient Roman grave inscription +