From: | Bruce Momjian <bruce(at)momjian(dot)us> |
---|---|
To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
Cc: | "David G(dot) Johnston" <david(dot)g(dot)johnston(at)gmail(dot)com>, yigongh(at)gmail(dot)com, pgsql-docs(at)lists(dot)postgresql(dot)org |
Subject: | Re: The suggestion of reducing autovacuum_vacuum_cost_delay should be documented |
Date: | 2020-05-12 23:30:56 |
Message-ID: | 20200512233056.GF4666@momjian.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-docs |
On Tue, May 12, 2020 at 07:26:07PM -0400, Tom Lane wrote:
> Bruce Momjian <bruce(at)momjian(dot)us> writes:
> > On Tue, May 12, 2020 at 03:38:16PM -0700, David G. Johnston wrote:
> >> The proposal is to document in versions 9.4 to 11 that the recommended value
> >> for the setting is 2ms while for reasons of continuity the default in these
> >> versions is 20ms.
> >> I don't really see any harm in it. Its not like the choice to reduce the value
> >> was made because of new features introduced in 12 - it was a re-evaluation of a
> >> 15 year old default.
>
> > Well, we really need to have some general discussion about whether
> > changing defaults in major releases should trigger a mention to change
> > the defaults in back branches. This is something that would have to be
> > discussed on the hackers list.
>
> It's not immediately obvious that the new default value established in
> version N is appropriate for version N-minus-several. Certainly, whatever
> testing was done to justify the new default wouldn't have been done on old
> versions; and there might have been relevant changes.
>
> In short: nope, I'm not on board with blindly back-patching such
> recommendations.
That was my analysis too.
--
Bruce Momjian <bruce(at)momjian(dot)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 +
From | Date | Subject | |
---|---|---|---|
Next Message | David G. Johnston | 2020-05-12 23:49:37 | Re: The suggestion of reducing autovacuum_vacuum_cost_delay should be documented |
Previous Message | Tom Lane | 2020-05-12 23:26:07 | Re: The suggestion of reducing autovacuum_vacuum_cost_delay should be documented |