Re: vacuum_cost_page_miss default value and modern hardware

Peter Geoghegan <pg@bowt.ie>

From: Peter Geoghegan <pg@bowt.ie>
To: Masahiko Sawada <sawada.mshk@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2021-01-07T02:42:38Z
Lists: pgsql-hackers
On Wed, Jan 6, 2021 at 5:39 PM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
> Perhaps you meant to decrease vacuumm_cost_page_miss instead of
> vacuum_cost_page_dirty?

You're right. Evidently I didn't write this email very carefully.
Sorry about that.

To say it again: I think that a miss (without dirtying the page)
should be cheaper than dirtying a page. This thread began because I
wanted to discuss the relative cost of different kinds of I/O
operations to VACUUM, without necessarily discussing the absolute
costs/time delays.

-- 
Peter Geoghegan



Commits

  1. Reduce the default value of vacuum_cost_page_miss.

  2. Cost based vacuum delay feature.