Re: Perplexing, regular decline in performance

Hi

On 2019-07-17 13:55:51 -0400, Alvaro Herrera wrote:
> Be careful with pg_buffercache though, as it can cause a hiccup in
> operation.

I think that's been fixed a few years back:

commit 6e654546fb61f62cc982d0c8f62241b3b30e7ef8
Author: Heikki Linnakangas <[email protected]>
Date:   2016-09-29 13:16:30 +0300

    Don't bother to lock bufmgr partitions in pg_buffercache.

    That makes the view a lot less disruptive to use on a production system.
    Without the locks, you don't get a consistent snapshot across all buffers,
    but that's OK. It wasn't a very useful guarantee in practice.

    Ivan Kartyshov, reviewed by Tomas Vondra and Robert Haas.

    Discusssion: <[email protected]>

so everything from 10 onwards ought to be fine.

Greetings,

Andres Freund