public inbox for [email protected]
help / color / mirror / Atom feedFrom: David Rowley <[email protected]>
To: Sami Imseih <[email protected]>
Cc: Nathan Bossart <[email protected]>
Cc: Greg Burd <[email protected]>
Cc: Robert Haas <[email protected]>
Cc: Robert Treat <[email protected]>
Cc: Jeremy Schneider <[email protected]>
Cc: pgsql-hackers <[email protected]>
Subject: Re: another autovacuum scheduling thread
Date: Fri, 20 Mar 2026 17:40:04 +1300
Message-ID: <CAApHDvpvkKYB6z-i1kiO9iePF0fz18-CaS9DZEWnSx1eO0RGFQ@mail.gmail.com> (raw)
In-Reply-To: <CAA5RZ0s7k6yve1Bq1OY+aXU3ifc_fvOiYkpE2VxwrUcHr2AtTg@mail.gmail.com>
References: <abGP87A3JPIXDG2I@nathan>
<CAA5RZ0tWonKY=E5U51i-J8s2EcRoLqtUQyWv+pQ4_rjFKSn+AA@mail.gmail.com>
<abGmNAVIPSqX124E@nathan>
<CAA5RZ0sZE-gfJ0c9HJkOk9XeFQwZL2wuJwrtOX+ZfUBLDcpFMA@mail.gmail.com>
<abMR6MQGQyyKWep4@nathan>
<CAApHDvqHXYCb=x0hHeR1e21ksqFNk4q3_zoPk6V-LLu0VL491Q@mail.gmail.com>
<abrOO8GCgkhMXvcq@nathan>
<[email protected]>
<CAApHDvpnR5zKb7LSB0idj4RPsV+=Dhtk+c5H0cZ4evN2hFDwCQ@mail.gmail.com>
<[email protected]>
<abwbDTu6OO6Izp4o@nathan>
<CAA5RZ0s7k6yve1Bq1OY+aXU3ifc_fvOiYkpE2VxwrUcHr2AtTg@mail.gmail.com>
On Fri, 20 Mar 2026 at 17:22, Sami Imseih <[email protected]> wrote:
> #5.
> + if (autovacuum_freeze_score_weight > 1.0)
> + effective_xid_failsafe_age /=
> autovacuum_freeze_score_weight;
> + if (autovacuum_multixact_freeze_score_weight > 1.0)
> + effective_mxid_failsafe_age /=
> autovacuum_multixact_freeze_score_weight;
> +
>
> Shouldn't this be "if (autovacuum_freeze_score_weight > 0.0)" ?
> A weight > 0 should always adjust the threshold, right? we should only
> prevent division by 0 here.
We really do want to ensure that tables are scaling very aggressively
when they reach the failsafe age. We don't want any quirky user
settings changing that. Prioritising anything else over a table at
failsafe age would be a very bad thing. The only point in doing what I
suggested was to allow users to give themselves more margin to get the
freezing done before failsafe age, certainly not less margin. In any
case, effective_xid_failsafe_age and effective_mxid_failsafe_age are
signed ints and default to 1.6 billion. There's just not enough
bit-space to divide them by any number much below 1.0 before they'll
wrap.
David
view thread (143+ messages) latest in thread
reply
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: [email protected]
Cc: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
Subject: Re: another autovacuum scheduling thread
In-Reply-To: <CAApHDvpvkKYB6z-i1kiO9iePF0fz18-CaS9DZEWnSx1eO0RGFQ@mail.gmail.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox