Re: max_slot_wal_keep_size comment in postgresql.conf

Isaac Morland <isaac.morland@gmail.com>

From: Isaac Morland <isaac.morland@gmail.com>
To: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Cc: Jeff Janes <jeff.janes@gmail.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2020-05-27T02:56:39Z
Lists: pgsql-hackers
On Tue, 26 May 2020 at 21:46, Kyotaro Horiguchi <horikyota.ntt@gmail.com>
wrote:

> At Tue, 26 May 2020 09:10:40 -0400, Jeff Janes <jeff.janes@gmail.com>
> wrote in
> > In postgresql.conf, it says:
> >
> > #max_slot_wal_keep_size = -1  # measured in bytes; -1 disables
> >
> > I don't know if that is describing the dimension of this parameter or the
> > units of it, but the default units for it are megabytes, not individual
> > bytes, so I think it is pretty confusing.
>
> Agreed. It should be a leftover at the time the unit was changed
> (before committed) to MB from bytes.  The default value makes the
> confusion worse.
>
> Is the following works?
>
> #max_slot_wal_keep_size = -1  # in MB; -1 disables


Extreme pedant question: Is it MB (10^6 bytes) or MiB (2^20 bytes)?

Commits

  1. Fix some mentions to memory units in postgresql.conf.sample