Re: The order of postgresql.conf parameters is potentially confusing. Very minor cosmetic bug or "niggle"!

On Wed, Sep 1, 2021 at 9:11 AM Pól Ua Laoínecháin <linehanp(at)tcd(dot)ie> wrote:

> I used pgtune to configure my system and received the following

...
> min_wal_size = 1GB
> max_wal_size = 4GB
> ...
> max_worker_processes = 2
> max_parallel_workers_per_gather = 1
> max_parallel_workers = 2
> max_parallel_maintenance_workers = 1
> [...]
>
> Surely then, the max_parallel_workers parameter should appear before
> the two others which depend on it?
>

I agree with this premise.

> I realise that these are not show-stoppers but at least in the case of
> the max_wal_ and min_wal_ size parameters, the inversion is a source
> of cognitive dissonance which a simple swapping of their respective
> positions would solve.
>
>
If one considers importance or utility when deciding upon the order then
max coming before min is the correct order; it is surely more important to
clamp the maximum than it is to ensure some minimum amount is present as a
performance optimization. A minor point, but the status quo is also
alphabetical.

Apparently pgTune has its own way of determining order, which also isn't
alphabetical and doesn't, at least for the workers, match the supplied
logic. As the program of lesser importance it should be changed to match
what the server does, not vice-versa. IOW, I agree that the mixup
regarding max/min WAL is worthy of being avoided - but the change should be
in pgTune, not postgresql.conf.

David J.