Re: Disabling ALTER SYSTEM SET WAS: Re: ALTER SYSTEM SET command to change postgresql.conf parameters

On Tue, Aug 6, 2013 at 12:40:12PM +0200, Cédric Villemain wrote:
> > > Again, what are we trying to achieve?!
> >
> > no idea - wondering about that myself...
>
> It seems we are trying to add grammar for modifying postgresql.conf.
> Something we can already do easily in a standard extension, but without
> grammar changes.
>
> Maybe better to provide a contrib/ to modify config, then design what we can
> achieve more with an ALTER SYSTEM command.

Let's look at the problems:

* remote users can lock themselves out of the server
* interconnected GUC variables are complex to change
* need a way to disable this feature

Given the above, I am not sure I see a way forward for ALTER SYSTEM SET.
One compromise that avoids the problems above would be to have a limited
feature called ALTER LOG SET that only controls logging parameters, but
I am not sure there is enough use-case there.

This is not a zero-cost feature as we would be giving people _two_ ways
to configure Postgres, and two ways to find a fix if it is broken, so we
have to have a clear win to implement this. Also, if you have broken
the system via ALTER SYSTEM SET, you might need to edit flat files to
fix it, adding further complexity and limitations if someone only knows
the SQL method of configuration. Given that, and the problems above, I
reluctantly just don't see how this features moves us forward.

There seemed to be agreement on having a config.d, though.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ It's impossible for everything to be true. +