Re: ALTER SYSTEM SET command to change postgresql.conf parameters (RE: Proposal for Allow postgresql.conf values to be changed via SQL [review])

Stephen Frost escribió:
> * Amit Kapila (amit(dot)kapila16(at)gmail(dot)com) wrote:
> > So let me try to explain what I understood from above:
> >
> > 1. enable_alter_system a new GUC whose default value =off.
> > 2. Alter System will check this variable and return error (not
> > allowed), if this parameter is off.
> > 3. Now if user enables include directive in postgresql.conf, it will
> > enable Alter System as value of
> > enable_alter_system is on.
> > 4. User can run Alter System command to disable Alter System
> > "enable_alter_system = off".
> > Now even though include directive is enabled, but new Alter System
> > commands will not work, however
> > existing parameter's take into effect on restart/sighup.
>
> Yes. Not sure that it'd be terribly likely for a user to do that, but
> if they do it, so be it.

With this design, if you put enable_alter_system=off in auto.conf, there
is no way for the user to enable alter system again short of editing a
file in the data directory. I think this is one of the things that was
"forbidden" by policy; only files in the config directory needs to be
edited.

What I was proposing upthread is that enable_alter_system=off/on would
be present in postgresql.conf, and there is no include line for
auto.conf. That way, if the user wishes to enable/disable the feature,
they need to edit postgresql.conf to do so. ALTER SYSTEM doesn't offer
a way to disable itself. If ALTER SYSTEM is disabled via
enable_alter_system=off in postgresql.conf, the settings in auto.conf
are not read.

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