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

On Tue, Aug 20, 2013 at 10:26 AM, Alvaro Herrera
<alvherre(at)2ndquadrant(dot)com> wrote:
> Amit Kapila escribió:
>
>> 3. postgresql.conf will contain include directive in below form:
>> #include = 'postgresql.auto.conf'
>> Whenever user wants to use Alter System, he needs to enable it
>> after first time using ALTER SYSTEM.
>
> This seems wrong to me. If the auto file is read by an include line in
> postgresql.conf, what is its priority w.r.t. files placed in an
> hypothetical conf.d directory? Hopefully snippets put in conf.d/ by
> puppet/chef will override the settings in postgresql.conf (i.e. conf.d/
> should be processed after postgresql.conf, not before); and hopefully
> ALTER SYSTEM will in turn override conf.d. I see no way to have ALTER
> SYSTEM handled by an include line, yet still have it override conf.d.

I think the behavior of overriding can be controlled by location of
include directive of conf.d directory or include location of auto file
whichever is later will override.
User can change the priority by changing location of include directive.

> If we want to make ALTER SYSTEM disable-able from postgresql.conf, I
> think it should be an explicit option, something like
> enable_alter_system = on
> or something like that.

I think this would be an easier way to handle disabling, but the only
question is whether this feature deserves a new config parameter?

With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com