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

On 2013-08-30 08:48:21 -0400, Stephen Frost wrote:
> * Dimitri Fontaine (dimitri(at)2ndQuadrant(dot)fr) wrote:
> > Stephen Frost <sfrost(at)snowman(dot)net> writes:
> > > The OPs people are the ones that will be upset with this because the DBAs
> > > will be modifying configs which OPs rightfully claim as theirs.
> >
> > If that's the problem you want to solve, there's no technical solution
> > that will put you at ease. That's a people and trust problem.
>
> I really just don't buy that- I've already put forward suggestions for
> how to deal with it, but no one here seems to understand the
> distinction. Modifying listen_addresses through ALTER SYSTEM is akin to
> ISC/bind allowing changes to its listen_addresses equivilant through
> dynamic DNS updates. Would it be possible to implement? Sure. Does it
> make any sense? Certainly not.

I very much want to change stuff like wal_level, listen_addresses and
shared_buffers via ALTER SYSTEM. Configuration variables like that
(PGC_POSTMASTER stuff mostly) are the prime reason why you actually need
to change postgresql.conf instead of changing per user/database
settings.
And you don't even need to do anything special to implement it. Because
it's already there.

> > We currently have no way that I know of to disable ALTER ROLE SET and
> > ALTER DATABASE SET effects, why do we need to provide that feature for
> > ALTER SYSTEM SET so much?
>
> Because we've got crap mixed into postgresql.conf which are bootstrap
> configs needed to get the system started. Those things, in my view
> anyway, fall much more into the category of "resources which should be
> managed outside the database" than pg_hba.conf.

I think the problem with your position in this thread is that you want
to overhaul the way our configuration works in a pretty radical
way. Which is fair enough, there certainly are deficiencies. But it's
not the topic of this thread.

Greetings,

Andres Freund

--
Andres Freund http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services