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

> Everything was already *not* hunky-dory as soon as you did that, since
> a SIGHUP would have had the same problem.
> 
> I'd be inclined to think that ALTER SYSTEM SET should not be allowed to
> modify any PGC_POSTMASTER parameters.

That makes alter system set a bunch less useful, but might be
insurmountable.

Anyway, I also regard this as a problem we need to resolve now that we
have the config directory if we expect people to build autotuning tools.
 Once someone is relying on an autotuning tool which drops a file in
config/, it becomes a real problem that there are uncommented
PGC_POSTMASTER options in the default postgresql.conf.

I'm not sure what the solution to that problem should be, but I do know
that we're going to hear it a lot from users as includes and the config
directory get more common.  Certainly any solution which says "first,
manually edit postgresql.conf" makes the config directory into a kind of
joke.

-- 
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com