Horton

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

Stephen Frost <sfrost@snowman.net>

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From: Stephen Frost <sfrost@snowman.net>
To: Bruce Momjian <bruce@momjian.us>
Cc: Josh Berkus <josh@agliodbs.com>, Tom Lane <tgl@sss.pgh.pa.us>, Andres Freund <andres@2ndquadrant.com>, Greg Stark <stark@mit.edu>, Alvaro Herrera <alvherre@2ndquadrant.com>, Fujii Masao <masao.fujii@gmail.com>, Robert Haas <robertmhaas@gmail.com>, Amit Kapila <amit.kapila@huawei.com>, Dimitri Fontaine <dimitri@2ndquadrant.fr>, pgsql-hackers@postgresql.org
Date: 2013-08-05T18:52:40Z
Lists: pgsql-hackers 
* Bruce Momjian (bruce@momjian.us) wrote:
> On Mon, Aug  5, 2013 at 11:16:24AM -0700, Josh Berkus wrote:
> > I don't think this is a small thing.  I really think we'll get a LOT of
> > blowback from sysadmins -- and maybe even refusals to upgrade -- if we
>                              ----------------------------------
> 
> Really?  Is that a reasonable statement?

I don't believe Josh was saying that in jest..  I certainly believe that
it could happen.

> > As I've said before, I think the disable switch can be a follow-up patch
> > to the main ALTER SYSTEM SET patch.

Even if it's a different patch, it should go in at the same time, imv..

> You are mixing the behaviors of disabling the ALTER SYSTEM SET command
> with recognizing ALTER SYSTEM SET settings already made --- the later
> would be to fix a problem with the server not starting.  

That's a good point.

> However,
> frankly, these are flat files, so I don't see a problem with having the
> administrator modify the flat file.

Admins on Ubuntu or Debian or a host of their derivatives aren't going
to be looking in $PGDATA for config files that they have to hand-modify
to fix something the DBA did.  When they eventually figure it out,
they're going to be *very* unhappy.

> Would disabling the ALTER SYSTEM SET command also disable recognizing
> any ALTER SYSTEM SET commands already performed?  Maybe that was already
> understood, but I missed that point.

I don't have an answer to that one, though I do like the idea of a
switch that says "only read the settings from my postgresql.conf file".

		Thanks,
			
			Stephen