On 2013-08-30 09:19:42 -0400, Stephen Frost wrote: > * Andres Freund (and...@2ndquadrant.com) wrote: > > On 2013-08-30 08:48:21 -0400, Stephen Frost wrote: > > > 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. > > wal_level and shared_buffers I can buy, but listen_addresses? The most > typical change there is going from localhost -> '*', but you've got to > be on the box to do that. Anything else and you're going to need to be > adding interfaces to the box anyway and hacking around in > /etc/network/interfaces or what-have-you.
Even if it requires to be on the box locally, I only need libpq for it. And it's not infrequent to allow additional, already configured interfaces. And even if not, what's the point of prohibiting listen_interfaces specifically? When the other very interesting variables have the same dangers? Doing this on a variable-by-variable basis will a) be a ridiculous amount of effort, b) confuse users which may not share our judgement of individual variables. > > > 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. > > You and Robert both seem to be of the opinion that this hack which > brings postgresql.conf into the database via ALTER SYSTEM is a-ok > because it's moving us "forward" in someone's mind, but it really is > developing a system configuration management system which *looks* like a > first-class citizen when it actually falls woefully short of that. It's what plenty of people want and it doesn't hurt people who do not want it. Yes. I think that's a step forward. > There is absolutely no question in my mind that this will be a huge > support pain, from the first "ALTER SYSTEM SET shared_buffers = blah; > SHOW shared_buffers;" to the "why can't my database start?!? it's > complaining it can't allocate memory but I keep changing postgresql.conf > and nothing works!" I'm simply not convinced that this is moving us > forward nor that we will end up with more benefit than pain from it. That will not show the changed shared_buffers. And it (afair) will throw a WARNING that shared_buffers couldn't be adjusted at this point. Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers