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

On 7/28/13 10:49 PM, Tom Lane wrote:
> Josh Berkus <josh@agliodbs.com> writes:
>>> I think if we can design conf.d separately for config files of management tools, then
>>> it is better to have postgresql.auto.conf to be in $PGDATA rather than in
>>> $PGDATA/conf.d
>
>> One of the biggest current complaints about recovery.conf from
>> Debian/Ubuntu users is the fact that it lives in $PGDATA.  Won't we just
>> get the same thing here?
>
> I don't think that's the same case, but ... why exactly don't they like
> recovery.conf, and can you show that the location of the file has
> anything to do with the underlying complaint?

Here is a quick survey of config files:

RHEL6:
Cluster configuration file at /etc/sysconfig/pgsql, writeable by root. 
postgresql.conf is in $HOME/8.4/data

Debian Squeeze:
All configuration files in /etc/postgresql/8.4/main and are owned by the 
postgres user.

That last one shows why there's a complaint, and why it's 75% due to 
location rather than split role.  Debian users expect all of the config 
files to be relocated to /etc/postgresql or /etc/postgresql-common. 
Those files are also writeable by the postgres user.  recovery.conf 
doesn't fit that model, and people don't like that.  The admin who has 
to manage servers with puppet would be much happier if recovery.conf was 
in the /etc/postgresql tree they are already managing.  I get this 
complaint every single time I introduce an experienced Debian admin to 
PostgreSQL replication setup.  They aren't sure whether it's the 
packagers or PostgreSQL that is to blame for recovery.conf being in 
$PGDATA instead of /etc, but it's obvious to them someone has screwed up.

Given that Debian is the major example of a relocated postgresql.conf in 
the field, and that work has been done such that a) all config files are 
in /etc and b) they are all writeable by the postgres user, I don't 
understand why people are suggesting the auto.conf file or conf.d 
directory will go anywhere else on that platform anymore.  I think the 
only claims that are suggesting otherwise are thinking about an older, 
now unsupported version of the Debian packaging.  Debian packaging 
absolutely will want to relocate any new files added here into their 
/etc directory tree as well, where they will be writeable.  They will 
not go into the $PGDATA directory.

-- 
Greg Smith   2ndQuadrant US    greg@2ndQuadrant.com   Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.com