Re: location of the configuration files

Bruce Momjian wrote:

>Well, in a sense, it trades passing one parameter, PGDATA, for another. 
>I see your point that we should specify configuration first, and let
>everything pass from there.  However, it does add extra configuration
>parameters, and because you still need to specify/create pgdata, it adds
>an extra level of abstraction to setting up the server.
>
While this is true, it is not uncommon, and it is more or less expected 
by most UNIX admins.

>
>Also, there is nothing preventing someone from symlinking the
>configuration files from pgdata to somewhere else.
>
Stop!!!  symlinks are not sufficient. When happens when a native Win32 
version comes out? there are no symlinks. Also, most of the admins I 
know don't like to use simlinks as they are not self documenting. 
Symlinks are "bad."

>
>I don't think separate params for each config file is good.  At the
>most, I think we will specify the configuration _directory_ for all the
>config files, perhaps pgsql/etc, and have pgdata default to ../data, or
>honor $PGDATA.  That might be the cleanest.
>
The problem with that is that you are back to symlinking shared files. 
Symlinks are a kludge.

>
>Of course, that now gives us $PGCONFIG and $PGDATA, and possible
>intraction if postgresql.conf specifies a different pgdata from $PGDATA.
>As you can see, it could get messy.
>
I don't see it as very messy, for instance:

postmaster -C /etc/postgres/postgresql.conf -D /RAID0/postgres -p 5432
postmaster -C /etc/postgres/postgresql.conf -D /RAID1/postgres -p 5433

That looks like a real clean way to run multiple PostgreSQL servers on 
the same box using the same configuration files.

>And, if you specify pgdata in postgresql.conf, it prevents you from
>using that file by different postmasters.
>
Not true, command line parameters, as a rule, override configuration 
file defaults.

>
>My best guess would be to not specify pgdata in postgresql.conf, and
>have a new $PGCONFIG param to specify the configuration directory, but
>if we do that, $PGDATA/postgresql.conf becomes meaningless, which could
>also be confusing.  Maybe we don't allow those files to exist in $PGDATA
>if $PGCONFIG is used, _and_ $PGCONFIG is not the same as $PGDATA.  See,
>I am getting myself confused.  :-)
>
I think you are making it too complicated.

I wouldn't remove the default configration set, it would be useful as a 
failsafe or maintainence feature.