Re: Configure redux. - Mailing list pgsql-hackers

> WITH LOCATION would be great,.... That way you could distribute your
> databases across multiple physical disks a lot easier than looking up
> oid's
> and moving the db after it's been created, mounting it over the top of the
> cluster directory....

Actually "WITH LOCATION" already exists, but it works in two eays, either
you specify an environment variable which points to the directory, or you
have to compile postgresql with a define which allows the location to be
an absolute path.

They say the absolute path is a security issue, I honestly don't see how
as it must be accessed by the postgresql process. If you can create a
directory with that ownership, then you would presumably have enough
access to modify Postgresql to use any location you like.

Anyway, the hacker group seems to think that being able to specify a
directory is a security risk, and I'm sure its not a decision that will go
away easy. By the same token, however, I think mandating alternate
locations be in the environment table of the server process is insane. If
you can't specify actual directories, then the information belongs in the
configuration file. Does anyone seriously disagree with this statement?

My problem with postgresql configuration are ways you must do things.

If you want "pg_xlog" on a different volume, you must use symlinks. If you
want to put a database in an alternate location, you must either use
symlinks or specify an environment variable. If you want to share pg_ident
or pg_hba you have to use symlinks.

As *any* DBA will tell you, symlinks are not the production solution of
choice. They are not self documenting. They sometimes break archive
utilities i.e. some follow symlinks, some only save the link. Symlinks are
just plain messy in production. That's why I've really been pushing for
the configuration file to be *THE* configuration of the database system.

One should be able to print out postgresql.conf and "know" where
everything is and how it is configured. This knowledge should not depend
on knowing that symlinks are used or what environment variables are in
play.

The changes I suggest can get us closer to a single point of reference for
postgresql deployment.

>
> Just my $0.002 worth...

Mine too.

>
> ... John
>
> -----Original Message-----
> From: pgsql-hackers-owner@postgresql.org
> [mailto:pgsql-hackers-owner@postgresql.org] On Behalf Of
> pgsql@mohawksoft.com
> Sent: Wednesday, 12 May 2004 5:06 AM
> To: pgsql-hackers@postgresql.org
> Subject: [HACKERS] Configure redux. "WITH LOCATION," what do you think?
>
> I'm sorry to keep bringing this up, but I keep thinking that PostgreSQL is
> a
> PITA to configure. It isn't that I don't know how, or can't read the
> documents, it's just that there is too many things that can go wrong or
> leave me with the "How does that work?" feeling where I need to test
> before
> I implement.
>
> OK, here is what I think we need to do, and I am willing to take the point
> and do all of it:
>
> If postmaster is started with -D or with $PGDATA set to the location of a
> postgresql cluster directory, it will work as it has always worked.
>
> If the -D or the $PGDATA values do not point to a database cluster
> directory, it must point to either a postgresql.conf file, or a directory
> which contains "postgresql.conf." If it points to a directory, then that
> directory will be the assumed the default for pg_hba.conf and
> pg_ident.conf.
>
> The test for it being a cluster directory or a configuration directory
> will
> be the presence of "PG_VERSION." (any better suggestion would be welcome
>
> Within the postgresql.conf file, there will be about 4 additional
> configuration parameters:
>
> include='/somepath/coreopts.conf'
> hba_conf='/somepath/pg_hba.conf'
> ident_conf='somepath/pg_ident.conf'
> pgdata='/somepath/to/cluster'
>
> (Unfortunately we lose the ability to use a standard configuration across
> multiple databases, but I think this is a good compromise.)
>
> Additionally, rather than depend on environment variables for security, we
> can put acceptable database locations in the postgresql.conf file in the
> form of:
>
> altdb='/somealtpath'
>
> and we can use createdb as:
>
> CREATE DATABASE somedb with LOCATION 'altdb';
>
> What do you all think?
>
>
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