Re: PostgreSQL configuration

Stephan Szabo <sszabo(at)megazone(dot)bigpanda(dot)com> writes:
> On Mon, 12 Apr 2004, Bruce Momjian wrote:
>> I think the major problem with your -C & -D idea is that you require the
>> administrator to link the config file and data directory everytime you
>> start the db, and that might be error-prone.

> Well, AFAICS the patch doesn't require that actually, it merely allows the
> separation.

Well, it doesn't *require* it, but if you actually *use* the patch in
the proposed way then you end up with the error-prone need to specify
the correct combination of -C and -D on the command line. I think what
people are questioning is whether we can't find a variant solution that
avoids that risk.

The bottom line to me is that config versus data ought to be a one-to-
many relationship, at least if you accept the premise that shared config
is reasonable at all. Putting a datadir spec inside the config file
makes it impossible to share config files across datadirs, and so that
seems to conflict with the argument (which is being made in support of
this very same patch) that sharable config is good. On the other hand,
if you make data point to config then you have a very natural way to
manage the one-to-many relationship.

Separate -C and -D would make sense if it were a many-to-many
relationship (ie, you could sensibly use many different configs with the
same data dir), but the case for multiple configs with one data dir
seems pretty weak to me, and outweighed by the risk factors.

regards, tom lane