Re: PostgreSQL configuration

Dennis Bjorklund <db@zigo.dhs.org> writes:
> On Thu, 8 Apr 2004 pgsql@mohawksoft.com wrote:
>> more flexable configuration based on the idea that configuration and data
>> are in SEPARATE locations is important.

> Why is it important and wouldn't it just make it harder to have several 
> database clusters (for example with different locale) or several versions 
> of pg installed at the same time?

My recollection of the arguments against were first that and second
reliability --- there was concern about getting config and data of
multiple installations mixed up if they weren't kept together.  In the
worst case you could conceivably bollix an installation unrecoverably
that way.  (Right now I do not think there is anything quite that
critical in postgresql.conf, but someday there might be.  My very vague
recollection is that the proposed patch changed things so that WAL and
DATA directories would be separately specified in the config file; if
correct, mismatching them definitely would be a great chance to shoot
oneself in the foot.)

I've recently had some very unpleasant experiences trying to install
test versions of MySQL on machines that already had older versions
installed normally.  It seems that MySQL *will* read /etc/my.cnf if it
exists, whether it's appropriate or not, and so it's impossible to have
a truly independent test installation, even though you can configure it
to build/install into nonstandard directories.  Let's not emulate that
bit of brain damage.
        regards, tom lane