Re: [HACKERS] Bug in WAL backup documentation

On Sun, 2006-11-05 at 11:10 -0500, Tom Lane wrote:
> "Simon Riggs" <simon@2ndquadrant.com> writes:
> > On Sat, 2006-11-04 at 13:29 -0500, Tom Lane wrote:
> >> Looking back in the archives, I note that one of the arguments for
> >> making the server use relative paths everywhere was so that it'd be
> >> robust against things like DBAs moving directories that contain live
> >> postmasters.  If we provide a %P option, or otherwise encourage people
> >> to write scripts that depend on the absolute path of $PGDATA, we'd lose
> >> some of this robustness.
>
> > I think I can fulfil Bernd, Florian and Martijn's wishes by supplying an
> > additional substitutable parameter %d which is replaced by the DataDir.
>
> This fails to respond to the concern that DataDir might be out-of-date.

I'm not suggesting that the option is necessary, but I am suggesting
offering it to those who consider it useful.

Let's allow it, but document the concern about its use in certain
circumstances.

I'm pretty sure most people don't move live postmasters very frequently,
plus it isn't clear to me why we should support the people that want
that to do that, yet not the people who want the absolute-path option.

--
  Simon Riggs
  EnterpriseDB   http://www.enterprisedb.com