Re: guc patch: Make variables fall back to default values

On Tue, Mar 13, 2007 at 11:08:52AM -0400, Tom Lane wrote:
> Joachim Wieland <joe(at)mcknight(dot)de> writes:
> > On Tue, Mar 13, 2007 at 10:19:54AM -0400, Tom Lane wrote:
> >> Well, they *are* strings as long as they're "custom". Once a
> >> DefineCustomFoo has been executed, there (should be) no difference
> >> between a "custom" variable and a hard-wired one.

> > The code in question is the only place that calls one of the
> > DefineCustom*Variable functions. But those functions set
> > var->group = CUSTOM_OPTIONS what makes variables look like custom variables
> > defined via SQL or the config file but in reality they aren't. Hence the
> > confusion of the type assertion.

> My point here that you shouldn't be using var->group to make any
> semantic choices. That's supposed to be a label for user convenience,
> nothing else.

Then what is the criterion to tell what is a custom variable and what isn't?
If it contains a dot in the name it is? This wouldn't resolve the problem at
hand either... :-(

We might have to think about custom variables as a whole, what we have now
seems like a very unclear definition and everybody has his own opinion about
what it is and how it works (and I'm not excluding myself here :-)).

Joachim