On Friday, September 26, 2014, Alvaro Herrera <alvhe...@2ndquadrant.com> wrote:
> David Johnston wrote: > > On Friday, September 26, 2014, Alvaro Herrera <alvhe...@2ndquadrant.com > <javascript:;>> > > wrote: > > > > > Tom Lane wrote: > > > > > > > The impression I had was that Stephen was thinking of actually > setting > > > > min_val to 1 (or whatever) and handling zero or -1 in some > out-of-band > > > > fashion, perhaps by adding GUC flag bits showing those as allowable > > > > special cases. I'm not sure how we would display such a state of > affairs > > > > in pg_settings, but other than that it doesn't sound implausible. > > > > > > I would think that if we're going to have "out of band" values, we > > > should just use "off", not 0 or -1. > > > > Except "off" is not always semantically correct - some GUCs (not sure > which > > ones ATM) use zero to mean 'default'. I think -1 always means off. > > Instead of 0 and -1 we'd need 'default' and 'off' with the ability to > error > > if there is no meaningful default defined or if a feature cannot be > turned > > off. > > Sure, "off" (and other spellings of boolean false value) and "default" > where they make sense, and whatever other values that make sense. My > point is to avoid collapsing such logical values to integer/floating > point values just because the option uses a numeric scale. > > My comment was more about storage than data entry. I'm not sure, though, that we'd want to allow 0 as valid input even if it is acceptable for Boolean. David J.
