On Friday, September 26, 2014, Alvaro Herrera <
alvherre@2ndquadrant.com> 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.
David J.
