> > If I do switch to RANGE types, I think [2,2] would make sense in this case. > Using unbounded ranges might make sense if I wanted to express something > like "Use up to 1 cup of flour" or "You'll need at least 3 cups of water". > In these cases: Flour: [0, 1] - "optional, but maximum of 1-cup"; you cannot supply a negative amount of ingredient... Water: [3, ) - "at least three cups, but remember you will have to pay the water bill at some point..." The water example implies some need to flag the quantity as needing an explanation. In this case I would probably say "[3,3]" and set a flag so that you can describe, in words, those situations where additional water would be OK. Mabye some kind of "quantity_precision" flag with possible values of [EXACT,APPROXIMATE,MINIMUM,MAXIMUM]. The reason I say this is because the value of storing an amount as a value is that it can be used in calculations and it is difficult to use infinity in calculations. By storing a finite range you can more readily use the values in calculations and when you care about whether the value is "required" or "suggested" you have a flag you can query to tell you which it is. David J. -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
