Ron Johnson wrote: > Each of the daily/hourly/etc temperature readings are independent. > Therefore they should each have their own row in the "meteorology > readings" table. I *think* that breaks 3NF. If everything is, as you say, independent, then there can be no 3NF violation, because that only happens when you have functional dependencies within a table. The question that you raise is more a matter of deciding which aspects of a problem are data and which are data structure. -- Peter Eisentraut http://developer.postgresql.org/~petere/
